Supplements - creatine for runners, OCR athletes, and endurance training

How creatine affects performance and recovery for running, OCR, and endurance sports

Thomas Solomon, PhD.

Updated on December 14, 2025
Reading time approx 7 minutes (1400 words).

What you’ll learn:

Creatine is an amino acid–derived compound your body uses to help recycle cellular energy (ATP).

Taking creatine daily is very likely to boost maximal strength, reps-to-failure that last under about 3 minutes, and all-out speed efforts up to roughly 30 seconds.

Creatine is unlikely to improve endurance performance like time trials or time-to-exhaustion runs.

There’s early evidence suggesting that creatine might help short-term memory and reasoning, but we need more studies.

Curious about the how and why? Scroll down for the details, the nuances, and the nerdy bits.

The information I provide is not medical advice. Creatine can have side effects and might interact with other drugs, nutrients, and medical conditions (see here). If you are unsure, always consult your doctor to ensure that a specific supplement is safe for you to use.

What is creatine?

Creatine is a naturally occurring compound your body makes from the amino acids arginine and glycine. It isn’t built into proteins and it isn’t coded by your genes. Instead, creatine helps your cells manage energy, and about 95% of it lives in your muscles.

Your body makes some creatine from the amino acids, arginine and glycine, but also breaks it down to creatinine, which you pee out. That means you also need creatine from food to keep levels topped up. Eating meat (inc. red meat, chicken, pork, etc.), fish (e.g., salmon), and seafood can provide it. If you don’t eat those foods, supplements can fill the gap because creatine in supplements is chemically synthesised and not extracted from meat (and, strict plant-based folks can simply choose a plant-based capsule).

Creatine for runners, OCR, and endurance athletes from Thomas Solomon — The enzyme creatine kinase catalyses the reversible reaction between creatine (Cr) and phosphocreatine (PCr). When PCr is hydrolysed to Cr, a phosphate group is released, which is added to ADP to produce a molecule of ATP.

During exercise, your muscles chew through adenosine triphosphate (ATP), which is the cell’s “energy coin”. At very high power outputs, ATP from carbohydrate and fat isn’t made fast enough. That’s where phosphocreatine (PCr) comes in. Breaking down PCr into creatine (Cr) frees a phosphate molecule (Pi) that helps rebuild ATP quickly — basically a nitro button for brief, all-out efforts.

ATP hydrolysis: ATP → ADP + P_i + H⁺
ATP resynthesis: PCr → Cr + P_i then ADP + P_i → ATP

So if your muscles hold more creatine, you can produce more phosphocreatine and resupply ATP faster during maximal-effort, anaerobic or sprint-type work. Because daily creatine supplementation increases muscle creatine levels, creatine has become one of the most studied — and most popular — sports supplements. So…

What is the scientific evidence on creatine’s impact on athletic performance?

RightArrow 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.

RightArrow Creatine does not improve training-related gains in endurance performance (for example, time trials or time-to-exhaustion