The Sports Supplements Tool from Thomas Solomon PhD.
Which sports supplements work for runners and endurance athletes?
Last updated on: 16th Jan 2023.
Next update coming: July 2023.
Next update coming: July 2023.
Optimal performance is achieved with a well-planned and monitored training load combined with good nutrition, sleep, and rest. Lots of athletes also choose to use supplements. However, sports supplements are a big and confusing business — you can easily get lost and waste a lot of time and money. This free tool is an up-to-date summary of all known scientific evidence determining the effect of sports supplements on exercise performance. It can be used in combination with my Recovery Magic Tool. I’ve designed these resources for scientists, practitioners, coaches, and athletes to help inform their decisions. I aim to keep them up-to-date as new evidence emerges.
If this is your first visit to this page, I strongly recommend reading the intro section below because it contains important info (reading time ~4-mins, 900-words). But, if you’ve already read the intro, click the arrow to jump to the tool.
To quote Louise Burke and John Hawley, “Modern sports nutrition offers a feast of opportunities to assist elite athletes to train hard, optimize adaptation, stay healthy and injury free, achieve their desired physique, and fight against fatigue factors that limit success.”. But, when I think about sports supplements, Ron Maughan’s poetry always rolls through my mind: “If it works, it’s probably banned… If it’s not banned, then it probably doesn’t work… There may be some exceptions.”
Functional claims about a specific product are usually made in line with a specific functional dose of the active ingredient. If a product doesn’t contain a sufficient dose then it definitely won’t have the intended effect. Since the FDA/FSA do not systematically monitor supplements, you will often read “This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”. So, you need confidence in knowing exactly what’s in the bottle of pills or potion you are taking. And, as an athlete, quality control is essential! Without it, you may harm your health or take a contaminated product. And this is where things start to fall apart… Several reports have found major discrepancies between claimed contents and actual content (e.g. ephedra and CBD supplements), while even some controlled drugs, like the steroid hormone dehydroepiandrosterone (DHEA), have slipped through the net and been sold as dietary supplements. Plus, a 2022 systematic review found that 28% (or 875 out of 3132) supplements contained undeclared substances (including stimulants and anabolic steroids) that would trigger a positive doping test. This is worrying because, according to the NURMI study, ~50% of runners use supplements and a 2007 IAAF/World Athletics report found that ~85% of elite track and field athletes used dietary and/or sports supplements. The supplement business is booming!
Were appropriate baseline measurements made?
What were the baseline measurements?
When were the baseline measurements followed up?
Did the baseline measurements actually change after the intervention period?
Did the person make any other lifestyle changes during the intervention period?
Is the person being paid or sponsored to promote the product? And, so on…
To bring clarity where there is obscurity and help you understand whether “it” might actually improve performance and/or recovery, I’ve dug into all known scientific evidence on this topic and created a free resource to help inform your decisions.
High-quality robust evidence comes from studies with a randomized controlled trial (RCT) design. But, “cherry-picking” a study to confirm a bias is not a valid pursuit for informing practice. A systematic review examines all the “cherries” in a standardised way and, when the studies included in a systematic review are of high enough quality, a meta-analysis of all the available data can be completed. This produces an overall effect size along with a 95% confidence interval (the range of values the real effect size is likely to be found if the intervention is repeated) and a heterogeneity score (how variable the effect is). In simple words, a meta-analysis analyses all the “cherries” simultaneously to produce a useable effect size based on all available scientific evidence, enabling good decisions to be made. So, when I say that “I’ve dug into all known scientific evidence”, I mean that I’ve read all known systematic reviews and meta-analyses and summarised the evidence in this free resource: the Sports Supplements Tool.
But, before making any decisions, always conduct a cost-benefit analysis, where “cost” includes a combination of financial costs, time costs, moral costs, risk of contamination, potential performance impairment, and harm to health. For example:
If there is no benefit, there is no point in using the supplement.
If there is a benefit and no (or little) cost, use the supplement; you’d be foolish not to.
If the cost outweighs the benefit, do not proceed.
When making this kind of cost-benefit analysis, always remember that:
Taking a supplement does not “make” an athlete.
A supplement does not replace training.
A dietary supplement does not replace food.
There is no such thing as “exercise in a pill”.
It is also important to know that if you use supplements of any kind and/or prescription or over-the-counter drugs, you are also putting yourself at an increased risk of a positive test because they can contain prohibited substances. Minimise this risk by taking the following steps:
Educate yourself by completing European Athletics’ I Run Clean certification.
Familiarise yourself with the rules of your sport and with WADA’s prohibited list, which is updated every January.
If you are using ANY sports (or dietary) supplement, ensure it has been independently tested for prohibited substances by Informed Sport (or similar) → If in doubt, spit it out!
If you are using ANY over-the-counter or prescribed drugs, ALWAYS know what you are taking and get in the habit of cross-checking the Global DRO to help determine whether you need a TUE (therapeutic use exemption).
And, always remember that:
You are the only person responsible for what goes into your body.
Ignorance is not an excuse.
Stay educated. Be informed. Encourage others to do the same.
So, now you are ready for some science...
Functional claims about a specific product are usually made in line with a specific functional dose of the active ingredient. If a product doesn’t contain a sufficient dose then it definitely won’t have the intended effect. Since the FDA/FSA do not systematically monitor supplements, you will often read “This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”. So, you need confidence in knowing exactly what’s in the bottle of pills or potion you are taking. And, as an athlete, quality control is essential! Without it, you may harm your health or take a contaminated product. And this is where things start to fall apart… Several reports have found major discrepancies between claimed contents and actual content (e.g. ephedra and CBD supplements), while even some controlled drugs, like the steroid hormone dehydroepiandrosterone (DHEA), have slipped through the net and been sold as dietary supplements. Plus, a 2022 systematic review found that 28% (or 875 out of 3132) supplements contained undeclared substances (including stimulants and anabolic steroids) that would trigger a positive doping test. This is worrying because, according to the NURMI study, ~50% of runners use supplements and a 2007 IAAF/World Athletics report found that ~85% of elite track and field athletes used dietary and/or sports supplements. The supplement business is booming!
“It definitely works!”
I've lost count of how many times I’ve heard social media influencers spew the “I've used this and it was awesome” narrative. Regrettably, such phrases are also spouted from the mouths of “reputable” athletes, coaches, and other practitioners including scientists, nutritionists, psychologists, physiologists, and medical doctors on podcast, radio, and TV interviews when talking about a new pill, potion, or device. Frustratingly, these folks rarely say what “it” works for, what “it” is being compared to, or whether using “it” made them objectively faster, stronger, or healthier. When you see such narratives, think to yourself:
Were appropriate baseline measurements made?
What were the baseline measurements?
When were the baseline measurements followed up?
Did the baseline measurements actually change after the intervention period?
Did the person make any other lifestyle changes during the intervention period?
Is the person being paid or sponsored to promote the product? And, so on…
To bring clarity where there is obscurity and help you understand whether “it” might actually improve performance and/or recovery, I’ve dug into all known scientific evidence on this topic and created a free resource to help inform your decisions.
High-quality robust evidence comes from studies with a randomized controlled trial (RCT) design. But, “cherry-picking” a study to confirm a bias is not a valid pursuit for informing practice. A systematic review examines all the “cherries” in a standardised way and, when the studies included in a systematic review are of high enough quality, a meta-analysis of all the available data can be completed. This produces an overall effect size along with a 95% confidence interval (the range of values the real effect size is likely to be found if the intervention is repeated) and a heterogeneity score (how variable the effect is). In simple words, a meta-analysis analyses all the “cherries” simultaneously to produce a useable effect size based on all available scientific evidence, enabling good decisions to be made. So, when I say that “I’ve dug into all known scientific evidence”, I mean that I’ve read all known systematic reviews and meta-analyses and summarised the evidence in this free resource: the Sports Supplements Tool.
But, before making any decisions, always conduct a cost-benefit analysis, where “cost” includes a combination of financial costs, time costs, moral costs, risk of contamination, potential performance impairment, and harm to health. For example:
If there is no benefit, there is no point in using the supplement.
If there is a benefit and no (or little) cost, use the supplement; you’d be foolish not to.
If the cost outweighs the benefit, do not proceed.
When making this kind of cost-benefit analysis, always remember that:
Taking a supplement does not “make” an athlete.
A supplement does not replace training.
A dietary supplement does not replace food.
There is no such thing as “exercise in a pill”.
It is also important to know that if you use supplements of any kind and/or prescription or over-the-counter drugs, you are also putting yourself at an increased risk of a positive test because they can contain prohibited substances. Minimise this risk by taking the following steps:
Educate yourself by completing European Athletics’ I Run Clean certification.
Familiarise yourself with the rules of your sport and with WADA’s prohibited list, which is updated every January.
If you are using ANY sports (or dietary) supplement, ensure it has been independently tested for prohibited substances by Informed Sport (or similar) → If in doubt, spit it out!
If you are using ANY over-the-counter or prescribed drugs, ALWAYS know what you are taking and get in the habit of cross-checking the Global DRO to help determine whether you need a TUE (therapeutic use exemption).
And, always remember that:
You are the only person responsible for what goes into your body.
Ignorance is not an excuse.
Stay educated. Be informed. Encourage others to do the same.
So, now you are ready for some science...
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Caffeine, aka 1,3,7-trimethylxanthine, is a psychoactive drug that acts as a stimulant. While caffeine plays a role in calcium transport in muscle cells, it primarily affects your central nervous system by preventing adenosine binding to its receptors. This essentially blocks the “motivation-dampening” effects of adenosine, allowing “motivating” neurotransmitters like dopamine to continue to be released.
But caffeine has side effects, which can include a speedy heart rate (tachycardia), heart palpitations, headache, insomnia, peeing more, nervousness, gastrointestinal problems, and so on. If you develop any such symptoms as a consequence of caffeine intake before, during, or after races, you’re probably using too much. These side effects combined with frequent media stories about the risks of caffeine-containing high-sugar energy drinks, beg the important question: Is caffeine dangerous?
A 2017 systematic review of the potential adverse effects of caffeine concluded that “Consumption of up to 400 mg caffeine/day in healthy adults is not associated with overt, adverse cardiovascular effects, behavioral effects, reproductive and developmental effects, acute effects, or bone status. Evidence also supports consumption of up to 300 mg caffeine/day in healthy pregnant women as an intake that is generally not associated with adverse reproductive and developmental effects.” … Meanwhile, a 2017 umbrella review of meta-analyses concluded that “Coffee consumption seems generally safe within usual levels of intake”, and a 2022 systematic review of the side effects of caffeine supplementation in sport concluded that “Athletes using caffeine supplementation to enhance performance should be aware of both benefits and risks associated with the use of this substance in the sports context.” and that “From a practical perspective, supplementation with ~3.0 mg/kg of caffeine may be the dose of choice to combine the ergogenic benefits of caffeine with a low prevalence of side effects.”
So, caffeine is generally safe for most people if used within the recommended amounts.
Therefore, it is no surprise that a lot of people use caffeine as a way to start (and continue) their day. Bonjour, coffee. By extension, since endurance athletes are also people, we can assume that many athletes also indulge in a daily caffeine fix. But, we can be more objective and examine epidemiology. A survey of 24,808 adults in the National Health and Nutrition Examination Survey (NHANES) found that ~89% of US adults consume caffeine daily. Meanwhile, a 2022 survey of 254 endurance athletes found that 85% of athletes reported daily caffeine consumption (in beverages), 41% reported multiple daily caffeine intake, but only 24% reported purposefully using caffeine supplements prior to or during sessions and races. So…
Does caffeine improve performance — what do the systematic reviews say?
Caffeine taken either 60 to 90-mins before exercise or before and during exercise lowers RPE during exercise (moderate effect size) including during sustained high-intensity exercise (moderate to large effect size).
Caffeine taken either 60 to 90-mins before exercise or before and during exercise improves endurance performance during time-trials and time-to-exhaustion efforts (moderate effect size), muscle strength (moderate effect size), jumping (small effect size), and maximal power during very-short duration effort (small to moderate effect size).
For endurance exercise in hot conditions (≥30°C), the beneficial effects of pre-exercise caffeine ingestion persist with only trivial incremental effects on the exercise-induced rise in core temperature.
In skill-based sports, caffeine decreases the time taken to complete agility tests (moderate effect size). During team sports matches, caffeine increases total running distance (small to moderate effect size), distance covered at sprint velocity (small effect size), and the number of during-match sprints (small effect size).
The magnitude of the effect of caffeine is generally greater for aerobic exercise intensities compared to “anaerobic” type exercise intensities.
Caffeine added to carbohydrate intake during endurance exercise further improves performance vs. carbs alone (trivial to small additional effect).
Most work in this field has studied males and work studying females is sparse. That said, the current meta-analytical evidence shows that caffeine improves performance (muscular endurance and strength) in women (small to moderate effect sizes). More female-specific work is needed.
Cytochrome P450 1A2 is the enzyme responsible for ~95% of caffeine metabolism. This enzyme is coded by the CYP1A2 gene. Since folks can be “slow” or “fast” metabolizers of caffeine depending on the specific genotype of CYP1A2 they have, this might influence caffeine’s performance-enhancing effect. The current evidence shows some support for this — some but not all studies find that AA genotype folks (“fast” caffeine metabolizers) gain greater benefit from caffeine — but the genotype effects are small and inconsistent. More work in this area is needed.
Recent work has examined mouth-rinsing with caffeine as an alternative to ingestion: for performance-enhancing effects, some studies say “yay”, and many say “nay”. So, ingesting caffeine is the way to guarantee its effectiveness.
Lab-studies most often use isolated (powdered) caffeine but, in the real world, we drink coffee. So, you might wonder: Does coffee have the same performance-enhancing effect as isolated caffeine?. When standardised to the amount of caffeine, yes, coffee has the same effect. But the tricky thing is the amount of caffeine in coffee. The “average” cup of coffee is said to contain ~100 mg of caffeine. Since the performance-enhancing dose of caffeine is within 3 to 6 mg per kg bodyweight, 2-cups of coffee (~200 mg of caffeine) “should” provide ~3 mg/kg of caffeine for a person weighing 70 kg or ~4 mg/kg of caffeine for a person weighing 50 kg. But, the caffeine content in coffee is highly variable, influenced by the type of coffee bean, the preparation method, and the size of the cup. Consequently, caffeine concentrations vary between different coffee brands and even within the same brand. Therefore, the amount of caffeine in an “average” cup of coffee is an estimate with large margins of error. For general training, the performance-enhancing 2-cups of coffee rule-of-thumb might be fine but if you’re looking to exploit the performance-enhancing effect of caffeine for a race, it might be better to use a sports nutrition product with a known amount of caffeine.
Since so many folks consume caffeine (in coffee, tea, and other drinks), you might wonder: Does chronic caffeine use alter caffeine’s acute performance-enhancing effects? In 2019, Craig Pickering & John Kiely posed that exact question, concluding that habitual caffeine users may have a lesser performance-enhancing effect of caffeine but that this can likely be remedied by taking a slightly higher dose than the habitual dose. They also noted that short-term caffeine withdrawal prior to key events does not enhance the acute performance-enhancing effect of caffeine in folks who are habituated to caffeine. They also made the highly relevant point that “Given the individual response to caffeine, both in terms of habituation and ergogenesis, athletes should experiment with various doses and timing strategies when using caffeine to enhance performance”.
Caffeine is so potent it might be banned if discovered today but caffeine-containing plants have been used by humans since the dawn of breakfast. Consequently, caffeine intake has become socially acceptable, is safe for most people, and is so widely used that it would be impossible to regulate. Therefore, caffeine has become a “monitored substance” that is legal in the eyes of WADA and not currently on their prohibited list for in or out-of-competition use. However, always check the rules of your governing body, stay up-to-date with developments on WADA’s prohibited list, and check the rules of your race.
If you choose to use caffeine, a reasonable dose is:
3 to 6 milligrams (mg) of caffeine per kg body weight 30 to 60-minutes before a session or race.
Note: this is based on effective doses used in research.
This is equivalent to ~1 to 2 cups of coffee (but this estimate can be massively biased by coffee type and preparation method).
Taking more doesn’t necessarily mean a bigger effect; taking more increases the risk of side effects.
To conclude…
There’s lots of evidence to suggest that taking caffeine before a session or race is likely to boost your performance during endurance, strength, and speed-based events (click here to see some examples of caffeine-containing gels). The effect size ranges from small (for short, high/maximal-intensity efforts) to moderate/large (endurance tasks). During-exercise caffeine intake is also likely to boost your performance but there is insufficient knowledge to recommend a specific repeated caffeine dose regimen during exercise. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining caffeine for performance.
Here is the list of systematic reviews I have summarised above.
Acute Effects of Caffeine on Overall Performance in Basketball Players-A Systematic Review. Anja Lazić, Miodrag Kocić, Nebojša Trajković, Cristian Popa, Leonardo Alexandre Peyré-Tartaruga, Johnny Padulo. Nutrients (2022)
Effect of Pre-Exercise Caffeine Intake on Endurance Performance and Core Temperature Regulation During Exercise in the Heat: A Systematic Review with Meta-Analysis. Catherine Naulleau, David Jeker, Timothée Pancrate, Pascale Claveau, Thomas A Deshayes, Louise M Burke, Eric D B Goulet. Sports Med (2022)
Exploring the minimum ergogenic dose of caffeine on resistance exercise performance: A meta-analytic approach. Jozo Grgic. Nutr (2022)
Risk or benefit? Side effects of caffeine supplementation in sport: a systematic review. Jefferson Gomes de Souza, Juan Del Coso, Fabiano de Souza Fonseca, Bruno Victor Corrêa Silva, Diego Brito de Souza, Rodrigo Luiz da Silva Gianoni, Aleksandra Filip-Stachnik, Julio Cerca Serrão, João Gustavo Claudino. Eur J Nutr (2022)
Effects of acute caffeine intake on combat sports performance: A systematic review and meta-analysis. Javier Diaz-Lara, Jozo Grgic, Daniele Detanico, Javier Botella, Sergio L Jiménez, Juan Del Coso. Crit Rev Food Sci Nutr (2022)
Effects of caffeine on rate of force development: A meta-analysis. Jozo Grgic, Pavle Mikulic. Scand J Med Sci Sports (2022)
Supplementation and Performance for Wheelchair Athletes: A Systematic Review. Andreia Bauermann, Karina S G de Sá, Zilda A Santos, Anselmo A Costa E Silva. Adapt Phys Activ Q (2022)
Acute caffeine supplementation and live match-play performance in team-sports: A systematic review (2000-2021). Adriano Arguedas-Soley, Isobel Townsend, Aaron Hengist, James Betts. J Sports Sci (2022)
Interaction Between Caffeine and Creatine When Used as Concurrent Ergogenic Supplements: A Systematic Review. Sara Elosegui, Jaime López-Seoane, María Martínez-Ferrán, Helios Pareja-Galeano. Int J Sport Nutr Exerc Metab (2022)
Does Acute Caffeine Supplementation Improve Physical Performance in Female Team-Sport Athletes? Evidence from a Systematic Review and Meta-Analysis. Alejandro Gomez-Bruton, Jorge Marin-Puyalto, Borja Muñiz-Pardos, Angel Matute-Llorente, Juan Del Coso, Alba Gomez-Cabello, German Vicente-Rodriguez, Jose A Casajus, Gabriel Lozano-Berges. Nutrients (2021)
Caffeinated Drinks and Physical Performance in Sport: A Systematic Review. Sergio L Jiménez, Javier Díaz-Lara, Helios Pareja-Galeano, Juan Del Coso. Nutrients (2021)
Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis. Grgic J, Del Coso J. Int J Environ Res Public Health (2021)
Is caffeine mouth rinsing an effective strategy to improve physical and cognitive performance? A systematic review.
da Silva WF, Lopes-Silva JP, Camati Felippe LJ, Ferreira GA, Lima-Silva AE, Silva-Cavalcante MD. Crit Rev Food Sci Nutr (2021)
Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis. Grgic J, Del Coso J. Int J Environ Res Public Health (2021)
Caffeine and Cognitive Functions in Sports: A Systematic Review and Meta-Analysis. Lorenzo Calvo J, Fei X, Domínguez R, Pareja-Galeano H. Nutrients (2021)
Nonplacebo Controls to Determine the Magnitude of Ergogenic Interventions: A Systematic Review and Meta-analysis.
Marticorena FM, Carvalho A, de Oliveira LF, Dolan E, Gualano B, Swinton P, Saunders B. Med Sci Sports Exerc (2021)
CYP1A2 genotype and acute ergogenic effects of caffeine intake on exercise performance: a systematic review. Grgic J, Pickering C, Del Coso J, Schoenfeld BJ, Mikulic P. Eur J Nutr (2021)
Effects of diet interventions, dietary supplements, and performance-enhancing substances on the performance of CrossFit-trained individuals: A systematic review of clinical studies. Dos Santos Quaresma MVL, Guazzelli Marques C, Nakamoto FP. Nutrition (2021)
Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis. Collado-Mateo D, Lavín-Pérez AM, Merellano-Navarro E, Coso JD. Nutrients (2020)
Effect of Supplements on Endurance Exercise in the Older Population: Systematic Review. Martínez-Rodríguez A, Cuestas-Calero BJ, Hernández-García M, Martíez-Olcina M, Vicente-Martínez M, Rubio-Arias JÁ. Int J Environ Res Public Health (2020)
The Effects of Caffeine Mouth Rinsing on Exercise Performance: A Systematic Review. Ehlert AM, Twiddy HM, Wilson PB. Int J Sport Nutr Exerc Metab (2020)
Effects of caffeine supplementation on muscle endurance, maximum strength, and perceived exertion in adults submitted to strength training: a systematic review and meta-analyses. Ferreira TT, da Silva JVF, Bueno NB. Crit Rev Food Sci Nutr (2020)
Acute Effects of Caffeine Supplementation on Movement Velocity in Resistance Exercise: A Systematic Review and Meta-analysis. Raya-González J, Rendo-Urteaga T, Domínguez R, Castillo D, Rodríguez-Fernández A, Grgic J. Sports Med (2020)
The Effects of Caffeine Ingestion on Measures of Rowing Performance: A Systematic Review and Meta-Analysis. Grgic J, Diaz-Lara FJ, Coso JD, Duncan MJ, Tallis J, Pickering C, Schoenfeld BJ, Mikulic P. Nutrients (2020)
Is Caffeine Recommended Before Exercise? A Systematic Review To Investigate Its Impact On Cardiac Autonomic Control Via Heart Rate And Its Variability. Benjamim CJR, Kliszczewicz B, Garner DM, Cavalcante TCF, da Silva AAM, Santana MDR, Valenti VE. J Am Coll Nutr (2020)
Isolated effects of caffeine and sodium bicarbonate ingestion on performance in the Yo-Yo test: A systematic review and meta-analysis. Grgic J, Garofolini A, Pickering C, Duncan MJ, Tinsley GM, Del Coso J. J Sci Med Sport (2020)
Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses. Grgic J, Grgic I, Pickering C, Schoenfeld BJ, Bishop DJ, Pedisic Z. Br J Sports Med (2020)
The effects of caffeine ingestion on isokinetic muscular strength: A meta-analysis. Grgic J, Pickering C. J Sci Med Sport (2019)
Caffeine Supplementation and Physical Performance, Muscle Damage and Perception of Fatigue in Soccer Players: A Systematic Review. Mielgo-Ayuso J, Calleja-Gonzalez J, Del Coso J, Urdampilleta A, León-Guereño P, Fernández-Lázaro D. Nutrients (2019)
Effects of acute ingestion of caffeine on team sports performance: a systematic review and meta-analysis. Salinero JJ, Lara B, Del Coso J. Res Sports Med (2019)
Correction to: The Effect of Acute Caffeine Ingestion on Endurance Performance: A Systematic Review and Meta-Analysis. Southward K, Rutherfurd-Markwick KJ, Ali A. Sports Med (2018). Note: this article was originally published here but contained errors that were corrected in this revised version.
Effects of Coffee Components on Muscle Glycogen Recovery: A Systematic Review. Loureiro LMR, Reis CEG, da Costa THM. Int J Sport Nutr Exerc Metab (2018)
Caffeine and Physiological Responses to Submaximal Exercise: A Meta-Analysis. Glaister M, Gissane C. Int J Sports Physiol Perform (2018)
Caffeine ingestion enhances Wingate performance: a meta-analysis. Grgic J. Eur J Sport Sci (2018)
Acute effects of caffeine-containing energy drinks on physical performance: a systematic review and meta-analysis. Souza DB, Del Coso J, Casonatto J, Polito MD. Eur J Nutr (2017)
A systematic review of the efficacy of ergogenic aids for improving running performance. Schubert MM, Astorino TA. J Strength Cond Res (2013)
Does caffeine added to carbohydrate provide additional ergogenic benefit for endurance? Conger SA, Warren GL, Hardy MA, Millard-Stafford ML. Int J Sport Nutr Exerc Metab (2011)
Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: a systematic review. Astorino TA, Roberson DW. J Strength Cond Res (2010)
Effect of caffeine on sport-specific endurance performance: a systematic review. Ganio MS, Klau JF, Casa DJ, Armstrong LE, Maresh CM. J Strength Cond Res (2009)
Effects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis. Doherty M, Smith PM. Scand J Med Sci Sports (2005 )
Acute Effects of Caffeine on Overall Performance in Basketball Players-A Systematic Review. Anja Lazić, Miodrag Kocić, Nebojša Trajković, Cristian Popa, Leonardo Alexandre Peyré-Tartaruga, Johnny Padulo. Nutrients (2022) Effect of Pre-Exercise Caffeine Intake on Endurance Performance and Core Temperature Regulation During Exercise in the Heat: A Systematic Review with Meta-Analysis. Catherine Naulleau, David Jeker, Timothée Pancrate, Pascale Claveau, Thomas A Deshayes, Louise M Burke, Eric D B Goulet. Sports Med (2022) Exploring the minimum ergogenic dose of caffeine on resistance exercise performance: A meta-analytic approach. Jozo Grgic. Nutr (2022) Risk or benefit? Side effects of caffeine supplementation in sport: a systematic review. Jefferson Gomes de Souza, Juan Del Coso, Fabiano de Souza Fonseca, Bruno Victor Corrêa Silva, Diego Brito de Souza, Rodrigo Luiz da Silva Gianoni, Aleksandra Filip-Stachnik, Julio Cerca Serrão, João Gustavo Claudino. Eur J Nutr (2022) Effects of acute caffeine intake on combat sports performance: A systematic review and meta-analysis. Javier Diaz-Lara, Jozo Grgic, Daniele Detanico, Javier Botella, Sergio L Jiménez, Juan Del Coso. Crit Rev Food Sci Nutr (2022) Effects of caffeine on rate of force development: A meta-analysis. Jozo Grgic, Pavle Mikulic. Scand J Med Sci Sports (2022) Supplementation and Performance for Wheelchair Athletes: A Systematic Review. Andreia Bauermann, Karina S G de Sá, Zilda A Santos, Anselmo A Costa E Silva. Adapt Phys Activ Q (2022) Acute caffeine supplementation and live match-play performance in team-sports: A systematic review (2000-2021). Adriano Arguedas-Soley, Isobel Townsend, Aaron Hengist, James Betts. J Sports Sci (2022) Interaction Between Caffeine and Creatine When Used as Concurrent Ergogenic Supplements: A Systematic Review. Sara Elosegui, Jaime López-Seoane, María Martínez-Ferrán, Helios Pareja-Galeano. Int J Sport Nutr Exerc Metab (2022) Does Acute Caffeine Supplementation Improve Physical Performance in Female Team-Sport Athletes? Evidence from a Systematic Review and Meta-Analysis. Alejandro Gomez-Bruton, Jorge Marin-Puyalto, Borja Muñiz-Pardos, Angel Matute-Llorente, Juan Del Coso, Alba Gomez-Cabello, German Vicente-Rodriguez, Jose A Casajus, Gabriel Lozano-Berges. Nutrients (2021) Caffeinated Drinks and Physical Performance in Sport: A Systematic Review. Sergio L Jiménez, Javier Díaz-Lara, Helios Pareja-Galeano, Juan Del Coso. Nutrients (2021) Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis. Grgic J, Del Coso J. Int J Environ Res Public Health (2021) Is caffeine mouth rinsing an effective strategy to improve physical and cognitive performance? A systematic review.
da Silva WF, Lopes-Silva JP, Camati Felippe LJ, Ferreira GA, Lima-Silva AE, Silva-Cavalcante MD. Crit Rev Food Sci Nutr (2021) Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis. Grgic J, Del Coso J. Int J Environ Res Public Health (2021) Caffeine and Cognitive Functions in Sports: A Systematic Review and Meta-Analysis. Lorenzo Calvo J, Fei X, Domínguez R, Pareja-Galeano H. Nutrients (2021) Nonplacebo Controls to Determine the Magnitude of Ergogenic Interventions: A Systematic Review and Meta-analysis.
Marticorena FM, Carvalho A, de Oliveira LF, Dolan E, Gualano B, Swinton P, Saunders B. Med Sci Sports Exerc (2021) CYP1A2 genotype and acute ergogenic effects of caffeine intake on exercise performance: a systematic review. Grgic J, Pickering C, Del Coso J, Schoenfeld BJ, Mikulic P. Eur J Nutr (2021) Effects of diet interventions, dietary supplements, and performance-enhancing substances on the performance of CrossFit-trained individuals: A systematic review of clinical studies. Dos Santos Quaresma MVL, Guazzelli Marques C, Nakamoto FP. Nutrition (2021) Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis. Collado-Mateo D, Lavín-Pérez AM, Merellano-Navarro E, Coso JD. Nutrients (2020) Effect of Supplements on Endurance Exercise in the Older Population: Systematic Review. Martínez-Rodríguez A, Cuestas-Calero BJ, Hernández-García M, Martíez-Olcina M, Vicente-Martínez M, Rubio-Arias JÁ. Int J Environ Res Public Health (2020) The Effects of Caffeine Mouth Rinsing on Exercise Performance: A Systematic Review. Ehlert AM, Twiddy HM, Wilson PB. Int J Sport Nutr Exerc Metab (2020) Effects of caffeine supplementation on muscle endurance, maximum strength, and perceived exertion in adults submitted to strength training: a systematic review and meta-analyses. Ferreira TT, da Silva JVF, Bueno NB. Crit Rev Food Sci Nutr (2020) Acute Effects of Caffeine Supplementation on Movement Velocity in Resistance Exercise: A Systematic Review and Meta-analysis. Raya-González J, Rendo-Urteaga T, Domínguez R, Castillo D, Rodríguez-Fernández A, Grgic J. Sports Med (2020) The Effects of Caffeine Ingestion on Measures of Rowing Performance: A Systematic Review and Meta-Analysis. Grgic J, Diaz-Lara FJ, Coso JD, Duncan MJ, Tallis J, Pickering C, Schoenfeld BJ, Mikulic P. Nutrients (2020) Is Caffeine Recommended Before Exercise? A Systematic Review To Investigate Its Impact On Cardiac Autonomic Control Via Heart Rate And Its Variability. Benjamim CJR, Kliszczewicz B, Garner DM, Cavalcante TCF, da Silva AAM, Santana MDR, Valenti VE. J Am Coll Nutr (2020) Isolated effects of caffeine and sodium bicarbonate ingestion on performance in the Yo-Yo test: A systematic review and meta-analysis. Grgic J, Garofolini A, Pickering C, Duncan MJ, Tinsley GM, Del Coso J. J Sci Med Sport (2020) Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses. Grgic J, Grgic I, Pickering C, Schoenfeld BJ, Bishop DJ, Pedisic Z. Br J Sports Med (2020) The effects of caffeine ingestion on isokinetic muscular strength: A meta-analysis. Grgic J, Pickering C. J Sci Med Sport (2019) Caffeine Supplementation and Physical Performance, Muscle Damage and Perception of Fatigue in Soccer Players: A Systematic Review. Mielgo-Ayuso J, Calleja-Gonzalez J, Del Coso J, Urdampilleta A, León-Guereño P, Fernández-Lázaro D. Nutrients (2019) Effects of acute ingestion of caffeine on team sports performance: a systematic review and meta-analysis. Salinero JJ, Lara B, Del Coso J. Res Sports Med (2019) Correction to: The Effect of Acute Caffeine Ingestion on Endurance Performance: A Systematic Review and Meta-Analysis. Southward K, Rutherfurd-Markwick KJ, Ali A. Sports Med (2018). Note: this article was originally published here but contained errors that were corrected in this revised version. Effects of Coffee Components on Muscle Glycogen Recovery: A Systematic Review. Loureiro LMR, Reis CEG, da Costa THM. Int J Sport Nutr Exerc Metab (2018) Caffeine and Physiological Responses to Submaximal Exercise: A Meta-Analysis. Glaister M, Gissane C. Int J Sports Physiol Perform (2018) Caffeine ingestion enhances Wingate performance: a meta-analysis. Grgic J. Eur J Sport Sci (2018) Acute effects of caffeine-containing energy drinks on physical performance: a systematic review and meta-analysis. Souza DB, Del Coso J, Casonatto J, Polito MD. Eur J Nutr (2017) A systematic review of the efficacy of ergogenic aids for improving running performance. Schubert MM, Astorino TA. J Strength Cond Res (2013) Does caffeine added to carbohydrate provide additional ergogenic benefit for endurance? Conger SA, Warren GL, Hardy MA, Millard-Stafford ML. Int J Sport Nutr Exerc Metab (2011) Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: a systematic review. Astorino TA, Roberson DW. J Strength Cond Res (2010) Effect of caffeine on sport-specific endurance performance: a systematic review. Ganio MS, Klau JF, Casa DJ, Armstrong LE, Maresh CM. J Strength Cond Res (2009) Effects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis. Doherty M, Smith PM. Scand J Med Sci Sports (2005 )
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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Some amino acids are coded by our genes, some are used to build proteins; others are not. Taurine is an amino acid produced in the body from the metabolism of the amino acid, cysteine, but it is not used as a “building block” for protein synthesis. Instead, it interacts with ion channels to stabilize cell membrane integrity and regulate osmoregulation (water transport). Taurine is also essential for cardiac muscle and skeletal muscle function. See Lambert et al. 2014 to read all about the physiology of taurine from one of my former colleagues in Copenhagen.
Besides producing taurine in the body, we also obtain taurine in our diet, primarily from meat, dairy, seafood, and algae-containing food, like seaweed (see here and here). Because taurine regulates calcium homeostasis and can increase calcium-binding proteins during muscle contraction, it is alleged to play a role in muscle strength and endurance. Therefore, taurine is the stimulant of choice in many “energy” drinks (e.g. RedBull). But…
Does taurine improve performance — what do the systematic reviews say?
Taurine is generally safe to consume and energy drinks contain taurine in amounts far lower than levels that would cause adverse events (see here and here). Clinical studies use does of up to 3 to 10 grams per day and find that to be safe for human consumption. But, in the context of exercise performance, there is no evidence-informed recommended dose for taurine supplementation.
One systematic review found that pre-exercise taurine supplementation might have a small beneficial effect on improving time-to-exhaustion endurance performance (see Waldron et al. 2018) but these effects were most pronounced in patients with heart failure and less clear in healthy people or athletes. Furthermore, it is currently unclear whether people with inadequate dietary taurine intake are more likely to benefit from taurine supplementation — more research is needed.
A meta-analysis by Souza et al. 2017 found a positive relationship between increasing taurine dose and better performance improvement when energy drinks are supplemented before exercise. BUT the energy drinks also contained caffeine, so the independent effect of taurine in this relationship could not be resolved. Fortunately, the meta-analysis by Waldron et al. 2018 specifically examined the dose-dependent effects of taurine, finding no relationship between increasing taurine dose and changes in performance.
Overall, the current quality of evidence is poor, high-quality dose-response studies are lacking, and high-quality randomised controlled trials are urgently needed.
To conclude…
The current evidence suggests that taurine is unlikely to boost your performance. Due to the low quality of existing clinical studies, the effect size is unclear. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining taurine for performance.
Here is the list of systematic reviews I have summarised above.
The Dose Response of Taurine on Aerobic and Strength Exercises: A Systematic Review. Chen Q, Li Z, Pinho RA, Gupta RC, Ugbolue UC, Thirupathi A, Gu Y. Front Physiol (2021).
The Effects of an Oral Taurine Dose and Supplementation Period on Endurance Exercise Performance in Humans: A Meta-Analysis. Mark Waldron, Stephen David Patterson, Jamie Tallent, Owen Jeffries. Sports Med (2018)
Acute effects of caffeine-containing energy drinks on physical performance: a systematic review and meta-analysis. Diego B Souza, Juan Del Coso, Juliano Casonatto, Marcos D Polito. Eur J Nutr (2017)
The Dose Response of Taurine on Aerobic and Strength Exercises: A Systematic Review. Chen Q, Li Z, Pinho RA, Gupta RC, Ugbolue UC, Thirupathi A, Gu Y. Front Physiol (2021).
The Effects of an Oral Taurine Dose and Supplementation Period on Endurance Exercise Performance in Humans: A Meta-Analysis. Mark Waldron, Stephen David Patterson, Jamie Tallent, Owen Jeffries. Sports Med (2018)
Acute effects of caffeine-containing energy drinks on physical performance: a systematic review and meta-analysis. Diego B Souza, Juan Del Coso, Juliano Casonatto, Marcos D Polito. Eur J Nutr (2017)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
This tool is free. Please help keep it alive by buying me a beer:
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Some amino acids are coded by our genes, some are used to build proteins; others are not. Creatine is a naturally occurring amino acid derivative but, unlike standard amino acids, it is not coded by our genes and it is not a protein building block. Instead, creatine is involved in energy metabolism. In humans, the vast majority (~95%) of creatine is found in our muscles. Our body can synthesise creatine from the amino acids, arginine and glycine, but because creatine is also degraded to creatinine and then excreted in our urine, we must also consume creatine in our diet to maintain adequate bodily levels. This can be achieved by eating meat (inc. red meat, chicken, pork, etc), fish (e.g. salmon) and seafood.
ATP hydrolysis: ATP → ADP + Pi + H+
ATP resynthesis: PCr → Cr + Pi then ADP + Pi → ATP
So, by having adequate muscle levels of creatine, you have the opportunity to produce phosphocreatine. Therefore, the creatine in your muscles helps maintain ATP availability for maximal-effort, anaerobic/sprint-type exercise. Since daily creatine supplementation increases its levels in your muscles, creatine has become a very popular supplement. So…
ATP resynthesis: PCr → Cr + Pi then ADP + Pi → ATP
Does creatine improve performance — what do the systematic reviews say?
Creatine supplementation is safe for most people. That said, folks with asthma, immune dysfunction, and/or kidney or liver conditions, should consult their doctor before considering a creatine supplement.
Creatine supplementation does not improve training-induced gains in endurance performance (including aerobic performance tests like time trials and time-to-exhaustion tests). In fact, one meta-analysis finds that creatine can blunt training-induced improvements in V̇O2max (small effect size).
Creatine supplementation improves training-induced gains in lower-body and upper-body maximal strength and reps-to-failure taking less than ~3-mins (small to moderate effect size).
Creatine supplementation improves training-induced gains in high-intensity “anaerobic” performance (e.g. 30-second Wingate sprint tests; large effect size).
Combining creatine supplementation with strength training in older adults (60+ years old) is also more effective for maintaining muscle mass (large effect size), muscle strength (small to moderate effect size), and functional ability (e.g. chair sit-to-stand task; large effect size) than strength training alone. This suggests that creatine might be a useful “add-on” for healthy ageing.
Some evidence finds an increased incidence of gastrointestinal distress in folks who concurrently supplement with creatine and caffeine and that chronic caffeine supplementation during a creatine loading phase might blunt the beneficial effect of creatine while creatine loading does not seem to interfere in the acute effect of caffeine. However, more high-quality randomised controlled trials are needed to clarify caffeine-creatine interactions.
Since creatine is found in meat and since plant-based eaters exclude meat from their diet, muscle creatine levels might to be lower in plant-based diet eaters than in meat-eating folk. Fortunately, creatine supplementation in plant-based eaters increases muscle creatine levels and improves high-intensity “anaerobic” performance in the same way as it does for meat-eaters. But, if you follow a plant-based diet, you may also wonder how to supplement with creatine when it is found in meat. Fear not, creatine in creatine supplements is chemically synthesised rather than extracted from meat (the only thing a plant-based eater might need to check is whether the supplement capsule is plant-based).
If you choose to use creatine, a reasonable dose that increases muscle levels of creatine is:
A “loading dose” of 5 grams of creatine monohydrate 4-times per day for 5 to 7 days followed by a “maintenance dose” of 3 to 5 grams per day. Note: this is based on effective doses used in research studies that increase muscle levels of creatine and improve performance.
An alternative but slower “non-loading” approach is to ingest 3 g/day of creatine monohydrate for 28-days. Note: this is based on effective doses used in research.
Taking more doesn’t necessarily mean a bigger effect but some studies show that larger athletes may need to ingest as much as 5–10 g/day to maintain creatine stores.
When supplementation is stopped, it takes approx 4 to 6-weeks for elevated muscle creatine levels to return to baseline levels.
To conclude…
There is lots of evidence to suggest that taking a daily creatine supplement is likely to boost your performance during maximal strength, reps-to-failure, or maximal speed-based events (lasting up to ~30 seconds). The effect size is moderate to large. Creatine supplementation will not improve your endurance performance — it may even blunt training-induced gains in V̇O2max. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining creatine for performance.
Here is the list of systematic reviews I have summarised above.
The Paradoxical Effect of Creatine Monohydrate on Muscle Damage Markers: A Systematic Review and Meta-Analysis. Kenji Doma, Akhilesh Kumar Ramachandran, Daniel Boullosa & Jonathan Connor. Sports Med (2022)
Interaction Between Caffeine and Creatine When Used as Concurrent Ergogenic Supplements: A Systematic Review. Sara Elosegui, Jaime López-Seoane, María Martínez-Ferrán, Helios Pareja-Galeano. Int J Sport Nutr Exerc Metab (2022)
Effects of creatine and caffeine ingestion in combination on exercise performance: A systematic review. Alisson H Marinho, Jaqueline S Gonçalves, Palloma K Araújo, Adriano E Lima-Silva, Thays Ataide-Silva, Gustavo G de Araujo. Crit Rev Food Sci Nutr (2021)
Creatine supplementation and VO2 max: a systematic review and meta-analysis. Damien Gras, Charlotte Lanhers, Reza Bagheri, Fred Dutheil. Crit Rev Food Sci Nutr (2021)
The Effect of Creatine Supplementation on Markers of Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis of Human Intervention Trials. Northeast B, Clifford T. Int J Sport Nutr Exerc Metab (2021)
Benefits of Creatine Supplementation for Vegetarians Compared to Omnivorous Athletes: A Systematic Review. Kaviani M, Shaw K, Chilibeck PD. Int J Environ Res Public Health (2020)
The Additive Effects of Creatine Supplementation and Exercise Training in an Aging Population: A Systematic Review of Randomized Controlled Trials. Stares A, Bains M. J Geriatr Phys Ther (2020)
Effect of the Combination of Creatine Monohydrate Plus HMB Supplementation on Sports Performance, Body Composition, Markers of Muscle Damage and Hormone Status: A Systematic Review. Fernández-Landa J, Calleja-González J, León-Guereño P, Caballero-García A, Córdova A, Mielgo-Ayuso J. Nutrients (2019)
Effects of Creatine Supplementation on Athletic Performance in Soccer Players: A Systematic Review and Meta-Analysis. Mielgo-Ayuso J, Calleja-Gonzalez J, Marqués-Jiménez D, Caballero-García A, Córdova A, Fernández-Lázaro D. Nutrients (2019)
Creatine Supplementation and Upper Limb Strength Performance: A Systematic Review and Meta-Analysis. Lanhers C, Pereira B, Naughton G, Trousselard M, Lesage FX, Dutheil F. Sports Med (2017)
Creatine Supplementation and Lower Limb Strength Performance: A Systematic Review and Meta-Analyses. Lanhers C, Pereira B, Naughton G, Trousselard M, Lesage FX, Dutheil F. Sports Med (2015)
Creatine supplementation and aging musculoskeletal health. Candow DG, Chilibeck PD, Forbes SC. Endocrine (2014)
Creatine supplementation during resistance training in older adults-a meta-analysis. Devries MC, Phillips SM. Med Sci Sports Exerc (2014)
Effect of creatine supplementation on body composition and performance: a meta-analysis. Branch JD. Int J Sport Nutr Exerc Metab (2003)
Does oral creatine supplementation improve strength? A meta-analysis. Dempsey RL, Mazzone MF, Meurer LN. J Fam Pract (2002)
Creatine supplementation as an ergogenic aid for sports performance in highly trained athletes: a critical review. Mujika I, Padilla S. Int J Sports Med (1997)
The Paradoxical Effect of Creatine Monohydrate on Muscle Damage Markers: A Systematic Review and Meta-Analysis. Kenji Doma, Akhilesh Kumar Ramachandran, Daniel Boullosa & Jonathan Connor. Sports Med (2022)
Interaction Between Caffeine and Creatine When Used as Concurrent Ergogenic Supplements: A Systematic Review. Sara Elosegui, Jaime López-Seoane, María Martínez-Ferrán, Helios Pareja-Galeano. Int J Sport Nutr Exerc Metab (2022)
Effects of creatine and caffeine ingestion in combination on exercise performance: A systematic review. Alisson H Marinho, Jaqueline S Gonçalves, Palloma K Araújo, Adriano E Lima-Silva, Thays Ataide-Silva, Gustavo G de Araujo. Crit Rev Food Sci Nutr (2021)
Creatine supplementation and VO2 max: a systematic review and meta-analysis. Damien Gras, Charlotte Lanhers, Reza Bagheri, Fred Dutheil. Crit Rev Food Sci Nutr (2021) The Effect of Creatine Supplementation on Markers of Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis of Human Intervention Trials. Northeast B, Clifford T. Int J Sport Nutr Exerc Metab (2021) Benefits of Creatine Supplementation for Vegetarians Compared to Omnivorous Athletes: A Systematic Review. Kaviani M, Shaw K, Chilibeck PD. Int J Environ Res Public Health (2020) The Additive Effects of Creatine Supplementation and Exercise Training in an Aging Population: A Systematic Review of Randomized Controlled Trials. Stares A, Bains M. J Geriatr Phys Ther (2020) Effect of the Combination of Creatine Monohydrate Plus HMB Supplementation on Sports Performance, Body Composition, Markers of Muscle Damage and Hormone Status: A Systematic Review. Fernández-Landa J, Calleja-González J, León-Guereño P, Caballero-García A, Córdova A, Mielgo-Ayuso J. Nutrients (2019) Effects of Creatine Supplementation on Athletic Performance in Soccer Players: A Systematic Review and Meta-Analysis. Mielgo-Ayuso J, Calleja-Gonzalez J, Marqués-Jiménez D, Caballero-García A, Córdova A, Fernández-Lázaro D. Nutrients (2019) Creatine Supplementation and Upper Limb Strength Performance: A Systematic Review and Meta-Analysis. Lanhers C, Pereira B, Naughton G, Trousselard M, Lesage FX, Dutheil F. Sports Med (2017) Creatine Supplementation and Lower Limb Strength Performance: A Systematic Review and Meta-Analyses. Lanhers C, Pereira B, Naughton G, Trousselard M, Lesage FX, Dutheil F. Sports Med (2015) Creatine supplementation and aging musculoskeletal health. Candow DG, Chilibeck PD, Forbes SC. Endocrine (2014) Creatine supplementation during resistance training in older adults-a meta-analysis. Devries MC, Phillips SM. Med Sci Sports Exerc (2014) Effect of creatine supplementation on body composition and performance: a meta-analysis. Branch JD. Int J Sport Nutr Exerc Metab (2003) Does oral creatine supplementation improve strength? A meta-analysis. Dempsey RL, Mazzone MF, Meurer LN. J Fam Pract (2002) Creatine supplementation as an ergogenic aid for sports performance in highly trained athletes: a critical review. Mujika I, Padilla S. Int J Sports Med (1997)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
This tool is free. Please help keep it alive by buying me a beer:
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Nitrate (NO3-) is a naturally occurring ion found in high amounts in leafy green veg, like spinach, and in beetroot, which is the food that has been popularised when talking “nitrate”. When we ingest nitrate or nitrate-containing foods, nitrate (NO3-) is converted to nitrite (NO2-). Nitrite is then absorbed in the intestine into the blood and metabolised to produce nitric oxide (NO) via several different enzymatic pathways. And, nitric oxide is important because it plays a major role in the regulation of vascular (it increases blood flow and vasodilation, which may enhance the delivery of oxygen and energy substrates to muscles) and metabolic (mitochondrial) function. But, it has a very short half-life in the body — when nitric oxide is produced, it acts rapidly and is used very quickly.
But, it’s little more complicated than than because we have no biological machinary to reduce nitrate (NO3-) to nitrite (NO2-) and rely on bacteria in our mouth for this part of the process (these bacteria use an enzyme called nitrate reductase to provide an electron and a proton to catalyse this reaction):
NO3- + e- + H+ → NO2- + H2O
Nitrate + an Electron + a Proton → Nitrite + Water
Interestingly, since it is the bacteria in your mouth that convert nitrate to nitrite allowing your biology to produce nitric oxide (NO), an alcohol-based mouthwash can prevent you producing nitrite (and, therefore, nitric oxide) after eating nitrate (see here & here)… Oh NO.
Nitrate + an Electron + a Proton → Nitrite + Water
Nitric oxide can be synthesised in our body from the amino acid, L-arginine, by nitric oxide synthase (NOS) enzymes. So, dietary intake of nitrate provides an additional source of nitric oxide on top of what our nitric oxide synthase pathways can produce. Since nitric oxide regulates blood flow and mitochondrial function, you can see why ingesting nitrate or nitrate-containing foods may be of interest to an athlete. But, nitrate (or beetroot) is certainly one of those compounds for which it is easy to head to PubMed and cherry-pick a paper showing that it is or is not beneficial for sports performance. So…
Does nitrate (or beetroot) improve performance — what do the systematic reviews say?
Nitrate is generally safe to consume but can cause gastrointestinal issues in some folks. Also, note that beetroot juice may turn your urine red/purple — this is normal. Effects on Strength and power:
Single-dose (acute) nitrate supplementation with beetroot juice before exercise increases maximal power during sprinting (small effect size) and increases maximal force during maximal voluntary contractions (small effect size). Multiple-day (chronic) dosing might reduce this effect to a trivial effect size (i.e. no effect).
Single dose (acute) nitrate supplementation with beetroot juice before exercise increases muscular endurance during isolated muscle isokinetic contractions to failure (small effect size).
These benefits of (acute) nitrate supplementation on muscle strength and muscle endurance may extend to improved weightlifting performance but currently only 4 such studies confirm that effect. Effects on Endurance:
Acute nitrate supplementation decreases oxygen consumption (V̇O2) during exercise without a change in maximal and/or mean (average) power output, suggesting that nitrate supplementation reduces the energy cost of exercise and, therefore, improves economy/efficiency. Consequently, there is potential for an effect of nitrate supplementation on endurance performance. But…
The effect of acute nitrate supplementation (primarily using beetroot juice) on endurance performance is a tricky one. When all exercise tests assessing performance and capacity are pooled (time-to-exhaustion, time-trial, average power, and V̇O2max, etc), the effect size is trivial and the variability among studies is very large. When the types of exercise test are stratified, there is a small beneficial effect of acute nitrate supplementation on time-to-exhaustion tasks (exercise capacity at fixed intensity until fatigue) but no effect on time-trial performance (trivial effect size). There is also no effect of nitrate supplementation on repeated high-intensity efforts during prolonged endurance exercise or performance measures during high-intensity interval training or sprint interval training.
Nitrate-containing foods have also been examined — there is no effect of acute (single dose) or chronic (long-term daily doses) of nitrate-containing foods (inc. beetroot, red spinach, Swiss chard, and rhubarb) on endurance time-trial performance or time-to-exhaustion tests.
So, nitrate supplementation might enhance economy and endurance capacity (exercise at a low-to-moderate intensity until failure) but nitrate supplementation does not enhance endurance time-trial performance (time to complete a distance). All that said, there are also several nuances in this field:
The optimal nitrate dose, the optimal duration of nitrate dose (how many consecutive days should you take it), and the optimal time-course of nitrate dose (how long before exercise should you take it) cannot yet be resolved from the literature — more work is needed.
Two systematic reviews (here & here) have specifically examined whether training status influence the effects of nitrate supplement and other systematic reviews have explored this using sub-analyses. The beneficial effect of nitrate supplementation on endurance exercise capacity is most robust in recreational level athletes — the performance-enhancing effect of nitrate supplementation is blunted (and mostly non-existent) in highly-trained folks (especially those with V̇O2max ≥65 mL/kg/min). Importantly, however, nitrate supplementation does not appear to harm performance.
Studies have predominantly studied males. The effect of nitrates or nitrate-containing foods on performance in females is trivial but more work is needed.
Several systematic reviews report large variations in exercise protocols, nitrate dosage, type of beetroot product, supplementation strategy, and supplementation duration among studies. And, due to a lack of thorough experimental details, several systematic reviews report an unclear risk of bias. Therefore, concrete conclusions are difficult.
If you choose to use nitrate/beetroot, a reasonable dose is:
300 to 600 milligrams (0.3 to 0.6 grams) about 2 to 3-hours before exercise. Note: this is based on effective doses used in research.
This is typically achieved by taking a sodium nitrate supplement, beetroot extract, or beetroot juice.
Taking more doesn’t necessarily mean a bigger effect. Taking more can also increase gastrointestinal issues.
To conclude…
The evidence suggests that taking a sodium nitrate or beetroot supplement before exercise is likely to boost your performance during strength, power, and speed-based events but the effect size is small. Meanwhile, taking a sodium nitrate or beetroot supplement before exercise is also likely to improve endurance exercise capacity (time-to-exhaustion) but not time trial performance. The effect size is also small and typically only evident in recreational level athletes — the endurance-enhancing effect is blunted in highly-trained endurance athletes. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining nitrate and beetroot for performance.
Here is the list of systematic reviews I have summarised above.
The Effect of Dietary Nitrate on the Contractile Properties of Human Skeletal Muscle: A Systematic Review and Meta-Analysis. Ozcan Esen, Nick Dobbin, Michael J Callaghan. J Am Nutr Assoc (2022)
The Effects of Dietary Nitrate Supplementation on Explosive Exercise Performance: A Systematic Review. Rachel Tan,Leire Cano, Ángel Lago-Rodríguez and Raúl Domínguez. Int J Environ Res Public Health (2022)
The Effect of Beetroot Ingestion on High-Intensity Interval Training: A Systematic Review and Meta-Analysis. Tak Hiong Wong, Alexiaa Sim, Stephen F Burns. Nutrients (2021)
Effect of food sources of nitrate, polyphenols, L-arginine and L-citrulline on endurance exercise performance: a systematic review and meta-analysis of randomised controlled trials. Noah M. A. d’Unienville, Henry T. Blake, Alison M. Coates, Alison M. Hill, Maximillian J. Nelson & Jonathan D. Buckley. J Int Soc Sports Nutr (2021)
Effect of dietary nitrate on human muscle power: a systematic review and individual participant data meta-analysis. Coggan AR, Baranauskas MN, Hinrichs RJ, Liu Z, Carter SJ. J Int Soc Sports Nutr (2021)
Effects of Beetroot Supplementation on Recovery After Exercise-Induced Muscle Damage: A Systematic Review. Rojano-Ortega D, Peña Amaro J, Berral-Aguilar AJ, Berral-de la Rosa FJ. Sports Health (2021)
The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis. Gao C, Gupta S, Adli T, Hou W, Coolsaet R, Hayes A, Kim K, Pandey A, Gordon J, Chahil G, Belley-Cote EP, Whitlock RP. J Int Soc Sports Nutr (2021)
The Effect of Nitrate-Rich Beetroot Juice on Markers of Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis of Human Intervention Trials. Jones L, Bailey SJ, Rowland SN, Alsharif N, Shannon OM, Clifford T. < J Diet Suppl (2021)
Effect of dietary nitrate ingestion on muscular performance: a systematic review and meta-analysis of randomized controlled trials. Alvares TS, Oliveira GV, Volino-Souza M, Conte-Junior CA, Murias JM. Crit Rev Food Sci Nutr (2021)
Ergogenic potential of foods for performance and recovery: a new alternative in sports supplementation? A systematic review. Costa MS, Toscano LT, Toscano LLT, Luna VR, Torres RA, Silva JA, Silva AS. Crit Rev Food Sci Nutr (2020)
The Effect of Dietary Nitrate Supplementation on Isokinetic Torque in Adults: A Systematic Review and Meta-Analysis.. Lago-Rodríguez Á, Domínguez R, Ramos-Álvarez JJ, Tobal FM, Jodra P, Tan R, Bailey SJ. Nutrients (2020)
Ergogenic Effect of Nitrate Supplementation: A Systematic Review and Meta-analysis. Senefeld JW, Wiggins CC, Regimbal RJ, Dominelli PB, Baker SE, Joyner MJ. Med Sci Sports Exerc (2020)
Nutritional Ergogenic Aids in Racquet Sports: A Systematic Review. Vicente-Salar N, Santos-Sánchez G, Roche E. Nutrients (2020)
Effects of Dietary Nitrates on Time Trial Performance in Athletes with Different Training Status: Systematic Review. Hlinský T, Kumstát M, Vajda P. Nutrients (2020)
Effects of diet interventions, dietary supplements, and performance-enhancing substances on the performance of CrossFit-trained individuals: A systematic review of clinical studies. Dos Santos Quaresma MVL, Guazzelli Marques C, Nakamoto FP. Nutrition (2021)
Effects of Dietary Nitrate Supplementation on Weightlifting Exercise Performance in Healthy Adults: A Systematic Review. San Juan AF, Dominguez R, Lago-Rodríguez Á, Montoya JJ, Tan R, Bailey SJ. Nutriients (2020)
Effectiveness of beetroot juice derived nitrates supplementation on fatigue resistance during repeated-sprints: a systematic review. Rojas-Valverde D, Montoya-Rodríguez J, Azofeifa-Mora C, Sanchez-Urena B. Crit Rev Food Sci Nutr (2020)
Influence of Nitrate Supplementation on Endurance Cyclic Sports Performance: A Systematic Review. Lorenzo Calvo J, Alorda-Capo F, Pareja-Galeano H, Jiménez SL. Nutrients (2020)
Nutritional Strategies to Optimize Performance and Recovery in Rowing Athletes. Kim J, Kim EK. Nutrients (2020)
The Effect of Nitrate Supplementation on Exercise Tolerance and Performance: A Systematic Review and Meta-Analysis. Van De Walle GP, Vukovich MD. J Strength Cond Res (2018)
Nitrate supplementation improves physical performance specifically in non-athletes during prolonged open-ended tests: a systematic review and meta-analysis. Campos HO, Drummond LR, Rodrigues QT, Machado FSM, Pires W, Wanner SP, Coimbra CC. Br J Nutr (2018)
Performance and Health Benefits of Dietary Nitrate Supplementation in Older Adults: A Systematic Review. Stanaway L, Rutherfurd-Markwick K, Page R, Ali A. Nutrients (2017)
The Effect of Dietary Nitrate Supplementation on Endurance Exercise Performance in Healthy Adults: A Systematic Review and Meta-Analysis. McMahon NF, Leveritt MD, Pavey TG. Sports Med (2017)
Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review. Domínguez R, Cuenca E, Maté-Muñoz JL, García-Fernández P, Serra-Paya N, Estevan MC, Herreros PV, Garnacho-Castaño MV. Nutrients (2017)
The effect of nitrate supplementation on exercise performance in healthy individuals: a systematic review and meta-analysis. Hoon MW, Johnson NA, Chapman PG, Burke LM. Int J Sport Nutr Exerc Metab (2013)
The Effect of Dietary Nitrate on the Contractile Properties of Human Skeletal Muscle: A Systematic Review and Meta-Analysis. Ozcan Esen, Nick Dobbin, Michael J Callaghan. J Am Nutr Assoc (2022) The Effects of Dietary Nitrate Supplementation on Explosive Exercise Performance: A Systematic Review. Rachel Tan,Leire Cano, Ángel Lago-Rodríguez and Raúl Domínguez. Int J Environ Res Public Health (2022) The Effect of Beetroot Ingestion on High-Intensity Interval Training: A Systematic Review and Meta-Analysis. Tak Hiong Wong, Alexiaa Sim, Stephen F Burns. Nutrients (2021) Effect of food sources of nitrate, polyphenols, L-arginine and L-citrulline on endurance exercise performance: a systematic review and meta-analysis of randomised controlled trials. Noah M. A. d’Unienville, Henry T. Blake, Alison M. Coates, Alison M. Hill, Maximillian J. Nelson & Jonathan D. Buckley. J Int Soc Sports Nutr (2021) Effect of dietary nitrate on human muscle power: a systematic review and individual participant data meta-analysis. Coggan AR, Baranauskas MN, Hinrichs RJ, Liu Z, Carter SJ. J Int Soc Sports Nutr (2021) Effects of Beetroot Supplementation on Recovery After Exercise-Induced Muscle Damage: A Systematic Review. Rojano-Ortega D, Peña Amaro J, Berral-Aguilar AJ, Berral-de la Rosa FJ. Sports Health (2021) The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis. Gao C, Gupta S, Adli T, Hou W, Coolsaet R, Hayes A, Kim K, Pandey A, Gordon J, Chahil G, Belley-Cote EP, Whitlock RP. J Int Soc Sports Nutr (2021) The Effect of Nitrate-Rich Beetroot Juice on Markers of Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis of Human Intervention Trials. Jones L, Bailey SJ, Rowland SN, Alsharif N, Shannon OM, Clifford T. < J Diet Suppl (2021) Effect of dietary nitrate ingestion on muscular performance: a systematic review and meta-analysis of randomized controlled trials. Alvares TS, Oliveira GV, Volino-Souza M, Conte-Junior CA, Murias JM. Crit Rev Food Sci Nutr (2021) Ergogenic potential of foods for performance and recovery: a new alternative in sports supplementation? A systematic review. Costa MS, Toscano LT, Toscano LLT, Luna VR, Torres RA, Silva JA, Silva AS. Crit Rev Food Sci Nutr (2020) The Effect of Dietary Nitrate Supplementation on Isokinetic Torque in Adults: A Systematic Review and Meta-Analysis.. Lago-Rodríguez Á, Domínguez R, Ramos-Álvarez JJ, Tobal FM, Jodra P, Tan R, Bailey SJ. Nutrients (2020) Ergogenic Effect of Nitrate Supplementation: A Systematic Review and Meta-analysis. Senefeld JW, Wiggins CC, Regimbal RJ, Dominelli PB, Baker SE, Joyner MJ. Med Sci Sports Exerc (2020) Nutritional Ergogenic Aids in Racquet Sports: A Systematic Review. Vicente-Salar N, Santos-Sánchez G, Roche E. Nutrients (2020) Effects of Dietary Nitrates on Time Trial Performance in Athletes with Different Training Status: Systematic Review. Hlinský T, Kumstát M, Vajda P. Nutrients (2020) Effects of diet interventions, dietary supplements, and performance-enhancing substances on the performance of CrossFit-trained individuals: A systematic review of clinical studies. Dos Santos Quaresma MVL, Guazzelli Marques C, Nakamoto FP. Nutrition (2021) Effects of Dietary Nitrate Supplementation on Weightlifting Exercise Performance in Healthy Adults: A Systematic Review. San Juan AF, Dominguez R, Lago-Rodríguez Á, Montoya JJ, Tan R, Bailey SJ. Nutriients (2020) Effectiveness of beetroot juice derived nitrates supplementation on fatigue resistance during repeated-sprints: a systematic review. Rojas-Valverde D, Montoya-Rodríguez J, Azofeifa-Mora C, Sanchez-Urena B. Crit Rev Food Sci Nutr (2020) Influence of Nitrate Supplementation on Endurance Cyclic Sports Performance: A Systematic Review. Lorenzo Calvo J, Alorda-Capo F, Pareja-Galeano H, Jiménez SL. Nutrients (2020) Nutritional Strategies to Optimize Performance and Recovery in Rowing Athletes. Kim J, Kim EK. Nutrients (2020) The Effect of Nitrate Supplementation on Exercise Tolerance and Performance: A Systematic Review and Meta-Analysis. Van De Walle GP, Vukovich MD. J Strength Cond Res (2018) Nitrate supplementation improves physical performance specifically in non-athletes during prolonged open-ended tests: a systematic review and meta-analysis. Campos HO, Drummond LR, Rodrigues QT, Machado FSM, Pires W, Wanner SP, Coimbra CC. Br J Nutr (2018) Performance and Health Benefits of Dietary Nitrate Supplementation in Older Adults: A Systematic Review. Stanaway L, Rutherfurd-Markwick K, Page R, Ali A. Nutrients (2017) The Effect of Dietary Nitrate Supplementation on Endurance Exercise Performance in Healthy Adults: A Systematic Review and Meta-Analysis. McMahon NF, Leveritt MD, Pavey TG. Sports Med (2017) Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review. Domínguez R, Cuenca E, Maté-Muñoz JL, García-Fernández P, Serra-Paya N, Estevan MC, Herreros PV, Garnacho-Castaño MV. Nutrients (2017) The effect of nitrate supplementation on exercise performance in healthy individuals: a systematic review and meta-analysis. Hoon MW, Johnson NA, Chapman PG, Burke LM. Int J Sport Nutr Exerc Metab (2013)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
This tool is free. Please help keep it alive by buying me a beer:
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Some amino acids are coded by our genes, some are used to build proteins; others are not. Citrulline is an amino acid that is not coded by our genes and is not a protein building block but it is a “nonessential” amino acid (i.e. our body can synthesise it and we don’t need to consume it). Citrulline is an intermediate metabolite of the urea cycle produced in the mitochondria of the liver (see here for description of urea cycle and a diagram here). Citrulline is also synthesised from arginine by the enzyme, nitric oxide synthase, during nitric oxide (NO) production.
2 L-arginine + 3 NADPH + 3 H+ + 4 O2 ⇌ 2 L-citrulline + 2 nitric oxide + 4 H2O + 3 NADP+
Although our bodies naturally produce citrulline, consuming citrulline or citrulline-containing foods increases our citrulline levels. Citrulline is found in high amounts in watermelon, therefore citrulline-containing supplements include watermelon juice but also pure L-citrulline and citrulline malate. Malate is an intermediate metabolite of the tricarboxylic acid (TCA) cycle (a process that helps you produce ATP in the mitochondria). Therefore, supplement Lords believe malate will increase ATP production. Whether this is true is currently unknown and the effect of citrulline malate vs. L-citrulline is also not known.
In the context of exercise, the mechanistic effects of citrulline are not well understood. Based on cell studies, animal studies, and some human data, citrulline is thought to increase levels of nitric oxide (NO), a molecule that regulates mitochondrial and vascular function (increased blood flow and vasodilation to enhance the delivery of oxygen) with rapid but very short-lived effects. Meanwhile, due to its role in the urea cycle, citrulline may also improve the clearance of ammonia (which can accumulate in muscle during intense exercise and cause fatigue). Whether such potential mechanisms extrapolate to an improvement in performance is why I am writing this. So…
Does Citrulline (or watermelon juice or citrulline malate) improve performance — what do the systematic reviews say?
L-citrulline is generally safe to consume.
Supplementation with L-citrulline (watermelon juice) or citrulline malate increases performance of high intensity strength and power tasks, including weightlifting 1RM & peak force, and cycling sprint peak power (borderline trivial-small effect size).
Supplementation with L-citrulline (watermelon juice) or citrulline malate increases the number of weighted reps (small effect size) and reps-to-failure during strength exercise (borderline trivial-small effect size).
Supplementation with L-citrulline or watermelon juice does not improve V̇O2max, time-to-exhaustion, or time-trial performance (trivial effect size). Therefore, citrulline is not likely to improve endurance performance. Note: there is not yet sufficient data on citrulline malate for a meta-analysis.
I bloody love watermelon, and always feel pretty epic riding home from the grocery store with a massive one in my pannier bag. But, I’ve never tried a citrulline supplement or citrulline malate. Folks who have, tell me it has a sour taste, which means it is might be your yin to the yang of a sweet sugary drink.
Given the above-described theoretical effect of citrulline, evidence supporting citrulline-induced improvements in vasodilation and skeletal muscle tissue perfusion is scarce and inconsistent.
It is unclear whether the addition of malate (i.e. citrulline malate) is necessary. Despite that, most studies use a citrulline malate supplement given ~60-mins before exercise at a dose of ~8 grams per day, on average (6 to 12 g/d range).
Overall, the current body of evidence is small, the acute vs. chronic effects are not well defined, there is a lack of clarity about the necessity of malate, and the heterogeneity of dose/duration among studies make firm conclusions difficult.
If you choose to use citrulline / watermelon juice / citrulline malate, a reasonable dose is:
~3 grams of L-citrulline (or ~8 grams citrulline malate) approx 60-mins before exercise. Note: this is the current minimal effective doses used in research.
Daily dosing for more than 7-days might have a greater effect than a single pre-exercise dose.
This is equivalent to eating ~7.5 to 105 kilograms of watermelon per day, which is clearly not feasible (Note: the citrulline content of watermelon ranges from 3.9 to 28.5 mg/g dry weight)
Taking more doesn’t necessarily mean a bigger effect.
To conclude…
There is some evidence to suggest that taking citrulline / watermelon juice / citrulline malate before a strength session is likely to boost your performance. The effect size is borderline trivial-small. Meanwhile, citrulline / watermelon / citrulline malate are highly unlikely to boost your endurance performance. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining citrulline (malate) and watermelon for performance.
Here is the list of systematic reviews I have summarised above.
Effect of food sources of nitrate, polyphenols, L-arginine and L-citrulline on endurance exercise performance: a systematic review and meta-analysis of randomised controlled trials. Noah M. A. d’Unienville, Henry T. Blake, Alison M. Coates, Alison M. Hill, Maximillian J. Nelson & Jonathan D. Buckley. J Int Soc Sports Nutr (2021)
Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis. Vårvik FT, Bjørnsen T, Gonzalez AM. Int J Sport Nutr Exerc Metab (2021)
Nutritional Ergogenic Aids in Racquet Sports: A Systematic Review. Vicente-Salar N, Santos-Sánchez G, Roche E. Nutrients (2020)
Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature. Gonzalez AM, Trexler ET. J Strength Cond Res (2020)
Effect of citrulline on post-exercise rating of perceived exertion, muscle soreness, and blood lactate levels: A systematic review and meta-analysis. Rhim HC, Kim SJ, Park J, Jang KM. J Sport Health Sci (2020)
Effects of Citrulline alone or combined with exercise on muscle mass, muscle strength, and physical performance among older adults: a systematic review. Aubertin-Leheudre M, Buckinx F. Curr Opin Clin Nutr Metab Care (2020)
Acute Effects of Citrulline Supplementation on High-Intensity Strength and Power Performance: A Systematic Review and Meta-Analysis. Trexler ET, Persky AM, Ryan ED, Schwartz TA, Stoner L, Smith-Ryan AE. Sports Med (2019)
Effect of food sources of nitrate, polyphenols, L-arginine and L-citrulline on endurance exercise performance: a systematic review and meta-analysis of randomised controlled trials. Noah M. A. d’Unienville, Henry T. Blake, Alison M. Coates, Alison M. Hill, Maximillian J. Nelson & Jonathan D. Buckley. J Int Soc Sports Nutr (2021) Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis. Vårvik FT, Bjørnsen T, Gonzalez AM. Int J Sport Nutr Exerc Metab (2021) Nutritional Ergogenic Aids in Racquet Sports: A Systematic Review. Vicente-Salar N, Santos-Sánchez G, Roche E. Nutrients (2020) Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature. Gonzalez AM, Trexler ET. J Strength Cond Res (2020) Effect of citrulline on post-exercise rating of perceived exertion, muscle soreness, and blood lactate levels: A systematic review and meta-analysis. Rhim HC, Kim SJ, Park J, Jang KM. J Sport Health Sci (2020) Effects of Citrulline alone or combined with exercise on muscle mass, muscle strength, and physical performance among older adults: a systematic review. Aubertin-Leheudre M, Buckinx F. Curr Opin Clin Nutr Metab Care (2020) Acute Effects of Citrulline Supplementation on High-Intensity Strength and Power Performance: A Systematic Review and Meta-Analysis. Trexler ET, Persky AM, Ryan ED, Schwartz TA, Stoner L, Smith-Ryan AE. Sports Med (2019)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
This tool is free. Please help keep it alive by buying me a beer:
Buy me a beer. Want free info like this in your inbox? Sign up here:
Proteins in our body are in a constant state of flux — they form and degrade, over and over. Consequently, there is a minimum daily dietary protein intake that is required to maintain normal function, which includes maintaining muscle mass. When we exercise, the rate at which muscle proteins form and breakdown increases, and following exercise, especially strength exercise, there is an “anabolic” window of opportunity during which we can eat protein to provide a supply of amino acids to help swing the protein synthesis/breakdown equilibrium in favour of more synthesis. You can go deep on these concepts at veohtu.com/protein, veohtu.com/postexercisenutrition, and veohtu.com/carbohydrateplusprotein.
The proteins in your body include enzymes, peptide hormones, neurotransmitters, and structural proteins, and they are made up of “building blocks” called amino acids. But some amino acids are not used to build proteins, possessing other physiological functions (including metabolic, immunological, neurological, etc). Some amino acids are coded by our genes; others are not. Some amino acids are synthesised in our body from other metabolites; others are not. Amino acids that we cannot synthesise and/or cannot synthesise quick enough to meet our basic daily demands are called “essential” amino acids. For these, we need a dietary source.
In humans, there are 9 “essential” amino acids — phenylalanine, threonine, tryptophan, methionine, leucine, isoleucine, valine, lysine, and histidine. These 9 include leucine, isoleucine, and valine, which are known as branched-chain amino acids (BCAAs). BCAAs are unique because they are both used to build proteins and have direct physiological effects. For example, leucine can act as a signal to increase muscle protein synthesis after a meal (see a systematic review on this topic here). Because BCAAs are “essential” amino acids, we need to eat BCAAs in our diet to maintain optimal function. But this is no problem... Omnivorous folks who eat meat can easily obtain all essential amino acids in adequate quantities. Folks who follow a plant-based diet can also easily obtain all essential amino acids in adequate quantities so long as they eat a variety of plants. You can read all about this at veohtu.com/protein.
Since BCAAs have several direct physiological functions and since leucine can promote muscle protein synthesis, BCAA and leucine supplements have been popularised by solid marketing to become widespread. But…
Do BCAAs (or leucine) improve performance — what do the systematic reviews say?
BCAAs are generally safe to consume.
BCAA supplementation may reduce post-exercise markers of muscle damage (blood levels of creatine kinase) and feelings of muscle soreness (DOMS) for 24 to 48-hours after a bout of strenuous exercise (typically strength exercise or plyometric exercise). The effect sizes range from moderate to large.
BCAA supplementation does not improve the recovery of muscle performance after exercise.
And, BCAA supplementation does not improve exercise performance.
In older adults (≥65 years old), especially folks with sarcopenia (muscle wasting), daily leucine supplementation may help maintain muscle mass (see systematic reviews here, here, and here) but the effect of daily leucine supplementation on muscle strength and performance in old age is not convincing. Current evidence shows that adequate daily protein intake combined with resistance training is an optimal approach for older adults to maintain muscle mass, strength, and function (see systematic reviews here). There is no current meta-analysis of leucine and performance in younger adults.
In general, there are few studies in this field and there is high variability between studies with regards to training status, different BCAA doses, time of treatment, and severity of muscle damage caused by exercise. Therefore, more high-quality randomised controlled trials are needed.
If you choose to use BCAAs or leucine, a reasonable dose is:
2 to 3 grams per day of leucine, or a BCAA mix containing ~2 g/day of leucine, ~1 g/d of isoleucine, and ~1 g/d of valine. Note: this is based on effective doses used in research.
Taking more doesn’t necessarily mean a bigger effect. And, don’t forget that whole foods can easily meets your needs…
100 grams of roasted chicken provides ~2.6 grams of leucine, and ~1.5 grams of both isoleucine and valine, plus ~24 grams of total protein, ~13 grams of fat including 3 grams of polyunsaturates, some sodium and potassium, a little bit of iron and vitamin A.
100 grams of tofu provides 1.4 grams of leucine, and 0.8 g of isoleucine, and 0.9 g of valine, plus ~10 grams of total protein, ~5 grams of fat, mostly from unsaturates, and some sodium, potassium, calcium, and iron.
To conclude…
While BCAA supplementation is likely to alleviate post-exercise muscle soreness, there is no evidence to suggest that taking a daily dose or single-dose pre/during/post-exercise BCAA or leucine supplement will boost your performance. Eating whole foods that contain protein provides us with the entire range of amino acids in adequate amounts. For this reason, when following a healthy eating pattern with an adequate daily protein intake, there is absolutely no rational basis for supplementing with specific amino acids because drinking a BCAA-containing drink or taking a leucine pill doesn’t initiate any magic on top of high-quality protein you have already ingested. In fact, supplementing with such things while neglecting whole foods may leave you deficient in total protein and lacking in other specific amino acids. So, if you want to “branch” out and get your BCAA fix, go and eat some tasty protein-containing whole food. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining BCAAs and leucine for performance.
Here is the list of systematic reviews I have summarised above.
The use of BCAA to decrease delayed-onset muscle soreness after a single bout of exercise: a systematic review and meta-analysis. Martim Gomes Weber, Silas Seolin Dias, Tarlyson Regioli de Angelis, Eduardo Vignoto Fernandes, Andrea Gomes Bernardes, Vinicius Flavio Milanez, Eduardo Inocente Jussiani, Solange de Paula Ramos. Amino acids (2021)
Intake of branched chain amino acids favors post-exercise muscle recovery and may improve muscle function: optimal dosage regimens and consumption conditions. Alejandra Arroyo-Cerezo, Isabel Cerrillo, Ángeles Ortega, María-Soledad Fernández-Pachón. J Sports Med Phys Fitness (2021)
Does Branched-Chain Amino Acids (BCAAs) Supplementation Attenuate Muscle Damage Markers and Soreness after Resistance Exercise in Trained Males? A Meta-Analysis of Randomized Controlled Trials. Chutimon Khemtong, Chia-Hua Kuo, Chih-Yen Chen, Salvador J Jaime, Giancarlo Condello. Nutrients (2021)
The effect of branched-chain amino acid on muscle damage markers and performance following strenuous exercise: a systematic review and meta-analysis. Kenji Doma, Utkarsh Singh, Daniel Boullosa, Jonathan Douglas Connor. Appl Physiol Nutr Metab (2021)
Nutritional interventions to improve muscle mass, muscle strength, and physical performance in older people: an umbrella review of systematic reviews and meta-analyses. Gielen E, Beckwée D, Delaere A, De Breucker S, Vandewoude M, Bautmans I; Sarcopenia Guidelines Development Group of the Belgian Society of Gerontology and Geriatrics (BSGG). Nutr Rev (2021)
Effect of Branched-Chain Amino Acid Supplementation on Muscle Soreness following Exercise: A Meta-Analysis. Fedewa MV, Spencer SO, Williams TD, Becker ZE, Fuqua CA. Int J Vitam Nutr Res (2019)
Branched-chain amino acid supplementation and exercise-induced muscle damage in exercise recovery: A meta-analysis of randomized clinical trials. Rahimi MH, Shab-Bidar S, Mollahosseini M, Djafarian K. Nutrition (2017)
Effects of branched amino acids in endurance sports: a review. (SPANISH) Salinas-García ME, Martínez-Sanz JM, Urdampilleta A, Mielgo-Ayuso J, Norte Navarro A, Ortiz-Moncada R. Nutr Hosp (2014)
The use of BCAA to decrease delayed-onset muscle soreness after a single bout of exercise: a systematic review and meta-analysis. Martim Gomes Weber, Silas Seolin Dias, Tarlyson Regioli de Angelis, Eduardo Vignoto Fernandes, Andrea Gomes Bernardes, Vinicius Flavio Milanez, Eduardo Inocente Jussiani, Solange de Paula Ramos. Amino acids (2021) Intake of branched chain amino acids favors post-exercise muscle recovery and may improve muscle function: optimal dosage regimens and consumption conditions. Alejandra Arroyo-Cerezo, Isabel Cerrillo, Ángeles Ortega, María-Soledad Fernández-Pachón. J Sports Med Phys Fitness (2021) Does Branched-Chain Amino Acids (BCAAs) Supplementation Attenuate Muscle Damage Markers and Soreness after Resistance Exercise in Trained Males? A Meta-Analysis of Randomized Controlled Trials. Chutimon Khemtong, Chia-Hua Kuo, Chih-Yen Chen, Salvador J Jaime, Giancarlo Condello. Nutrients (2021) The effect of branched-chain amino acid on muscle damage markers and performance following strenuous exercise: a systematic review and meta-analysis. Kenji Doma, Utkarsh Singh, Daniel Boullosa, Jonathan Douglas Connor. Appl Physiol Nutr Metab (2021) Nutritional interventions to improve muscle mass, muscle strength, and physical performance in older people: an umbrella review of systematic reviews and meta-analyses. Gielen E, Beckwée D, Delaere A, De Breucker S, Vandewoude M, Bautmans I; Sarcopenia Guidelines Development Group of the Belgian Society of Gerontology and Geriatrics (BSGG). Nutr Rev (2021) Effect of Branched-Chain Amino Acid Supplementation on Muscle Soreness following Exercise: A Meta-Analysis. Fedewa MV, Spencer SO, Williams TD, Becker ZE, Fuqua CA. Int J Vitam Nutr Res (2019) Branched-chain amino acid supplementation and exercise-induced muscle damage in exercise recovery: A meta-analysis of randomized clinical trials. Rahimi MH, Shab-Bidar S, Mollahosseini M, Djafarian K. Nutrition (2017) Effects of branched amino acids in endurance sports: a review. (SPANISH) Salinas-García ME, Martínez-Sanz JM, Urdampilleta A, Mielgo-Ayuso J, Norte Navarro A, Ortiz-Moncada R. Nutr Hosp (2014)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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β-hydroxy β-methylbutyrate (HMB) is part of the carboxylic acid family of organic compounds that circulates in micromolar (μM) concentrations in the blood. It is found in muscle, can cross the blood-brain barrier and is excreted in the urine. Our body can synthesise HMB from the branched-chain amino acid (BCAA), leucine. But HMB is also found in trace amounts in several foods, including asparagus, avocados, cauliflower, and grapefruit.
The biology of HMB has been studied for a long ole time and much is known. For example, it has been known since the 1990s that HMB supplementation during resistance training directly affects muscle function and it was discovered more recently that HMB simultaneously promotes muscle protein synthesis and prevents muscle protein breakdown. Therefore, HMB supplementation has the potential to increase muscle mass and, for this reason, HMB is often added to high-protein medical foods used to treat muscle wasting (cachexia) in diseases like cancer and AIDS. But…
Does HMB improve performance — what do the systematic reviews say?
HMB is generally safe to consume.
The vast majority of studies have examined HMB supplementation during strength training protocols while few studies have examined the effects of HMB supplementation during aerobic exercise interventions.
Daily HMB supplementation may have a small, positive impact on fat-free mass (FFM) in athletes (small effect size) with no effect on body mass or fat mass. But this effect is diminished in athletes consuming sufficient daily amounts of protein (at least 1.6 grams per day).
In older untrained adults (50 to 80 years old), daily HMB supplementation in the absence of strength training may help increase fat-free mass (small to moderate effect size) but HMB supplementation does not further improve body composition, muscle strength, or physical performance over that caused by strength training alone.
In younger adults (18 to 50 years old), daily HMB supplementation during a strength training intervention can increase muscle strength (small effect size) but these effects are only seen in previously untrained men. In trained athletes, daily HMB supplementation has no effect on muscle mass, muscle strength or performance (trivial effect size).
HMB may enhance recovery by reducing exercise-induced muscle damage but more high-quality work is needed for a meta-analysis. And, at this time, more studies are needed to determine the effect of HMB supplementation on endurance exercise performance.
If you choose to use HMB, a reasonable dose is:
Either 3 grams per day in a single dose or 3 daily 1 gram doses. Note: this is based on effective doses used in research.
This is equivalent to ~6000 avocados per day. Don’t eat that many avocados!
Taking more doesn’t necessarily mean a bigger effect.
To conclude…
If you are a trained athlete, the evidence suggests that taking HMB is unlikely to boost your performance. The effect size is trivial. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining HMB for performance.
Here is the list of systematic reviews I have summarised above.
An umbrella review of systematic reviews of β‐hydroxy‐β‐methyl butyrate supplementation in ageing and clinical practice. Stuart M. Phillips, Kyle J. Lau, Alysha C. D'Souza, Everson A. Nunes. J Cachexia Sarcopenia Muscle (2022)
Does HMB Enhance Body Composition in Athletes? A Systematic Review and Meta-analysis. Brett M Holland, Brandon M Roberts, James W Krieger, Brad J Schoenfeld. J Strength Cond Res (2022)
Effects of oral administration of β-hydroxy β-methylbutyrate on lean body mass in older adults: a systematic review and meta-analysis. Lin Z, Zhao Y, Chen Q. Eur Geriatr Med (2021)
Nutritional Strategies to Optimize Performance and Recovery in Rowing Athletes. Kim J, Kim EK. Nutrients (2020)
Supplementation with the Leucine Metabolite β-hydroxy-β-methylbutyrate (HMB) does not Improve Resistance Exercise-Induced Changes in Body Composition or Strength in Young Subjects: A Systematic Review and Meta-Analysis.
Jakubowski JS, Nunes EA, Teixeira FJ, Vescio V, Morton RW, Banfield L, Phillips SM. Nutrients (2020)
Does HMB Enhance Body Composition in Athletes? A Systematic Review and Meta-analysis. Holland BM, Roberts BM, Krieger JW, Schoenfeld BJ. J Strength Cond Res (2019)
Health Benefits of β-Hydroxy-β-Methylbutyrate (HMB) Supplementation in Addition to Physical Exercise in Older Adults: A Systematic Review with Meta-Analysis. Courel-Ibáñez J, Vetrovsky T, Dadova K, Pallarés JG, Steffl M. Nutrients (2019)
The Effects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Recovery Following Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis. Rahimi MH, Mohammadi H, Eshaghi H, Askari G, Miraghajani M. J Am Coll Nutr (2018)
Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trials. Sanchez-Martinez J, Santos-Lozano A, Garcia-Hermoso A, Sadarangani KP, Cristi-Montero C. J Sci Med Sport (2018)
β-hydroxy-β-methylbutyrate free acid supplementation may improve recovery and muscle adaptations after resistance training: a systematic review. Silva VR, Belozo FL, Micheletti TO, Conrado M, Stout JR, Pimentel GD, Gonzalez AM. Nutr Res (2017)
Beta-hydroxy-beta-methylbutyrate supplementation in health and disease: a systematic review of randomized trials. Molfino A, Gioia G, Rossi Fanelli F, Muscaritoli M. Amino Acids (2013)
Effects of beta-hydroxy-beta-methylbutyrate supplementation during resistance training on strength, body composition, and muscle damage in trained and untrained young men: a meta-analysis. Rowlands DS, Thomson JS. J Strength Cond Res (2009)
Effect of dietary supplements on lean mass and strength gains with resistance exercise: a meta-analysis. Nissen SL, Sharp RL. J Appl Physiol (2003)
An umbrella review of systematic reviews of β‐hydroxy‐β‐methyl butyrate supplementation in ageing and clinical practice. Stuart M. Phillips, Kyle J. Lau, Alysha C. D'Souza, Everson A. Nunes. J Cachexia Sarcopenia Muscle (2022)
Does HMB Enhance Body Composition in Athletes? A Systematic Review and Meta-analysis. Brett M Holland, Brandon M Roberts, James W Krieger, Brad J Schoenfeld. J Strength Cond Res (2022) Effects of oral administration of β-hydroxy β-methylbutyrate on lean body mass in older adults: a systematic review and meta-analysis. Lin Z, Zhao Y, Chen Q. Eur Geriatr Med (2021) Nutritional Strategies to Optimize Performance and Recovery in Rowing Athletes. Kim J, Kim EK. Nutrients (2020) Supplementation with the Leucine Metabolite β-hydroxy-β-methylbutyrate (HMB) does not Improve Resistance Exercise-Induced Changes in Body Composition or Strength in Young Subjects: A Systematic Review and Meta-Analysis.
Jakubowski JS, Nunes EA, Teixeira FJ, Vescio V, Morton RW, Banfield L, Phillips SM. Nutrients (2020) Does HMB Enhance Body Composition in Athletes? A Systematic Review and Meta-analysis. Holland BM, Roberts BM, Krieger JW, Schoenfeld BJ. J Strength Cond Res (2019) Health Benefits of β-Hydroxy-β-Methylbutyrate (HMB) Supplementation in Addition to Physical Exercise in Older Adults: A Systematic Review with Meta-Analysis. Courel-Ibáñez J, Vetrovsky T, Dadova K, Pallarés JG, Steffl M. Nutrients (2019) The Effects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Recovery Following Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis. Rahimi MH, Mohammadi H, Eshaghi H, Askari G, Miraghajani M. J Am Coll Nutr (2018) Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trials. Sanchez-Martinez J, Santos-Lozano A, Garcia-Hermoso A, Sadarangani KP, Cristi-Montero C. J Sci Med Sport (2018) β-hydroxy-β-methylbutyrate free acid supplementation may improve recovery and muscle adaptations after resistance training: a systematic review. Silva VR, Belozo FL, Micheletti TO, Conrado M, Stout JR, Pimentel GD, Gonzalez AM. Nutr Res (2017) Beta-hydroxy-beta-methylbutyrate supplementation in health and disease: a systematic review of randomized trials. Molfino A, Gioia G, Rossi Fanelli F, Muscaritoli M. Amino Acids (2013) Effects of beta-hydroxy-beta-methylbutyrate supplementation during resistance training on strength, body composition, and muscle damage in trained and untrained young men: a meta-analysis. Rowlands DS, Thomson JS. J Strength Cond Res (2009) Effect of dietary supplements on lean mass and strength gains with resistance exercise: a meta-analysis. Nissen SL, Sharp RL. J Appl Physiol (2003)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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Some amino acids are coded by our genes, some are used to build proteins; others are not. Beta-alanine is an amino acid but, unlike its familiar sibling L-alpha-alanine, it is not used as a “building block” for protein synthesis. Instead, beta-alanine can act as a neurotransmitter by binding to GABA receptors and NMDA receptors. But, beta-alanine is also a biochemical precursor to carnosine (aka β-alanyl-L-histidine), which is a dipeptide of beta-alanine and another amino acid called histidine. And, carnosine is an intracellular buffer — it helps regulate hydrogen ion (H+) concentrations (aka pH) in your cells.
β-alanine + histidine + ATP ⇌ carnosine + ADP + Pi
Carnosine is a particularly important pH buffer in muscle cells, and orally-ingested beta-alanine can increase muscle carnosine levels. Therefore, beta-alanine has become a popular sports supplement. So…
Does beta-alanine (or carnosine or anserine) improve performance — what do the systematic reviews say?
Beta-alanine is generally safe to consume (see here) but many folks experience a short-lived burning or prickling sensation throughout their body (aka paraesthesia) after taking it. These symptoms are reported in some but not all studies, and many studies in this field fail to comment on adverse effects.
Beta-alanine may help boost performance during short-duration high-intensity (highly glycolytic) exercise.
Beta-alanine supplementation seems most effective for high-intensity exercise lasting between 30-seconds and 10-minutes (early systematic reviews found a narrower optimal range of 1 to 4-mins).
There is no performance benefit of beta-alanine on very short duration exercise (less than 30-seconds).
A 2016 meta-analysis reports that daily beta-alanine co-supplementation with pre-exercise sodium bicarbonate results in the largest effect size when compared with placebo (effect size = 0.43, 95% CI 0.22 to 0.64). A 2021 systematic review confirms this observation.
Since beta-alanine is a biochemical precursor for carnosine, you may wonder why you shouldn’t take a carnosine supplement? Well… Oral carnosine is simply digested to histidine and beta-alanine in the stomach. That said, there is a methylated derivative of carnosine called anserine (carnosine with a —CH3 group attached to it) that is a dipeptide of beta-alanine and 3-methylhistidine that is resistant to degradation. Like carnosine, anserine is also a pH buffer found in muscle cells. Interestingly, chicken broth is very rich in carnosine and anserine, and preliminary evidence shows that eating chicken broth can increase cycling time trial performance when consumed before the effort.
There is not currently a systematic review of carnosine or anserine supplementation.
It is debated whether buffering compounds like beta-alanine are performance enhancing because of their H+ buffering capacity or whether they are performance enhancing because they also buffer the intramuscular phosphate (Pi) that accumulates during high-intensity exercise (which is a series of high force muscle contractions). Some evidence shows that H+ (hydrogen) and Pi (phosphate) ions in combination more strongly impair maximal isometric force and peak power than what either ion exerts individually. Therefore, H+ and Pi accumulation during high-intensity exercise may synergistically and additively reduce muscle function during fatigue.
If you choose to use beta-alanine, a reasonable dose is:
~6 grams every day for at least ~2- to 4-weeks is sufficient to raise muscle carnosine levels. Note: this is based on effective doses used in research.
Taking more doesn’t necessarily mean a bigger effect.
Since there is ~1 gram of carnosine in 600 mL of chicken broth, which is broken down to ~570 milligrams of beta-alanine, ~6 g/day of beta-alanine supplementation is equivalent to drinking ~6 litres of chicken broth per day (don’t do that!).
When supplementation is stopped, the timecourse for muscle carnosine levels to return to baseline levels is currently unclear. To conclude…
There’s lots of evidence to suggest that taking a daily beta-alanine supplement is very likely to boost your performance during high-intensity short-duration events lasting between 30-seconds and 10-minutes. The effect size is small. Insufficient data exists for a meta-analysis of carnosine or anserine supplementation. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining beta-alanine, carnosine, and anserine for performance.
Here is the list of systematic reviews I have summarised above.
Effects of beta-alanine supplementation on body composition: a GRADE-assessed systematic review and meta-analysis. Damoon Ashtary-Larky, Reza Bagheri, Matin Ghanavati, Omid Asbaghi, Alexei Wong, Jeffrey R Stout, Katsuhiko Suzuki. J Int Soc Sports Nutr (2022)
Effect of β-alanine and sodium bicarbonate co-supplementation on the body's buffering capacity and sports performance: A systematic review. Laura Gilsanz, Jaime López-Seoane, Sergio L Jiménez, Helios Pareja-Galeano. Crit Rev Food Sci Nutr (2021)
Individual Participant Data Meta-Analysis Provides No Evidence of Intervention Response Variation in Individuals Supplementing With Beta-Alanine. Gabriel Perri Esteves, Paul Swinton, Craig Sale, Ruth M James, Guilherme Giannini Artioli, Hamilton Roschel, Bruno Gualano, Bryan Saunders, Eimear Dolan. Int J Sport Nutr Exerc Metab (2021)
Effects of beta-alanine supplementation on Yo-Yo test performance: A meta-analysis. Jozo Grgic. Clin Nutr ESPEN (2021)
Effects of Beta-Alanine Supplementation on Physical Performance in Aerobic–Anaerobic Transition Zones: A Systematic Review and Meta-Analysis. Álvaro Huerta Ojeda, Camila Tapia Cerda, María Fernanda Poblete Salvatierra, Guillermo Barahona-Fuentes, and Carlos Jorquera Aguilera. Nutrients (2020)
Effect of Supplements on Endurance Exercise in the Older Population: Systematic Review. Martínez-Rodríguez A, Cuestas-Calero BJ, Hernández-García M, Martíez-Olcina M, Vicente-Martínez M, Rubio-Arias JÁ. Int J Environ Res Public Health (2020)
Nutritional Strategies to Optimize Performanceand Recovery in Rowing Athletes. Kim J, Kim EK. Nutrients (2020)
The Impact of Preconditioning Strategies Designed to Improve 2000-m Rowing Ergometer Performance in Trained Rowers: A Systematic Review and Meta-Analysis. Turnes T, Cruz RSO, Caputo F, De Aguiar RA. Int J Sports Physiol Perform (2019)
β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis. Saunders B, Elliott-Sale K, Artioli GG, Swinton PA, Dolan E, Roschel H, Sale C, Gualano B. Br J Sports Med (2017)
Effects of beta-alanine supplementation on performance and muscle fatigue in athletes and non-athletes of different sports: a systematic review. Berti Zanella P, Donner Alves F, Guerini de Souza C. J Sports Med Phys Fitness (2017)
The effects of beta-alanine supplementation on performance: a systematic review of the literature. Quesnele JJ, Laframboise MA, Wong JJ, Kim P, Wells GD. Int J Sport Nutr Exerc Metab (2014)
Effects of β-alanine supplementation on exercise performance: a meta-analysis. Hobson RM, Saunders B, Ball G, Harris RC, Sale C. Amino Acids (2012)
Effects of beta-alanine supplementation on body composition: a GRADE-assessed systematic review and meta-analysis. Damoon Ashtary-Larky, Reza Bagheri, Matin Ghanavati, Omid Asbaghi, Alexei Wong, Jeffrey R Stout, Katsuhiko Suzuki. J Int Soc Sports Nutr (2022)
Effect of β-alanine and sodium bicarbonate co-supplementation on the body's buffering capacity and sports performance: A systematic review. Laura Gilsanz, Jaime López-Seoane, Sergio L Jiménez, Helios Pareja-Galeano. Crit Rev Food Sci Nutr (2021) Individual Participant Data Meta-Analysis Provides No Evidence of Intervention Response Variation in Individuals Supplementing With Beta-Alanine. Gabriel Perri Esteves, Paul Swinton, Craig Sale, Ruth M James, Guilherme Giannini Artioli, Hamilton Roschel, Bruno Gualano, Bryan Saunders, Eimear Dolan. Int J Sport Nutr Exerc Metab (2021) Effects of beta-alanine supplementation on Yo-Yo test performance: A meta-analysis. Jozo Grgic. Clin Nutr ESPEN (2021) Effects of Beta-Alanine Supplementation on Physical Performance in Aerobic–Anaerobic Transition Zones: A Systematic Review and Meta-Analysis. Álvaro Huerta Ojeda, Camila Tapia Cerda, María Fernanda Poblete Salvatierra, Guillermo Barahona-Fuentes, and Carlos Jorquera Aguilera. Nutrients (2020) Effect of Supplements on Endurance Exercise in the Older Population: Systematic Review. Martínez-Rodríguez A, Cuestas-Calero BJ, Hernández-García M, Martíez-Olcina M, Vicente-Martínez M, Rubio-Arias JÁ. Int J Environ Res Public Health (2020) Nutritional Strategies to Optimize Performanceand Recovery in Rowing Athletes. Kim J, Kim EK. Nutrients (2020) The Impact of Preconditioning Strategies Designed to Improve 2000-m Rowing Ergometer Performance in Trained Rowers: A Systematic Review and Meta-Analysis. Turnes T, Cruz RSO, Caputo F, De Aguiar RA. Int J Sports Physiol Perform (2019) β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis. Saunders B, Elliott-Sale K, Artioli GG, Swinton PA, Dolan E, Roschel H, Sale C, Gualano B. Br J Sports Med (2017) Effects of beta-alanine supplementation on performance and muscle fatigue in athletes and non-athletes of different sports: a systematic review. Berti Zanella P, Donner Alves F, Guerini de Souza C. J Sports Med Phys Fitness (2017) The effects of beta-alanine supplementation on performance: a systematic review of the literature. Quesnele JJ, Laframboise MA, Wong JJ, Kim P, Wells GD. Int J Sport Nutr Exerc Metab (2014) Effects of β-alanine supplementation on exercise performance: a meta-analysis. Hobson RM, Saunders B, Ball G, Harris RC, Sale C. Amino Acids (2012)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
This tool is free. Please help keep it alive by buying me a beer:
Buy me a beer. Want free info like this in your inbox? Sign up here:
Sodium bicarbonate (NaHCO3) is a salt made up of a sodium cation (Na+) and a bicarbonate anion (HCO3-) that is commonly used in cooking. In fact, sodium bicarbonate probably sits in your kitchen cupboard hidden among the ingredients of baking soda (aka bicarbonate of soda).
2 NaHCO3 → Na2CO3 + CO2 + H2O
Note: this reaction does not occur in your body.
But, I’m headed off-piste… To stay on topic, sodium bicarbonate is also the active ingredient in antacid drugs because it neutralizes stomach acid and subsequently relieves heartburn and indigestion. When sodium bicarbonate encounters acid (hydrogen ions, H+; or hydrogen chloride, HCl, in the stomach), it reacts in an acid-base reaction, again releasing sodium ions (Na+; or sodium chloride, NaCl, in the stomach) and carbon dioxide:
Note: this reaction does not occur in your body.
NaHCO3 + H+ → Na+ + CO2 + H2O
Now you’re probably starting to see how bicarbonate might work in the context of exercise…
Your body has an in-built bicarbonate buffering system that helps keep pH under control. This is important because various processes in your body operate optimally at a specific pH. Your stomach, for example, operates optimally at an “acidic” pH, which would destroy the epithelial cell lining of your gastrointestinal system (the gastric mucosa) if the bicarbonate buffering system wasn’t present to protect the cells from stomach acid. Meanwhile, your blood is maintained at a “neutral” pH because of the bicarbonate buffering system that helps minimise the fluctuations in carbon dioxide (CO2) and hydrogen ions (H+) resulting from energy metabolism. If, for example, physiological conditions cause a rise in your blood CO2 and hydrogen ion (H+) concentrations (a drop in pH), your bicarbonate buffering system buffers the H+ ions and helps transport CO2 to the lungs so you can puff it out into the air.
CO2 + H2O ⇌ H2CO3 ⇌ HCO3- + H+
Carbon dioxide + Water ⇌ Carbonic acid ⇌ Bicarbonate + Hydrogen ion
Like all buffers, the bicarbonate buffering system in your body consists of a weak acid (carbonic acid, H2CO3) and its conjugate base (bicarbonate, HCO3--) that helps neutralise any excess acid or base that appears. During high-intensity, highly-glycolytic exercise — that is when your need for ATP must be met by rapid glucose metabolism — you produce carbon dioxide (CO2) at a high rate and hydrogen ions (H+) can accumulate possibly causing intramuscular acidosis, which is one (of many) theorised causes of fatigue. Therefore, a buffering supplement has the potential to help your in-house bicarbonate buffering system overcome the large disturbance in the force. Consequently, sodium bicarbonate has become a popular supplement. And, it ain’t new — famous exercise physiologists like David Bruce (D.B.) Dill in the Harvard Fatigue Laboratory were studying the effects of sodium bicarbonate in runners over 100-years ago! But…
Carbon dioxide + Water ⇌ Carbonic acid ⇌ Bicarbonate + Hydrogen ion
Does sodium bicarbonate improve performance — what do the systematic reviews say?
Sodium bicarbonate is generally safe to consume and supplementation increases blood bicarbonate levels but it can also cause gastrointestinal issues in some folks.
Sodium bicarbonate supplementation before exercise improves muscular endurance (e.g. reps to failure and time-to-maintain isometric force) during tests of repeated muscular contraction in single muscle groups (knee extension, elbow flexion) and compound lifts (squat, bench press, pull-up), with a small effect size.
But, sodium bicarbonate supplementation does not improve muscular strength.
For long-duration endurance exercise, sodium bicarbonate supplementation does not enhance endurance performance (in humans… nor in horses; yes, “it is time to stop horsing around with baking soda”).
In short-duration, high-intensity exercise performance tests lasting between ∼45-seconds and 8-minutes, sodium bicarbonate supplementation may enhance performance with a trivial to small effect size. However, the risk of bias is unclear and there is evidence of publication bias in favour of only reporting and/or publishing positive findings. More high-quality studies are needed.
In very-short duration, high-intensity Wingate tests (“all-out” cycling for 30 seconds on a cycling ergometer), pre-exercise sodium bicarbonate supplementation does not enhance peak or mean (average) power output but pre-exercise sodium bicarbonate supplementation does have a beneficial effect (small effect size) on mean (average) power during repeated Wingate sprints.
There is a current sex bias in this field with only 20% of studies recruiting females but a preliminary meta-analysis shows that the effects of sodium bicarbonate supplementation are similar between males and females.
It is currently unclear whether daily supplementation of sodium bicarbonate causes a greater performance-enhancing effect than a single pre-exercise dose. That said, a 2018 meta-analysis found only a trivial effect of pre-exercise sodium bicarbonate supplementation on peak and average power during a sprint cycling Wingate test (effect size Hedges’ g = 0.02, 95% confidence interval –0.19 to +0.23) but a large effect size (Hedges’s g = 1.21, 95% CI: 0.83 to 1.42) following daily supplementation. But, this was based on a meta-analysis of only daily supplementation two studies so more studies are needed to substantiate this finding.
A 2016 meta-analysis reports that pre-exercise sodium bicarbonate supplementation superimposed on daily beta-alanine supplementation results in the largest effect size when compared with placebo (effect size = 0.43, 95% CI 0.22 to 0.64). This finding was confirmed in a 2021 systematic review. Suggesting that combining beta-alanine with sodium bicarb may be of benefit to folks engaged in short-duration, high-intensity efforts.
If you choose to use Sodium bicarbonate, a reasonable dose is:
0.2 to 0.3 grams per kilogram bodyweight taken 1- to 3-hours prior to high-intensity exercise. Note: this is based on effective doses used in research.
Taking more doesn’t necessarily mean a bigger effect but high-quality dose-response studies are lacking.
To conclude…
There is some evidence to suggest that taking sodium bicarbonate before a session or race is likely to boost your performance during high-intensity short-duration events lasting between ∼45-seconds and 8-minutes. The evidence also suggests that taking sodium bicarbonate before exercise is likely to improve muscle endurance “reps-to-failure” and repeated maximal sprint power. The effect size is small. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining sodium bicarbonate for performance.
Here is the list of systematic reviews I have summarised above.
Effects of Sodium Bicarbonate Ingestion on Measures of Wingate Test Performance: A Meta-Analysis. Jozo Grgic. J Am Nutr Assoc (2022)
Sodium bicarbonate supplementation and the female athlete: A brief commentary with small scale systematic review and meta-analysis. Saunders B, Oliveira LF, Dolan E, Durkalec-Michalski K, McNaughton L, Artioli GG, Swinton PA. Eur J Sport Sci (2021)
Effect of β-alanine and sodium bicarbonate co-supplementation on the body's buffering capacity and sports performance: A systematic review. Laura Gilsanz, Jaime López-Seoane, Sergio L Jiménez, Helios Pareja-Galeano. Crit Rev Food Sci Nutr (2021)
Extracellular Buffering Supplements to Improve Exercise Capacity and Performance: A Comprehensive Systematic Review and Meta-analysis. Luana Farias de Oliveira, Eimear Dolan, Paul A Swinton, Krzysztof Durkalec-Michalski, Guilherme G Artioli, Lars R McNaughton, Bryan Saunders. Sports Med (2021).
Effects of sodium bicarbonate supplementation on exercise performance: an umbrella review.
Jozo Grgic, Ivana Grgic, Juan Del Coso, Brad J Schoenfeld, Zeljko Pedisic. J Int Soc Sports Nutr (2021)
Effect of sodium bicarbonate supplementation on two different performance indicators in sports: a systematic review with meta-analysis. Lino RS, Lagares LS, Oliveira CVC, Queiroz CO, Pinto LLT, Almeida LAB, Bonfim ES, Santos CPCD. Phys Act Nutr (2021)
Effects of diet interventions, dietary supplements, and performance-enhancing substances on the performance of CrossFit-trained individuals: A systematic review of clinical studies. Dos Santos Quaresma MVL, Guazzelli Marques C, Nakamoto FP. Nutrition (2021)
A Systematic Review and Meta-analysis on Sodium Bicarbonate Administration and Equine Running Performance: Is it Time to Stop Horsing Around With Baking Soda? Denham J, Hulme A. J Equine Vet Sci (2020)
Effects of Sodium Bicarbonate Supplementation on Muscular Strength and Endurance: A Systematic Review and Meta-analysis. Grgic J, Rodriguez RF, Garofolini A, Saunders B, Bishop DJ, Schoenfeld BJ, Pedisic Z. Sports Med (2020)
Isolated effects of caffeine and sodium bicarbonate ingestion on performance in the Yo-Yo test: A systematic review and meta-analysis. Grgic J, Garofolini A, Pickering C, Duncan MJ, Tinsley GM, Del Coso J. J Sci Med Sport (2020)
The Impact of Preconditioning Strategies Designed to Improve 2000-m Rowing Ergometer Performance in Trained Rowers: A Systematic Review and Meta-Analysis. Turnes T, Cruz RSO, Caputo F, De Aguiar RA. Int J Sports Physiol Perform (2019)
The Impact of Sodium Bicarbonate on Performance in Response to Exercise Duration in Athletes: A Systematic Review. Hadzic M, Eckstein ML, Schugardt M. J Sports Sci Med (2019)
Acute and chronic effect of sodium bicarbonate ingestion on Wingate test performance: a systematic review and meta-analysis. Lopes-Silva JP, Reale R, Franchini E. J Sports Sci (2019)
β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis. Saunders B, Elliott-Sale K, Artioli GG, Swinton PA, Dolan E, Roschel H, Sale C, Gualano B. Br J Sports Med (2017)
A systematic review of the efficacy of ergogenic aids for improving running performance. Schubert MM, Astorino TA. J Strength Cond Res (2013)
Practical recommendations for coaches and athletes: a meta-analysis of sodium bicarbonate use for athletic performance. Peart DJ, Siegler JC, Vince RV. J Strength Cond Res (2012)
Effects of acute alkalosis and acidosis on performance: a meta-analysis. Carr AJ, Hopkins WG, Gore CJ. Sports Med (2011)
Effects of sodium bicarbonate ingestion on anaerobic performance: a meta-analytic review. Matson LG, Tran ZV. Int J Sport Nutr (1993) .
Effects of Sodium Bicarbonate Ingestion on Measures of Wingate Test Performance: A Meta-Analysis. Jozo Grgic. J Am Nutr Assoc (2022) Sodium bicarbonate supplementation and the female athlete: A brief commentary with small scale systematic review and meta-analysis. Saunders B, Oliveira LF, Dolan E, Durkalec-Michalski K, McNaughton L, Artioli GG, Swinton PA. Eur J Sport Sci (2021) Effect of β-alanine and sodium bicarbonate co-supplementation on the body's buffering capacity and sports performance: A systematic review. Laura Gilsanz, Jaime López-Seoane, Sergio L Jiménez, Helios Pareja-Galeano. Crit Rev Food Sci Nutr (2021) Extracellular Buffering Supplements to Improve Exercise Capacity and Performance: A Comprehensive Systematic Review and Meta-analysis. Luana Farias de Oliveira, Eimear Dolan, Paul A Swinton, Krzysztof Durkalec-Michalski, Guilherme G Artioli, Lars R McNaughton, Bryan Saunders. Sports Med (2021). Effects of sodium bicarbonate supplementation on exercise performance: an umbrella review.
Jozo Grgic, Ivana Grgic, Juan Del Coso, Brad J Schoenfeld, Zeljko Pedisic. J Int Soc Sports Nutr (2021) Effect of sodium bicarbonate supplementation on two different performance indicators in sports: a systematic review with meta-analysis. Lino RS, Lagares LS, Oliveira CVC, Queiroz CO, Pinto LLT, Almeida LAB, Bonfim ES, Santos CPCD. Phys Act Nutr (2021) Effects of diet interventions, dietary supplements, and performance-enhancing substances on the performance of CrossFit-trained individuals: A systematic review of clinical studies. Dos Santos Quaresma MVL, Guazzelli Marques C, Nakamoto FP. Nutrition (2021) A Systematic Review and Meta-analysis on Sodium Bicarbonate Administration and Equine Running Performance: Is it Time to Stop Horsing Around With Baking Soda? Denham J, Hulme A. J Equine Vet Sci (2020) Effects of Sodium Bicarbonate Supplementation on Muscular Strength and Endurance: A Systematic Review and Meta-analysis. Grgic J, Rodriguez RF, Garofolini A, Saunders B, Bishop DJ, Schoenfeld BJ, Pedisic Z. Sports Med (2020) Isolated effects of caffeine and sodium bicarbonate ingestion on performance in the Yo-Yo test: A systematic review and meta-analysis. Grgic J, Garofolini A, Pickering C, Duncan MJ, Tinsley GM, Del Coso J. J Sci Med Sport (2020) The Impact of Preconditioning Strategies Designed to Improve 2000-m Rowing Ergometer Performance in Trained Rowers: A Systematic Review and Meta-Analysis. Turnes T, Cruz RSO, Caputo F, De Aguiar RA. Int J Sports Physiol Perform (2019) The Impact of Sodium Bicarbonate on Performance in Response to Exercise Duration in Athletes: A Systematic Review. Hadzic M, Eckstein ML, Schugardt M. J Sports Sci Med (2019) Acute and chronic effect of sodium bicarbonate ingestion on Wingate test performance: a systematic review and meta-analysis. Lopes-Silva JP, Reale R, Franchini E. J Sports Sci (2019) β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis. Saunders B, Elliott-Sale K, Artioli GG, Swinton PA, Dolan E, Roschel H, Sale C, Gualano B. Br J Sports Med (2017) A systematic review of the efficacy of ergogenic aids for improving running performance. Schubert MM, Astorino TA. J Strength Cond Res (2013) Practical recommendations for coaches and athletes: a meta-analysis of sodium bicarbonate use for athletic performance. Peart DJ, Siegler JC, Vince RV. J Strength Cond Res (2012) Effects of acute alkalosis and acidosis on performance: a meta-analysis. Carr AJ, Hopkins WG, Gore CJ. Sports Med (2011) Effects of sodium bicarbonate ingestion on anaerobic performance: a meta-analytic review. Matson LG, Tran ZV. Int J Sport Nutr (1993) .
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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Carnitine gained some notoriety because it was one of the “supplements” that played a starring role in the Alberto Salazar-associated Mo Farah debacle. In the world of medicine, carnitine is sometimes used in patients with peripheral artery disease to help treat a symptom called “intermittent claudication” — jargon for muscle pain/soreness/aching during exertion, particularly in the calf muscles during walking. This symptom usually subsides when the patient stops walking and it occurs because of impairments in blood flow and energy metabolism (muscle carnitine deficiency, which reduces fat metabolism). Several systematic reviews (see here, here, here, & here) show that oral or intravenous administration of either L-carnitine or propionyl-L-carnitine (a derivative) is a useful add-on therapy for treating intermittent claudication and improving walking capacity in folks with peripheral artery disease. Sounds exciting… but, first up, what is carnitine?
Carnitine is an amino acid predominantly found in muscle tissue. Some amino acids are coded by our genes, some are used to build proteins; others are not. Carnitine is not coded by our genes and is not used to build proteins; instead, our body can synthesise it from other amino acids (methionine and lysine). But, meat-eating folks also obtain a large proportion of carnitine in their diet. But, what does it do?
At rest and during low to moderate-intensity exercise, our body predominantly “burns” fatty acids to produce energy (ATP). To do so, fatty acids must be transported into the mitochondria of our cells so they can be “oxidised” (aka metabolised). Carnitine is of great importance because it helps “shuttle” fatty acid molecules into your mitochondria (via the carnitine palmitoyltransferase system) so they can be metabolised (via beta-oxidation) to produce lots of ATP (chemical energy). So, during exercise, the carnitine palmitoyltransferase system acts as a gateway to allow fat “burning”.
Supplementing with L-carnitine or propionyl-L-carnitine increases intracellular carnitine concentrations in muscle. Furthermore, propionyl-L-carnitine (a carnitine derivative) has a higher affinity for muscular carnitine transferase enzyme and produces propionyl-coA in the mitochondria, which is synthesised to succinyl-CoA, entering the Krebs cycle to produce energy. Double win.
Since L-carnitine or propionyl-L-carnitine supplementation can increase muscle levels of carnitine and since doing so can improve walking capacity in folks with peripheral artery disease, the big question is…
Does L-Carnitine (or propionyl-L-carnitine) improve performance — what do the systematic reviews say?
L-carnitine / propionyl-L-carnitine is generally safe to consume.
Acute L-carnitine / propionyl-L-carnitine supplementation before exercise or daily L-carnitine / propionyl-L-carnitine supplementation may improve exercise performance during high-intensity tasks (≥80% V̇O2max).
But, there are only a few studies that have examined moderate (50 to 79% V̇O2max) and there is wide variability among study designs in different studies.
Very little data exists in trained athletes. More high-quality studies are needed.
Also, two unanswered questions remain, and high-quality randomised controlled trials are needed to answer them: 
Does orally-ingested carnitine reach the muscle and its mitochondrial membranes?
Is propionyl-L-carnitine a better choice?
Only one randomised controlled trial has compared propionyl-L-carnitine vs. L-carnitine, finding greater benefit of propionyl-L-carnitine on exercise capacity. But, this was in folks with peripheral artery disease.
If you choose to use L-carnitine / propionyl-L-carnitine, a reasonable dose is:
3 to 4 grams ~60 to 90-minutes before exercise Or
2 to 3 grams per day for 9- to 24-weeks. Note: this is based on effective doses used in research.
Taking more doesn’t necessarily mean a bigger effect.
When supplementation is stopped, the timecourse for muscle carnitine levels to return to baseline levels is currently unclear.
To conclude…
There is some limited evidence to suggest that taking L-carnitine either daily or before a session or race might boost your performance during high-intensity exercise. The effect size is currently unknown because a quality meta-analysis is lacking. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining (propionyl) L-carnitine for performance.
Here is the list of systematic reviews I have summarised above.
Effect of Acute and Chronic Oral L-Carnitine Supplementation on Exercise Performance Based on the Exercise Intensity: A Systematic Review. Juan Mielgo-Ayuso, Laura Pietrantonio, Aitor Viribay, Julio Calleja-González, Jerónimo González-Bernal, Diego Fernández-Lázaro. Nutrients (2021).
Clinical Effects of L-Carnitine Supplementation on Physical Performance in Healthy Subjects, the Key to Success in Rehabilitation: A Systematic Review and Meta-Analysis from the Rehabilitation Point of View. Michele Vecchio, Rita Chiaramonte ,Gianluca Testa and Vito Pavone. J Funct Morphol Kinesiol (2021).
Effect of Acute and Chronic Oral L-Carnitine Supplementation on Exercise Performance Based on the Exercise Intensity: A Systematic Review. Juan Mielgo-Ayuso, Laura Pietrantonio, Aitor Viribay, Julio Calleja-González, Jerónimo González-Bernal, Diego Fernández-Lázaro. Nutrients (2021).
Clinical Effects of L-Carnitine Supplementation on Physical Performance in Healthy Subjects, the Key to Success in Rehabilitation: A Systematic Review and Meta-Analysis from the Rehabilitation Point of View. Michele Vecchio, Rita Chiaramonte ,Gianluca Testa and Vito Pavone. J Funct Morphol Kinesiol (2021).
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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Ketones are naturally occurring metabolites produced in your body that include acetate, acetoacetate, and β-hydroxybutyrate. They normally circulate in the blood in trace amounts (less than 0.5 millimoles/litre, 0.5 mM) but levels can rise under certain conditions. Ketosis is a metabolic state characterised by elevated concentrations (0.5 to 3 mM) of ketone bodies (acetate, acetoacetate, & β-hydroxybutyrate) in your blood (and urine) caused by depletion of carbohydrate stores (low glycogen) in the body. This typically happens during starvation, prolonged exercise, or a prolonged fast (not eating any calories for at least 12 hours), or in folks who eat a very low carbohydrate diet (less than 50 grams of carbs per day). This would be called “physiological ketosis” because ketone levels are elevated but not enough to cause acidosis. This is a little different from ketoacidosis, a pathophysiological state that can occur in patients with diabetes who develop prolonged hypoglycemia (low blood glucose) and blood ketones of up to 10 mM or more — ketoacidosis requires urgent medical care while physiological ketosis does not.
When elevated, ketones provide an additional fuel source to support your brain’s energy needs when glucose availability is low (depleted glycogen + low blood glucose). Under such conditions, your liver metabolises triglycerides/fatty acids, releasing ketones into the blood, which are then transported into the brain. But, besides the physiological/pathophysiological events that cause ketosis, ingesting ketones also raises blood ketone concentrations causing ketosis without the need for restricting the intake of calories or carbohydrates (see here & here). This is typically achieved by consuming a ketone ester (e.g. (R)-3-hydroxybutyl (R)-3-hydroxybutyrate) or a ketone precursor (e.g. R-1,3-butanediol). Ketone supplementation has gathered momentum and systematic reviews show that a single dose of ketones can decrease blood glucose concentrations, showing its potential for diabetes treatment. There are also studies showing how ketone supplementation may affect appetite and cognitive function in humans, but more high-quality studies are needed before definitive conclusions can be made.
The first published exercise study using ketone supplementation found increased fat oxidation during exercise and improved time-trial performance even in the presence of high carbohydrate availability (normal muscle glycogen levels and during-exercise carbohydrate ingestion). Consequently, popular science media is awash with the benefits of ketones for athletic performance and several companies sell ketone-containing products. The most heavily marketed ketone supplement is the “drinkable ketone” from HVMN, which contains a ketone precursor (R-1,3-butanediol) that is converted to β-hydroxybutyrate (a ketone) in the body. If you follow pro cycling, you will hear a lot about this product because they sponsor a large number of the pro teams. But sexy marketing is not part of the scientific method. So…
Do ketones improve performance — what do the systematic reviews say?
Ketones are generally safe to consume.
Acute (single dose) or chronic (daily) supplementation with ketone esters or ketones precursors does not improve endurance performance (including time-to-exhaustion and time trial tests across a range of durations from 90-seconds to 2-hours).
There is no difference in the effect of ketone esters and ketone precursors on endurance performance.
At this time, there is no systematic review has included studies examining the ultra-distance effects of ketone supplementation. Since ketones become relevant when glycogen is depleted and blood glucose is low, this seems a prudent area of study that needs addressing.
At this time, there is no systematic review on the effect of ketone supplementation on strength performance.
The ketone supplement world seems to be one of those “first paper dogma” stories where the first paper published (Cox et al. 2016 Cell Metabolism) found a beneficial effect but subsequent studies did not confirm the findings yet the media kept echoing the narrative of “ketones are the bomb”.
The individual studies in this field vary widely in the designs and methodologies. The duration of exercise performance testing is highly variable (90-seconds to 2-hours), there is inconsistency in whether folks are fed or fasted during testing and many studies use carbohydrate co-ingestion with the ketone supplement. This makes it challenging to compare different trials. More high-quality randomised controlled trials are needed, especially in trained athletes.
The individual studies that found small to moderate effect sizes also used higher doses of ketone supplements that pushed plasma β-hydroxybutyrate levels above 2 mM (see Figure 4 in Margolis et al. 2020). Since dose-response studies are lacking, again, more high-quality randomised controlled trials are needed.
If you choose to use a ketone supplement, a reasonable dose is:
Taken before exercise at a dose that elevates your blood β-hydroxybutyrate concentration to at least 2 mM. Note: this is based on effective doses used in research.
To conclude…
The current evidence suggests that ketone supplementation is unlikely to improve your endurance performance. The effect size is trivial. But, more high-quality randomised controlled trials are needed especially trials examining ultra-endurance performance. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining ketones for performance.
Here is the list of systematic reviews I have summarised above.
Acute Ingestion of Ketone Monoesters and Precursors Do Not Enhance Endurance Exercise Performance: A Systematic Review and Meta-Analysis. Emma Brooks, Gilles Lamothe, Taniya S Nagpal, Pascal Imbeault, Kristi Adamo, Jameel Kara, Éric Doucet. Int J Sport Nutr Exerc Metab (2022).
Utility of Ketone Supplementation to Enhance Physical Performance: A Systematic Review. Margolis LM, O'Fallon KS. Adv Nutr (2020).
Acute Ketone Supplementation and Exercise Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Valenzuela PL, Morales JS, Castillo-García A, Lucia A. Int J Sports Physiol Perform (2020).
Acute Ingestion of Ketone Monoesters and Precursors Do Not Enhance Endurance Exercise Performance: A Systematic Review and Meta-Analysis. Emma Brooks, Gilles Lamothe, Taniya S Nagpal, Pascal Imbeault, Kristi Adamo, Jameel Kara, Éric Doucet. Int J Sport Nutr Exerc Metab (2022).
Utility of Ketone Supplementation to Enhance Physical Performance: A Systematic Review. Margolis LM, O'Fallon KS. Adv Nutr (2020).
Acute Ketone Supplementation and Exercise Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Valenzuela PL, Morales JS, Castillo-García A, Lucia A. Int J Sports Physiol Perform (2020).
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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CBD (cannabidiol) and THC (tetrahydrocannabinol) belong to a class of chemicals called, cannabinoids. THC is the main cannabinoid that provides the relaxing “high” plus a bunch of other side effects (paranoia, sleepiness, short-term memory loss, dizziness, confusion, reduced coordination, slurred speech) when smoking/eating/vaping marijuana (or when eating “edibles” containing isolated THC). On the other hand, CBD is isolated from dried, crushed cannabis plants and does not have any psychoactive properties but is alleged to relieve pain, improve sleep, and reduce inflammation.
Cannabinoids have been used to develop some drugs. For example, CBD is the active ingredient in Epidiolex, which is prescribed to treat seizures in patients with rare forms of epilepsy; while THC is the active ingredient in Nabiximols/Sativex, which is used to treat pain in patients with multiple sclerosis. Beyond that, “medical marijuana” is now prescribed in some countries, while some folks recreationally use THC-containing “edibles” or smoke marijuana to relieve anxiety and pain caused by chronic disease. However, despite being a prescription drug in some countries, the overall effect and risk/benefit balance of marijuana is debated. All that said, business is booming for CBD and THC. And, the theoretical benefits of cannabinoids in sports are frequently reported. Plus, the world has gone wild for CBD oils and tinctures and rubs with abundant claims of greatest for athletes. So, the important question…
Do CBD or THC or cannabis improve performance — what do the systematic reviews say?
CBD and THC are generally safe to consume, but some studies indicate that chronic (long-term regular) use of THC or smoking cannabis is associated with addiction, and cognitive impairments.
That said, inhaling solid particles and other chemicals into your lungs — smoking (cigarettes or cannabis) — may impair lung function, which is not a smart athlete’s goal.
At the time of writing, CBD is not on WADA’s prohibited list but WADA does prohibit the in-competition use of other cannabinoids, including THC. Also, be aware that many CBD-containing products are contaminated with THC. Effects of THC & cannabis:
Neither THC or cannabis improve exercise performance (either endurance or strength) or markers of performance (e.g. V̇O2max).
Furthermore, when taken before exercise, THC and cannabis increase breathing rate, impair balance and reduce strength and maximal work capacity — reasons not to indulge before exercise.
Some evidence suggests that THC and cannabis cause psychotropic enhancement and pain reduction. This may aid some sports and probably explains why THC and cannabis remain on WADA’s “in competition” prohibited list. But the side effects of THC/cannabis (e.g. sleepiness, short-term memory loss, dizziness, confusion, reduced coordination, slurred speech) may raise a safety issue in some sports; another reason they exist on WADA’s prohibited list. Furthermore, cannabis is an illegal drug in many countries; another reason WADA is keeping it on the prohibited list. Effects of CBD:
CBD is a very well-marketed product that “treats all ailments” and “improves all aspects” of human physiology. At this time, those effects are anecdotal and evidence from high-quality randomised controlled trials does not exist to support the narrative.
But an absence of evidence is not evidence of absence. At this time, because of the lack of randomised controlled trials, there is not a systematic review examining the effect of CBD on performance or on recovery after exercise (that will no doubt change soon).
In the meantime, a 2020 narrative review by McCartney and colleagues dug into the evidence, concluding that “the available evidence is preliminary, at times inconsistent, and largely based on preclinical studies involving laboratory animals”.
One problem with the widespread outbreak of over-the-counter CBD products is that CBD is treated as a dietary supplement and, therefore, CBD products are monitored but not regulated. One study analysed the CBD content of an array of CBD oils and of the 25 products, only 3 were within 20% of the claimed amount, 15 were well below the claimed amount, 3 contained THC in amounts above the legal limit, and 5 products did not state the CBD content at all. This is a problem for athletes wanting to use CBD products, so be warned. To conclude…
THC and cannabis will not enhance your performance — cannabis is more likely to impair your performance than be of benefit. For CBD, only anecdotes promote its use and the evidence suggests that CBD is highly unlikely to enhance your performance. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining CBD, THC, and cannabis for performance.
Here is the list of systematic reviews I have summarised above.
Chronic cannabis consumption and physical exercise performance in healthy adults: a systematic review. Andrew Kramer, Justin Sinclair, Lara Sharpe, Jerome Sarris. J Cannabis Res (2022)
Acute effects of cannabis consumption on exercise performance: a systematic and umbrella review. Charron J, Carey V, Marcotte L'heureux V, Roy P, Comtois AS, Ferland PM. J Sports Med Phys Fitness (2021).
Cannabis Use and Sport: A Systematic Review. Shgufta Docter, Moin Khan, Chetan Gohal, Bheeshma Ravi, Mohit Bhandari, Rajiv Gandhi, Timothy Leroux. Sports Health (2020).
Chronic cannabis consumption and physical exercise performance in healthy adults: a systematic review. Kramer A, Sinclair J, Sharpe L, Sarris J. J Cannabis Res (2020).
Cannabis: Exercise performance and sport. A systematic review. Kennedy MC. J Sci Med Sport (2017).
Chronic cannabis consumption and physical exercise performance in healthy adults: a systematic review. Andrew Kramer, Justin Sinclair, Lara Sharpe, Jerome Sarris. J Cannabis Res (2022)
Acute effects of cannabis consumption on exercise performance: a systematic and umbrella review. Charron J, Carey V, Marcotte L'heureux V, Roy P, Comtois AS, Ferland PM. J Sports Med Phys Fitness (2021).
Cannabis Use and Sport: A Systematic Review. Shgufta Docter, Moin Khan, Chetan Gohal, Bheeshma Ravi, Mohit Bhandari, Rajiv Gandhi, Timothy Leroux. Sports Health (2020).
Chronic cannabis consumption and physical exercise performance in healthy adults: a systematic review. Kramer A, Sinclair J, Sharpe L, Sarris J. J Cannabis Res (2020).
Cannabis: Exercise performance and sport. A systematic review. Kennedy MC. J Sci Med Sport (2017).
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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Fish oils are rich in DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), which are long-chain polyunsaturated n–3 (ω-3) fatty acids (aka omega-3 fatty acids) found in oily fish like salmon, herring, mackerel, and tuna, and in predatory fish that eat oily fish (e.g. swordfish, shark, tuna). DHA and EPA are also found in algae and in high amounts in flax seeds, chia seeds, hemp seeds, and walnuts.
In our body, DHA and EPA have a number of roles. EPA primarily acts as a precursor in the synthesis of prostaglandins and leukotrienes, which are molecules involved in inflammation and immune function. Meanwhile, DHA primary acts as a structural component in the cerebral cortex, skin, and retina. But, while both EPA and DHA are important fatty acids, neither are classified as “essential” fatty acids because our body can synthesise them in adequate amounts to maintain normal function, but only if you have an adequate dietary source of another omega-3 fatty acid, called alpha-linolenic acid (aka ALA, one of the two essential fatty acids in humans along with linoleic acid). Alpha-linolenic acid is found in chia seeds and flax seeds but, in humans, the synthesis efficiency of alpha-linolenic acid to EPA and DHA is rather poor, hence the dietary recommendation to consume foods containing ALA, DHA and EPA.
Because of the abundance of omega-3 fatty acids in several foods, it is likely that you’ve been getting your daily fix of omega-3s for years. And, because we are under the perilous dietary fallacies of our elders, you might have been subjected to that spoonful of cod liver oil* your mum used to trick you into eating every morning as a kid. (*Note: cod liver oil is not only rich in DHA and EPA but also vitamins A and E; and, it tastes like sh*t — I hated my mum 40 years ago.) But, since many folks’ diet is subpar and since many folks probably don’t eat fish or seeds, it is also likely that many folks aren’t getting any DHA, EPA, or alpha-linolenic acid (ALA) in their diet. Therefore, omega-3s and fish oils have become very popular dietary supplements and supplementation may be necessary for people whose diet lacks foods containing DHA, EPA, and ALA. Beyond that, it is very difficult to ignore brand marketing campaigns regularly plugging fish oil products for athlete recovery and/or performance — on that note, the important question is…
Do omega-3s (DHA and EPA) or fish oils improve performance or recovery — what do the systematic reviews say?
Please note that this summary is about exercise performance and/or recovery, not disease risk, prevention, or treatment. If you want to go deep on the effects of omega-3s (DHA and EPA) or fish oils on general health, please check out examine.com/supplements/fish-oil/ because Examine.com go deep on dietary supplements from a health perspective and I consider it a carefully-researched and trusted source. (NOTE: For full disclosure, I started working as a researcher for Examine in October 2022.)
The adequate requirement for dietary intake of EPA, DHA, ALA, and linoleic acid is unknown but the adequate intake for adults, based on population averages, is 250 milligrams (mg) per day for DHA+EPA (source: Dietary Reference Values for the EU). Fish oils are generally safe to consume. That said, oily fish and fish oils can be contaminated with heavy metals and fat-soluble pollutants but the benefits of fish intake are generally considered to far outweigh the potential risks. Also note that liver-derived fish oil contains vitamin A, which can be toxic in high doses so there is an upper limit of ~3000 micrograms (μg) per day in adults (source: Dietary Reference Values for the EU).
For dietary reference values (DRVs) in Europe, consult efsa.europa.eu/drvs/index.htm. Or click here to view all DRVs for vitamins, minerals, and fatty acids (DHA, EPA, and ALA). And, to search for the vitamin/mineral content of specific foods, consult fdc.nal.usda.gov/fdc-app.html.
In younger adults aged 18 to 55, omega-3 (DHA + EPA) supplementation does not improve muscle hypertrophy, muscle strength or skeletal muscle biomarkers of inflammation and muscle damage beyond those obtained by strength training. There is no current systematic review on endurance performance. But…
Omega-3 (DHA + EPA) supplementation does improve recovery of muscle soreness (self-reported feelings of soreness) and range of motion following exercise-induced muscle damage.
In older adults (55 years +), omega-3 (DHA + EPA) supplementation does not affect walking performance or upper-body strength but may increase lower-body strength and lower-body functional performance (get-up-and-go & sit-to-stand tests).
The effects of omega-3 supplementation in older adults are found in the presence and absence of resistance training, suggesting that older adults who cannot or do not exercise may benefit from omega-3 supplementation. But…
The range of omega-3 doses used is large — e.g. EPA ranging from 300 to 2400 mg/d and DHA from 400 to 1500 mg/d — and there is large between-study heterogeneity (variability) and pooling of studies using various blends of supplements (e.g. fish oils, DHA, EPA, ALA, and linoleic acid). Furthermore, there is evidence of publication bias toward only positive findings being reported.
It is also currently unclear whether people enrolled in the studies had a prior omega-3 deficiency (diet lacking omega-3-containing foods) upon enrollment in the studies. If this was the case, then the omega-3 supplement would simply be replacing what is missing.
More high-quality randomised controlled trials are needed and dose responses need to be clarified.
If you choose to use omega-3s (DHA and EPA) or fish oils, a reasonable dose is:
~250 milligrams (mg) per day for combined EPA and DHA. A 1 gram (or 1000 milligrams; mg) fish oil supplement typically contains ~300 mg of combined EPA and DHA. But always check the nutritional label of your fish oil supplement. Note: this is based on the estimated adequate requirement for dietary intake (source: Dietary Reference Values for the EU). The effective dose for recovery and performance has not yet been clearly defined by research.
This is equivalent to ~2 × 100-gram portions of cooked salmon per week (source: fdc.nal.usda.gov/fdc-app.html) or ~1 to 2 grams of dried chia seeds per day (source: fdc.nal.usda.gov/fdc-app.html).
Taking more doesn’t necessarily mean a bigger effect and dietary supplements like omega-3s and fish oils are intended as a supplement to, not a replacement for, real food.
To conclude…
There is some evidence to suggest that a daily omega-3 or fish oil supplement might help alleviate feelings of muscle soreness and restore range of motion following muscle-damaging exercise. The effect size is small to moderate. If alleviating feelings of muscle soreness and restoring range of motion after muscle-damaging exercise is of benefit to you, then supplementation may be advised; but, note that trying to blunt soreness and inflammation after exercise may also blunt the very processes that are causing adaptations to exercise.
The evidence also suggests that a daily omega-3 or fish oil supplement is likely to improve lean mass and muscle strength in older-aged adults (effect size is trivial to small) but not in younger adults. That said, the quality of evidence is mixed with some high risk of bias — more h high-quality randomised controlled trials are needed!
As an athlete, a daily omega-3 or fish oil supplement is highly unlikely to improve your performance unless you are of older age (>~55 years) and/or deficient in DHA and EPA.
If your habitual diet is deficient in foods containing DHA, EPA, or ALA (e.g. oily fish, seeds, etc) then a supplement may also be advised, under the direction of your doctor. As with any supplement, “taking more does not equal a bigger effect” and a dietary supplement is intended as a supplement to, not a replacement for, real food — learn how to establish a healthy eating pattern at veohtu.com/healthyeatingpattern. For example, omega-3s are found in fish and seeds etc. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining omega-3s (DHA and EPA) and fish oils for performance and recovery.
Here is the list of systematic reviews I have summarised above.
Effects of Omega-3 Supplementation Alone and Combined with Resistance Exercise on Skeletal Muscle in Older Adults: A Systematic Review and Meta-Analysis. Stephen M Cornish Dean M Cordingley, Keely A Shaw, Scott C Forbes, Taylor Leonhardt, Ainsley Bristol, Darren G Candow, Philip D Chilibeck. Nutrients (2022)
The effect of long chain omega-3 polyunsaturated fatty acids on muscle mass and function in sarcopenia: A scoping systematic review and meta-analysis. Julia K Bird, Barbara Troesch, Ines Warnke, Philip C Calder. Clin Nutr ESPEN (2021)
Effect of omega-3 fatty acids supplementation on indirect blood markers of exercise-induced muscle damage: Systematic review and meta-analysis of randomized controlled trials. Gao Xin, Hesam Eshaghi. Food Sci Nutr (2021)
N-3 PUFA as an ergogenic supplement modulating muscle hypertrophy and strength: a systematic review. López-Seoane J, Martinez-Ferran M, Romero-Morales C, Pareja-Galeano H. Crit Rev Food Sci Nutr (2021).
The effect of fish oil supplementation on the promotion and preservation of lean body mass, strength, and recovery from physiological stress in young, healthy adults: a systematic review. Heileson JL, Funderburk LK. Nutr Rev (2020).
Are There Benefits from the Use of Fish Oil Supplements in Athletes? A Systematic Review. Lewis NA, Daniels D, Calder PC, Castell LM, Pedlar CR. Adv Nutr (2020).
Omega-3 Polyunsaturated Fatty Acid Supplementation for Reducing Muscle Soreness after Eccentric Exercise: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Zheng-Tao Lv, Jin-Ming Zhang, Wen-Tao Zh. Biomed Res Int (2020)
Response to exercise in older adults who take supplements of antioxidants and/or omega-3 polyunsaturated fatty acids: A systematic review. Rosario Pastor, Josep A Tur. Biochem Pharmacol (2020)
Effects of Omega-3 Supplementation Alone and Combined with Resistance Exercise on Skeletal Muscle in Older Adults: A Systematic Review and Meta-Analysis. Stephen M Cornish Dean M Cordingley, Keely A Shaw, Scott C Forbes, Taylor Leonhardt, Ainsley Bristol, Darren G Candow, Philip D Chilibeck. Nutrients (2022)
The effect of long chain omega-3 polyunsaturated fatty acids on muscle mass and function in sarcopenia: A scoping systematic review and meta-analysis. Julia K Bird, Barbara Troesch, Ines Warnke, Philip C Calder. Clin Nutr ESPEN (2021)
Effect of omega-3 fatty acids supplementation on indirect blood markers of exercise-induced muscle damage: Systematic review and meta-analysis of randomized controlled trials. Gao Xin, Hesam Eshaghi. Food Sci Nutr (2021)
N-3 PUFA as an ergogenic supplement modulating muscle hypertrophy and strength: a systematic review. López-Seoane J, Martinez-Ferran M, Romero-Morales C, Pareja-Galeano H. Crit Rev Food Sci Nutr (2021).
The effect of fish oil supplementation on the promotion and preservation of lean body mass, strength, and recovery from physiological stress in young, healthy adults: a systematic review. Heileson JL, Funderburk LK. Nutr Rev (2020).
Are There Benefits from the Use of Fish Oil Supplements in Athletes? A Systematic Review. Lewis NA, Daniels D, Calder PC, Castell LM, Pedlar CR. Adv Nutr (2020).
Omega-3 Polyunsaturated Fatty Acid Supplementation for Reducing Muscle Soreness after Eccentric Exercise: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Zheng-Tao Lv, Jin-Ming Zhang, Wen-Tao Zh. Biomed Res Int (2020)
Response to exercise in older adults who take supplements of antioxidants and/or omega-3 polyunsaturated fatty acids: A systematic review. Rosario Pastor, Josep A Tur. Biochem Pharmacol (2020)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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Vitamin D is a fat-soluble vitamin that primarily regulates calcium (and phosphate and magnesium) metabolism to facilitate bone growth and maintain bone health. Vitamin D deficiency causes bone irregularities, which in the extreme can cause rickets (impaired bone growth) in children and osteomalacia (soft bones & weak muscles) and osteoporosis (low bone density & fractures) in adults. Our skin cells can synthesise cholecalciferol (aka vitamin D3) when our skin is exposed to sunlight (UV-B radiation), but we also obtain vitamin D3 in our diet from foods like egg yolks, liver, oily fish (salmon, mackerel, sardines), and cod liver oil, as well as from foods that have been “fortified” with vitamin D3 (like some breakfast cereals and milk).
But vitamin D synthesis and metabolism are super complex and confusing. When synthesised in the skin or eaten, cholecalciferol (vitamin D3) travels in the blood to the liver where it is “hydroxylated” (a hydroxyl group, —OH, is added) to produce a prohormone called calcifediol (aka 25-hydroxyvitamin D aka 25(OH)D). Calcifediol then leaves the liver and travels in the blood to your kidneys, where it is further “hydroxylated” to produce the active “hormonal” form of vitamin D, called calcitriol (1,25(OH)2D). Calcitriol is released by the kidney into the blood and then acts like a hormone, binding to vitamin D receptors on various tissues in the body to cause its effects. Furthermore, calcitriol is also produced in some immune cells where it plays a role in innate immunity.
Phew!
The prevalence of vitamin D deficiency is widely studied and, likely due to poor dietary habits and low exposure to direct sunlight, is actually pretty high — ~20% in Australia, ~68% across 5 South-East Asian countries, ~40% in the USA, ~34% in Scotland, and ~18% across Africa, etc. But, it is important to note that prevalence estimates massively vary by season.
Due to the high prevalence of vitamin D deficiency, vitamin D is commonly prescribed as a dietary supplement to bring bodily levels of cholecalciferol (aka vitamin D3) back up to normal. However, vitamin D supplements are also freely available over the counter, which creates a problem because vitamin D is fat-soluble and, therefore, is stored in the body and can be toxic when supplemented in high amounts. Interestingly, the 2013-14 NHANES (National Health and Nutrition Examination Survey) survey found that 18% of American adults exceeded 1000 IU (international units) of supplemental vitamin D per day, which is more than twice the US RDA (recommended daily amount), and that 3% took more than 4000 IU per day, which exceeds the upper tolerable limit and, therefore, increases the risk of adverse effects. The 1999-2000 NHANES survey found that just 0.3% and 0.1% of the population exceeded 1000 or 4000 IUs daily, indicating that intentional (and excessive) vitamin D supplementation has increased dramatically.
Vitamin D has many physiological roles and is essential for maintaining health. Systematic reviews and meta-analyses have examined the association of blood concentrations of the vitamin D prohormone, calcifediol (or 25(OH)D) with various health outcomes — low 25(OH)D is associated with higher all-cause and cardiovascular-related risk of dying (aka mortality; see here & here), and a greater risk of severe infections (sepsis), cardiovascular disease, type 2 diabetes (see here & here), gestational diabetes, and dementia. But, associations do not prove that low vitamin D is causal in disease nor do they prove that vitamin supplementation will prevent or treat disease. Fortunately, systematic reviews and meta-analyses have determined the effect of vitamin D supplementation on disease…
Vitamin D supplementation doesn’t lower the risk of death from any cause (aka all-cause mortality) in the general population (see here, here, & here) nor does it lower the risk of cardiovascular disease (CVD) or CVD end-points (myocardial infarction, stroke, CVD mortality). But, Vitamin D supplementation may lower cancer-related risk of death, all-cause mortality in elderly folks, risk of diabetes in folks with prediabetes (see here, here, & here), and may help improve blood glucose control in patients with type 2 diabetes (see here & here).
NOTE: At this time, the effect of vitamin D supplementation on cognitive decline in dementia has not been systematically reviewed.
To summarise the above, vitamin D deficiency is associated with disease risk and supplementation may reduce the risk for some conditions. But, importantly, several of the meta-analyses found that the effects of vitamin D supplementation were only (or most) pronounced in folks who had vitamin D deficiency (blood 25-(OH)D <30 ng/ml) — i.e. supplementation was simply bringing vitamin D back to healthy levels.
Vitamin D has become a very popular dietary supplement and supplementation can be necessary for people who have a vitamin D deficiency (caused by a lack of daily sunlight, a dietary lack of foods containing vitamin D, or an irregularity of vitamin D metabolism). As of 2020, Public Health England, the health authority in the cloudy and sunlight-deficient UK, now recommends that all people who don’t obtain sufficient vitamin D in their diet should take a vitamin D supplement in the autumn and winter months (when sunlight is nonexistent). If you suspect you have a vitamin D deficiency, consult your doctor who can assess your vitamin D status by ordering a blood test for 25(OH)D (25-hydroxyvitamin D). A plasma concentration of <30 ng/ml indicates deficiency and your doctor may prescribe you a vitamin D supplement based on your results.
NOTE: you will see many names assigned to a vitamin D blood test — a 25-OH vitamin D blood test, cholecalciferol (vitamin D3) test, ergocalciferol (vitamin D2) test, calcidiol test, vitamin D2 test, or vitamin D3 test — which all assess a different aspect of vitamin D metabolism.
Since vitamin D receptors and vitamin D-related metabolites have been discovered in skeletal muscle and given that vitamin D regulates calcium metabolism and calcium is essential for muscle contraction, it is not absurd to hypothesise a role for vitamin D in muscle function. Indeed, a 2013 systematic review found that the blood concentration of 25(OH)D (25-hydroxyvitamin D, aka calcifediol) is associated with muscle strength. Since vitamin D deficiency is not rare, it is also not absurd to hypothesise that vitamin D supplementation may help performance — no doubt you have noticed the outbreak of brand marketing campaigns regularly plugging vitamin D products for athlete recovery and/or performance. So, the important question is…
Does vitamin D improve performance or recovery — what do the systematic reviews say?
Please note that this summary is about exercise performance and/or recovery, not disease risk, prevention, or treatment. If you want to go deep on the effects of vitamin D on general health, please check out examine.com/supplements/vitamin-d because Examine.com go deep on dietary supplements from a health perspective and I consider it a carefully-researched and trusted source. (NOTE: For full disclosure, I started working as a researcher for Examine in October 2022.)
The adequate requirement for dietary intake of vitamin D is unknown but the adequate intake for adults, based on population averages, is 15 micrograms (μg) per day (~600 IU/day) for vitamin D in the form of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Vitamin D is generally safe to consume but there is a tolerable upper intake level of 100 μg per day (~4000 IU/day). Source: Dietary Reference Values for the EU.
For dietary reference values (DRVs) in Europe, consult efsa.europa.eu/drvs/index.htm. Or click here to view all DRVs for vitamins, minerals, and fatty acids (DHA, EPA, and ALA). And, to search for the vitamin/mineral content of specific foods, consult fdc.nal.usda.gov/fdc-app.html.
In postmenopausal women, daily vitamin D supplementation (~800 to 1,000 IU per day of cholecalciferol, aka vitamin D3) without daily exercise does not improve functional performance (timed up-and-go) but can induce small increases in hand-grip strength, a biomarker of whole body muscle strength. However, this effect is most pronounced in women over 60 years of age, women who do not take calcium supplementation, and women with vitamin D deficiency (blood 25(OH)D <30 ng/ml).
In older adults (aged 50 or older), daily vitamin D supplementation (~800 to 1,000 IU per day of cholecalciferol) without daily exercise does not improve muscle strength, functional performance (timed up-and-go), or lean body mass (a biomarker for muscle mass). But…
In older adults, daily vitamin D supplementation combined with regular strength training may improve muscle strength beyond strength training alone. More high-quality studies are needed in this area.
In younger adults (~18 to 50 years old), the effects of daily vitamin D supplementation on muscle strength are trivial and there are no effects on muscle mass or muscle power. But, greater benefits are seen in folks with vitamin D deficiency (blood 25(OH)D <30 ng/ml). More high-quality studies are needed in this area.
In adults of all ages, daily vitamin D supplementation has a moderate effect size on preventing the rise in blood creatine kinase levels after exercise-induced muscle damage but it does not help prevent the impairment in muscle strength following exercise-induced muscle damage. Higher-quality RCTs are required to tackle this topic.
In athletes, daily vitamin D supplementation combined with regular training does not improve performance. Some data shows beneficial effects on lower-limb but not upper-limb muscle strength and some data shows beneficial effects on athletes who train indoors. But, between-study heterogeneity (variability) in study designs is large and more high-quality studies are needed, especially examining athletes with and without vitamin D deficiency and athletes located in different geographical latitudes and climates (with different UV exposure).
If you choose to use vitamin D, a reasonable dose is:
~15 micrograms (μg) or ~600 international units (IU) of cholecalciferol (vitamin D3) every day. Note: this is based on effective doses used in research.
This is equivalent to ~30-minutes of skin exposure to the sun each day.
Sometimes the amount of vitamin D is expressed in micrograms (μg) or International Units (IU) — 1 μg of vitamin D is equal to 40 IU. Therefore, a reasonable daily dose of 15 μg/day is equal to 600 IU/day and the tolerable upper intake level of 100 μg/day is equal to 4000 IU/day.
Taking more doesn’t necessarily mean a bigger effect and dietary supplements like vitamin D are intended as a supplement to, not a replacement for, real food.
To conclude…
The current evidence suggests that taking vitamin D is highly unlikely to boost your performance if you have healthy vitamin D levels. If you have a vitamin D deficiency (blood 25OHD <30 ng/ml) and/or are of older age and combining supplementation with strength training, vitamin D is likely to help increase muscle strength — the effect size is small to moderate. But, this might simply be restoring your performance back to the level it would be if you had healthy blood vitamin D levels. If you suspect you have a vitamin D deficiency because of insufficient intake of vitamin D-containing foods or a lack of exposure to sunlight, consult your doctor for a blood test and subsequent supplementation decisions can be made with their advice. Self-diagnosis is never wise and mega-dosing with supplements is not recommended. As with any supplement, “taking more does not equal a bigger effect” and a dietary supplement is intended as a supplement to, not a replacement for, real food — learn how to establish a healthy eating pattern at veohtu.com/healthyeatingpattern. If you choose to supplement, only choose supplements that have been independently tested (e.g. Informed Sport). And, remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”.
Full list of systematic reviews examining vitamin D for performance and recovery.
Here is the list of systematic reviews I have summarised above.
Vitamin D Supplementation Improves Handgrip Strength in Postmenopausal Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Jia-Li Zhang, Christina Chui-Wa Poon, Man-Sau Wong, Wen-Xiong Li, Yi-Xun Guo, Yan Zhang. Front Endocrinol (2022)
Effect of vitamin D monotherapy on indices of sarcopenia in community-dwelling older adults: a systematic review and meta-analysis. Konstantinos Prokopidis, Panagiotis Giannos, Konstantinos Katsikas Triantafyllidis, Konstantinos S Kechagias, Jakub Mesinovic, Oliver C Witard, David Scott. J Cachexia Sarcopenia Muscle (2022)
Effects of Vitamin D in Post-Exercise Muscle Recovery. A Systematic Review and Meta-Analysis. Hugo J Bello, Alberto Caballero-García, Daniel Pérez-Valdecantos, Enrique Roche, David C Noriega, Alfredo Córdova-Martínez. Nutrients (2021)
The Optimal Strategy of Vitamin D for Sarcopenia: A Network Meta-Analysis of Randomized Controlled Trials. Shih-Hao Cheng, Kee-Hsin Chen, Chiehfeng Chen, Woei-Chyn Chu, Yi-No Kang. Nutrients (2021)
The effects of vitamin D supplementation on muscle strength and mobility in postmenopausal women: a systematic review and meta-analysis of randomised controlled trials. M Abshirini, H Mozaffari, H Kord-Varkaneh, M Omidian, M C Kruger. J Hum Nutr Diet (2020)
Effect of vitamin D supplementation on upper and lower limb muscle strength and muscle power in athletes: A meta-analysis. Lin Zhang, Minghui Quan, Zhen-Bo Cao. PLoS One (2019)
The effect of combined resistance exercise training and vitamin D3 supplementation on musculoskeletal health and function in older adults: a systematic review and meta-analysis. Antoniak AE, Greig CA. BMJ Open (2017)
Vitamin D supplementation and its influence on muscle strength and mobility in community-dwelling older persons: a systematic review and meta-analysis. H Rosendahl-Riise, U Spielau, A H Ranhoff, O A Gudbrandsen, J Dierkes. J Hum Nutr Diet (2017) — This article has a correction at ncbi.nlm.nih.gov/pmc/articles/PMC6885933/.
Effects of Vitamin D Supplementation on Serum 25-Hydroxyvitamin D Concentrations and Physical Performance in Athletes: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Forough Farrokhyar, Gayathri Sivakumar, Katey Savage, Alex Koziarz, Sahab Jamshidi, Olufemi R Ayeni, Devin Peterson, Mohit Bhandari. Sports Med (2017)
Effects of Vitamin D Supplementation on Muscle Strength in Athletes: A Systematic Review. Chien-Ming Chiang, Ahmed Ismaeel, Rachel B Griffis, Suzy Weems. J Strength Cond Res (2017)
A Systematic Review of the Role of Vitamin D on Neuromuscular Remodelling Following Exercise and Injury. Minshull C, Biant LC, Ralston SH, Gleeson N. Calcif Tissue Int (2016)
Effects of vitamin D supplementation on upper and lower body muscle strength levels in healthy individuals. A systematic review with meta-analysis. Peter B Tomlinson, Corey Joseph, Manuela Angioi. J Sci Med Sport (2015)
The effects of vitamin D on skeletal muscle strength, muscle mass, and muscle power: a systematic review and meta-analysis of randomized controlled trials. Charlotte Beaudart, Fanny Buckinx, Véronique Rabenda, Sophie Gillain, Etienne Cavalier, Justine Slomian, Jean Petermans, Jean-Yves Reginster, Olivier Bruyère. J Clin Endocrinol Metab (2014)
Effect of vitamin D supplementation on muscle strength, gait and balance in older adults: a systematic review and meta-analysis. Muir SW, Montero-Odasso M. J Am Geriatr Soc (2011)
Effect of vitamin D supplementation on muscle strength: a systematic review and meta-analysis. K A Stockton, K Mengersen, J D Paratz, D Kandiah, K L Bennell. Osteoporos Int (2011)
Vitamin D-related changes in physical performance: a systematic review. C Annweiler, A M Schott, G Berrut, B Fantino, O Beauchet. Journal (2009)
Vitamin D and cognitive performance in adults: a systematic review. C Annweiler, G Allali, P Allain, S Bridenbaugh, A-M Schott, R W Kressig, O Beauchet. Eur J Neurol (2009)
Effects of vitamin D supplementation on strength, physical performance, and falls in older persons: a systematic review. Nancy K. Latham, Craig S. Anderson, Ian R. Reid. J Am Geriatr Soc (2003)
Vitamin D Supplementation Improves Handgrip Strength in Postmenopausal Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Jia-Li Zhang, Christina Chui-Wa Poon, Man-Sau Wong, Wen-Xiong Li, Yi-Xun Guo, Yan Zhang. Front Endocrinol (2022)
Effect of vitamin D monotherapy on indices of sarcopenia in community-dwelling older adults: a systematic review and meta-analysis. Konstantinos Prokopidis, Panagiotis Giannos, Konstantinos Katsikas Triantafyllidis, Konstantinos S Kechagias, Jakub Mesinovic, Oliver C Witard, David Scott. J Cachexia Sarcopenia Muscle (2022)
Effects of Vitamin D in Post-Exercise Muscle Recovery. A Systematic Review and Meta-Analysis. Hugo J Bello, Alberto Caballero-García, Daniel Pérez-Valdecantos, Enrique Roche, David C Noriega, Alfredo Córdova-Martínez. Nutrients (2021)
The Optimal Strategy of Vitamin D for Sarcopenia: A Network Meta-Analysis of Randomized Controlled Trials. Shih-Hao Cheng, Kee-Hsin Chen, Chiehfeng Chen, Woei-Chyn Chu, Yi-No Kang. Nutrients (2021)
The effects of vitamin D supplementation on muscle strength and mobility in postmenopausal women: a systematic review and meta-analysis of randomised controlled trials. M Abshirini, H Mozaffari, H Kord-Varkaneh, M Omidian, M C Kruger. J Hum Nutr Diet (2020)
Effect of vitamin D supplementation on upper and lower limb muscle strength and muscle power in athletes: A meta-analysis. Lin Zhang, Minghui Quan, Zhen-Bo Cao. PLoS One (2019)
The effect of combined resistance exercise training and vitamin D3 supplementation on musculoskeletal health and function in older adults: a systematic review and meta-analysis. Antoniak AE, Greig CA. BMJ Open (2017)
Vitamin D supplementation and its influence on muscle strength and mobility in community-dwelling older persons: a systematic review and meta-analysis. H Rosendahl-Riise, U Spielau, A H Ranhoff, O A Gudbrandsen, J Dierkes. J Hum Nutr Diet (2017) — This article has a correction at ncbi.nlm.nih.gov/pmc/articles/PMC6885933/.
Effects of Vitamin D Supplementation on Serum 25-Hydroxyvitamin D Concentrations and Physical Performance in Athletes: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Forough Farrokhyar, Gayathri Sivakumar, Katey Savage, Alex Koziarz, Sahab Jamshidi, Olufemi R Ayeni, Devin Peterson, Mohit Bhandari. Sports Med (2017)
Effects of Vitamin D Supplementation on Muscle Strength in Athletes: A Systematic Review. Chien-Ming Chiang, Ahmed Ismaeel, Rachel B Griffis, Suzy Weems. J Strength Cond Res (2017)
A Systematic Review of the Role of Vitamin D on Neuromuscular Remodelling Following Exercise and Injury. Minshull C, Biant LC, Ralston SH, Gleeson N. Calcif Tissue Int (2016)
Effects of vitamin D supplementation on upper and lower body muscle strength levels in healthy individuals. A systematic review with meta-analysis. Peter B Tomlinson, Corey Joseph, Manuela Angioi. J Sci Med Sport (2015)
The effects of vitamin D on skeletal muscle strength, muscle mass, and muscle power: a systematic review and meta-analysis of randomized controlled trials. Charlotte Beaudart, Fanny Buckinx, Véronique Rabenda, Sophie Gillain, Etienne Cavalier, Justine Slomian, Jean Petermans, Jean-Yves Reginster, Olivier Bruyère. J Clin Endocrinol Metab (2014)
Effect of vitamin D supplementation on muscle strength, gait and balance in older adults: a systematic review and meta-analysis. Muir SW, Montero-Odasso M. J Am Geriatr Soc (2011)
Effect of vitamin D supplementation on muscle strength: a systematic review and meta-analysis. K A Stockton, K Mengersen, J D Paratz, D Kandiah, K L Bennell. Osteoporos Int (2011)
Vitamin D-related changes in physical performance: a systematic review. C Annweiler, A M Schott, G Berrut, B Fantino, O Beauchet. Journal (2009)
Vitamin D and cognitive performance in adults: a systematic review. C Annweiler, G Allali, P Allain, S Bridenbaugh, A-M Schott, R W Kressig, O Beauchet. Eur J Neurol (2009)
Effects of vitamin D supplementation on strength, physical performance, and falls in older persons: a systematic review. Nancy K. Latham, Craig S. Anderson, Ian R. Reid. J Am Geriatr Soc (2003)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
This tool is free. Please help keep it alive by buying me a beer:
Buy me a beer. Want free info like this in your inbox? Sign up here:
In the 90s, I moshed my socks off to Brian Molko’s melodic voice at many a Placebo gig. He taught me one thing: placebos rock! Dad jokes aside, a placebo is sometimes used in clinical trials and usually takes the form of a sugar pill, a saline (salt water) injection (like saline), or sham (fake) surgery (where the surgeon opens you up, has some lunch, stitches you back up, and pretends they did a procedure on you). Theoretically, a placebo is supposed to have no effect on whatever variable of interest you are studying.
In a randomised controlled trial, there is a treatment group and a control group. Sometimes, the control group is given something that resembles the treatment to prevent participants from knowing which group they are in — this something is called a “placebo” and we’d call this type of trial a placebo-controlled clinical trial. If the variable of interest improves in the placebo-controlled group we might think that the placebo has had an effect. But, to make that conclusion, we would need an additional non-placebo control group to know whether the placebo has improved the variable of interest more than doing nothing at all — it could be that the disease naturally improves with time. When studies have a placebo-controlled group and a non-placebo control group, if the change in the variable of interest in the placebo group is larger than the change in the non-placebo group, we can conclude that there has been a placebo effect (and Brian Molko can sing about it). On the flip side, if the variable of interest worsens in the placebo-controlled group (and more so than in the non-placebo group), we conclude that there has been a nocebo effect (i.e. a negative or detrimental placebo effect).
Imagine this scenario:
You have an important race today and your coach gives you a supplement to take that they know is not proven to enhance performance. You don’t know what it is or what its effect is supposed to be but, because you want to win and you trust your coach, you take it. During the race, you feel like a monster — strong, fast, and highly motivated. You win! In your post-mortem of the race, you think, without a doubt, that the supplement made you win. Your mother says it was a coincidence. Your coach says you had trained for months, had been setting PBs, and were well-prepared and ready for a great race — you were always going to win.
If you are right, then this supplement could be called a placebo and your race win could be called a placebo effect. But, because you had a positive expectation of a performance-enhancing effect, the effect of the placebo could also be called a belief effect. But, a positive expectation of an effect is not always required for a placebo effect and having a positive expectation of an effect can even enhance the placebo effect. The important thing to learn is that while your experiences shape your beliefs, your experiences (i.e. you won after taking a supplement) must be combined with data (your training had been great, you’d set PBs all season, and were in the shape of your life) to accurately inform your belief. The other important thing to learn is that “you are the only person responsible for what goes in your body” — never take candy from
Now, that was just hypothetical — you’re probably wondering, does the placebo effect exist?
Several systematic reviews have found evidence for the placebo effect in a range of diseases in studies where participants are blinded to whether they are receiving a placebo or the real treatment. A couple of recent systematic reviews (see here & here) also find evidence for the placebo effect on a range of diseases when an “open-label” placebo (participants know they’re receiving a placebo) is compared to a non-placebo (no treatment) intervention, with summary effect sizes of 0.88 (a large effect; 95% confidence interval 0.62 to 1.14) and 0.72 (a moderate effect; 95%CI 0.39 to 1.05).
Woah!
But… These findings should be interpreted with caution because, in longitudinal studies (when the variable of interest is measured before and after several days/weeks/months/years), as I said earlier, the disease might naturally improve with time without real treatment. (Putting that in the context of exercise, your performance might improve while training with a supplement but it might also improve with training alone.) Furthermore, most studies do not have non-placebo control group. Plus, there are only a few small “open label” trials and participants weren’t blinded to the placebo vs. no treatment groups and, in many cases, participants received “positive messages” in addition to the open-label placebos before being asked about their feelings of pain or discomfort. E.g. “This will make you feel better.” ... … “How are you feeling?”.
Sometimes doctors prescribe placebos (without the patient’s knowledge) instead of therapeutic drugs to help “treat” a condition. As is probably obvious, from an ethical stance, placebos are a touchy subject — patients have a right to know what they’re receiving rather than being “deceived”. Furthermore, since the “belief effect” (the extent to which a person believes the treatment will work) can also influence the effectiveness of interventions, it could be argued that instead of deceptively-prescribing placebos (in place of therapeutic drugs), doctors could use the placebo effect and/or the belief effect to enhance the therapeutic effect of a drug — if a patient believes the treatment will help them, perhaps they’ll be more motivated to adhere to it. But, I’m going a little off-piste and away from exercise performance.
In research, it is very difficult for scientists to get “deception” studies approved by ethical review boards. But there are some fun examples. In a 2015 study from Ramzy et al., trained 10 km runners received no treatment or daily injections of “OxyRBX”, which they were told had the same effects as EPO (a red blood cell-boosting hormone that improves endurance performance). Before and after 7-days of treatment/no treatment, runners completed a 3 km race. On average, athletes in the OxyRBX group improved their 3 km time by 9.73 seconds (95%CI 5.14 to 14.33 seconds) whereas untreated athletes ran 1.82 s faster (95%CI 2.77 s slower to 6.41 s faster; group-change comparison P=0.02). OxyRBX-treated runners also reported less physical effort, increased motivation, and improved recovery. This is an example of a placebo effect, probably caused by a belief effect.
That’s kinda fun but now consider this thought experiment:
A study tests the hypothesis that a caffeine-containing beverage improves 3 km running performance in well-trained runners. The runners complete the 3 km time trial four times in a randomised cross-over design, at the same time of day following a 5-day period of identical nutrition, sleep, and training. In each trial, runners are given 250 mL of cold fluid to ingest 30-mins prior to the time trial — the fluid is either water (no treatment), coffee (treatment), decaf coffee (placebo 1), and the same type of decaf coffee (placebo 2). The runners do not see the drinks being prepared and cannot see the drinks until they sip from them, but they obviously taste that water is not coffee. However, they cannot taste the difference between the coffee and the decaf. But, in one of the decaf coffee trials, runners are told that “This coffee has a lot of caffeine and will massively improve your performance today.” — this is the “belief” trial. When the study is finished and analysed, the data show that 3 km performance was equally faster in the coffee and the “belief” decaf trials than in the water and decaf trials, which were not different from one another. The researchers conclude that there was no placebo effect of decaf placebo 1 but there was a placebo effect (or belief effect) of decaf placebo 2 — decaf coffee gave the same performance-enhancing boost as coffee when runners were told it would.
Does the placebo effect improve recovery and/or performance — what do the systematic reviews say?
The placebo (or nocebo) effect is a difficult thing to assess. The placebo must be indistinguishable from the actual treatment, a non-placebo control group must also be included, studies must control for participants’ knowledge of the effect of the treatment and/or placebo, and studies must control for the participant correctly guessing whether they have received treatment or not. These things are not always possible and are sometimes impossible (e.g. you cannot blind a person from doing a type of exercise; similarly, you can’t blind someone from being in a sauna).
In studies with a placebo control and a non-placebo control, the placebo effect explains ~50% of the beneficial effect of exercise training on cognitive function and psychological outcomes inc. anxiety, depression, mood, etc (Lindheimer et al: placebo effect size = 0.20, 95%CI -0.02 to 0.41; exercise effect size = 0.37, 95%CI 0.11 to 0.63). But, more high-quality randomised controlled trials are needed to bolster these findings and none of these studies was on athletes.
When pooling several nutritional (inc. caffeine, beta-alanine, sodium bicarbonate, and anabolic steroids) and mechanical (inc. electrical muscle stimulation, kinesiology tape, blood flow restriction, magnetic bands, and cold water immersion) interventions in “deception” studies where participants are led to believe they’re receiving a beneficial treatment, there are small to moderate placebo effects (effect size = 0.36) and nocebo effects (effect size = 0.37) on sports performance. But, the methodological quality of the studies is generally poor so more high-quality randomised controlled trials are needed.
When specifically assessing caffeine and buffering supplements (e.g. sodium bicarbonate) in blinded studies where participants don’t know if they’re on placebo or treatment, the placebo has a trivial (tiny) but meaningful (95%CI does not cross zero) effect on (effect size = 0.09, 95%CI 0.01 to 0.17) vs. the non-placebo-control while the actual treatment has a small effect (effect size = 0.37, 95%CI 0.20 to 0.56) vs. no treatment on running and cycling time-to-exhaustion and time-trial performance. This means that ~25% of the performance-enhancing effect of caffeine or buffers is explained by a placebo effect. Therefore…
Since placebo effects are real and have a small effect, it would be prudent for an athlete (and an athlete’s support team) to try to maximise the placebo effect of a proven treatment by encouraging belief in its effectiveness.
If you choose to use the placebo effect, a reasonable approach is to:
Instil belief in the approaches you use and in the people you work with. Note: this is based on effective doses used in research.
But be aware that psychological belief in an approach can be a replacement for science EXCEPT when science shows that the approach has detrimental physiological effects. For example, many athletes claim that they “recover better” when using ice baths (cold water immersion) after exercise. But, while cold water immersion may reduce feelings of soreness and improve feelings of recovery in the short-term, in the long-term, daily post-exercise cold water immersion has been shown to blunt training adaptations.
To conclude…
There is some evidence to suggest that using the placebo effect is likely to boost your performance — the effect size is trivial to small. But, remember that the placebo effect does not make an athlete — the placebo effect does not replace training and placebo effects are not additive. I.e. using and believing in 5 supplements that don’t have proven ergogenic effects won't give you 5-times the benefit. Instead, it will give you 5 more factors that cost money and time and could return a positive doping test. This is stress and stress is the antithesis of the recovery and adaptation required for high performance. Yes, the placebo effect is real but, before playing with magic, first invest your valuable time and money in the things that will guarantee high performance:
Optimise your training load.
Optimise your sleep, nutrition, and rest. No tricks. Just learn to understand yourself, watch for patterns, and intervene.
Full list of systematic reviews examining the placebo effect for recovery and performance.
Here is the list of systematic reviews I have summarised above.
Nonplacebo Controls to Determine the Magnitude of Ergogenic Interventions: A Systematic Review and Meta-analysis. Felipe Miguel Marticorena, Arthur Carvalho, Luana Farias DE Oliveira, Eimear Dolan, Bruno Gualano, Paul Swinton, Bryan Saunders. Med Sci Sports Exerc (2021)
The Placebo and Nocebo effect on sports performance: A systematic review. Philip Hurst, Lieke Schipof-Godart, Attila Szabo, John Raglin, Florentina Hettinga, Bart Roelands, Andrew Lane, Abby Foad, Damian Coleman, Chris Beedie. Eur J Sports Sci (2020)
Quantifying the placebo effect in psychological outcomes of exercise training: a meta-analysis of randomized trials. Jacob B Lindheimer, Patrick J O'Connor, Rod K Dishman. Sports Med (2015)
Nonplacebo Controls to Determine the Magnitude of Ergogenic Interventions: A Systematic Review and Meta-analysis. Felipe Miguel Marticorena, Arthur Carvalho, Luana Farias DE Oliveira, Eimear Dolan, Bruno Gualano, Paul Swinton, Bryan Saunders. Med Sci Sports Exerc (2021)
The Placebo and Nocebo effect on sports performance: A systematic review. Philip Hurst, Lieke Schipof-Godart, Attila Szabo, John Raglin, Florentina Hettinga, Bart Roelands, Andrew Lane, Abby Foad, Damian Coleman, Chris Beedie. Eur J Sports Sci (2020)
Quantifying the placebo effect in psychological outcomes of exercise training: a meta-analysis of randomized trials. Jacob B Lindheimer, Patrick J O'Connor, Rod K Dishman. Sports Med (2015)
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
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Position statements are written by a panel of experts (typically more than 10) chosen by the issuing society to grade the quality of evidence on a particular topic. The statements are typically peer-reviewed by several folks and go through several revisions before being published. Unlike other published reviews or original investigations, a position statement represents the journal’s (and the society that owns the journal) opinion — it is their position statement. A good position statement will use evidence from high-quality, large-scale, randomised controlled trials and, ideally, systematic reviews and meta-analyses, and then discuss the evidence in the context of practice.
There are several sports supplement-related position statements from the American College of Sports Medicine (ACSM), the International Olympic Committee (IOC), and the International Society for Sports Nutrition (ISSN):
ACSM — Nutrition and Athletic Performance position statement. Travis Thomas, Kelly Erdman, & Louise Burke. Med Sci Sports Exerc (2016)
IOC — Consensus statement: dietary supplements and the high-performance athlete. Ron Maughan and colleagues. Br J SportsMed (2018)
ISSN — Exercise & sports nutrition position statement. Chad Kerksick and colleagues. J Int Soc Sports Nutr (2018). The ISSN have also published individual position statements on the use of caffeine, creatine, beta-alanine, and HMB (β-hydroxy β-methylbutyrate).
Nutrition and Athletic Performance position statement. Travis Thomas, Kelly Erdman, & Louise Burke. Med Sci Sports Exerc (2016)
IOC —
Consensus statement: dietary supplements and the high-performance athlete. Ron Maughan and colleagues. Br J SportsMed (2018)
ISSN —
Exercise & sports nutrition position statement. Chad Kerksick and colleagues. J Int Soc Sports Nutr (2018). The ISSN have also published individual position statements on the use of caffeine, creatine, beta-alanine, and HMB (β-hydroxy β-methylbutyrate).
Which supplements do the position statements say have a beneficial effect on performance?
ACSM says that creatine (for very short-duration high-intensity efforts), caffeine (to reduce perception of fatigue and maintain power for longer), sodium bicarbonate (for short-duration high-intensity efforts), beta-alanine (for short-duration high-intensity efforts), and nitrate (for medium-duration endurance performance) have a high level of evidence for a beneficial effect on performance.
ISSN says that HMB, creatine monohydrate, essential amino acids (EAA), and protein have a high level of evidence for a beneficial effect on “muscle building” and that beta-alanine, caffeine, creatine monohydrate, sodium bicarbonate, and sodium phosphate have a high level of evidence for a beneficial effect on performance.
IOC says that creatine, caffeine, sodium bicarbonate, beta-alanine, and nitrate have a high level of evidence for a beneficial effect on performance (a veritable replica of ACSM’s guidelines). The IOC has also published a flow chart (see below) to help inform decisions about using sports supplements while reducing the risk of an anti-doping rule violation.
With that knowledge, always remember that taking a supplement does not make an athlete — a supplement does not replace training — there is no such thing as “exercise in a pill”. 
Strengthen the fight for Clean Sport.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body.
Ignorance is not an excuse!
Stay educated. Be informed.
Consult WADA’s prohibited list.
Cross-check your meds against the Global DRO drug reference list.
Only choose supplements that have been independently tested.
You are the only person responsible for what goes in your body. Ignorance is not an excuse! Stay educated. Be informed.
Thanks for using this tool. I am passionate about equality in access to free education. If you find value in my content, please help keep it alive by sharing it on social media and buying me a beer at buymeacoffee.com/thomas.solomon. For more knowledge, join me @thomaspjsolomon on Twitter, follow @veohtu on Facebook and Instagram, subscribe to my free email updates at veothu.com/subscribe, and visit veohtu.com to check out my other Articles, Nerd Alerts, Free Training Tools, and my Train Smart Framework. To learn while you train, you can even listen to my articles by subscribing to the Veohtu podcast.
Disclaimer: I occasionally mention brands and products but it is important to know that I am not affiliated with, sponsored by, an ambassador for, or receiving advertisement royalties from any brands. I have conducted biomedical research for which I have received research money from publicly-funded national research councils and medical charities, and also from private companies, including Novo Nordisk Foundation, AstraZeneca, Amylin, A.P. Møller Foundation, and Augustinus Foundation. I’ve also consulted for Boost Treadmills and Gu Energy on their research and innovation grant applications and I’ve provided research and science writing services for Driftline and Examine — some of my articles contain links to information provided by Examine but I do not receive any royalties or bonuses from those links. These companies had no control over the research design, data analysis, or publication outcomes of my work. Any recommendations I make are, and always will be, based on my own views and opinions shaped by the evidence available. My recommendations have never and will never be influenced by affiliations, sponsorships, advertisement royalties, etc. The information I provide is not medical advice. Before making any changes to your habits of daily living based on any information I provide, always ensure it is safe for you to do so and consult your doctor if you are unsure.
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About the author:
I am Thomas Solomon and I'm passionate about relaying accurate and clear scientific information to the masses to help folks meet their fitness and performance goals. I hold a BSc in Biochemistry and a PhD in Exercise Science and am an ACSM-certified Exercise Physiologist and Personal Trainer, a VDOT-certified Distance running coach, and a Registered Nutritionist. Since 2002, I have conducted biomedical research in exercise and nutrition and have taught and led university courses in exercise physiology, nutrition, biochemistry, and molecular medicine. My work is published in over 80 peer-reviewed medical journal publications and I have delivered more than 50 conference presentations & invited talks at universities and medical societies. I have coached and provided training plans for truck-loads of athletes, have competed at a high level in running, cycling, and obstacle course racing, and continue to run, ride, ski, hike, lift, and climb as much as my ageing body will allow. To stay on top of scientific developments, I consult for scientists, participate in journal clubs, peer-review papers for medical journals, and I invest every Friday in reading what new delights have spawned onto PubMed. In my spare time, I hunt for phenomenal mountain views to capture through the lens, boulder problems to solve, and for new craft beers to drink with the goal of sending my gustatory system into a hullabaloo.
Copyright © Thomas Solomon. All rights reserved.
I am Thomas Solomon and I'm passionate about relaying accurate and clear scientific information to the masses to help folks meet their fitness and performance goals. I hold a BSc in Biochemistry and a PhD in Exercise Science and am an ACSM-certified Exercise Physiologist and Personal Trainer, a VDOT-certified Distance running coach, and a Registered Nutritionist. Since 2002, I have conducted biomedical research in exercise and nutrition and have taught and led university courses in exercise physiology, nutrition, biochemistry, and molecular medicine. My work is published in over 80 peer-reviewed medical journal publications and I have delivered more than 50 conference presentations & invited talks at universities and medical societies. I have coached and provided training plans for truck-loads of athletes, have competed at a high level in running, cycling, and obstacle course racing, and continue to run, ride, ski, hike, lift, and climb as much as my ageing body will allow. To stay on top of scientific developments, I consult for scientists, participate in journal clubs, peer-review papers for medical journals, and I invest every Friday in reading what new delights have spawned onto PubMed. In my spare time, I hunt for phenomenal mountain views to capture through the lens, boulder problems to solve, and for new craft beers to drink with the goal of sending my gustatory system into a hullabaloo.
Copyright © Thomas Solomon. All rights reserved.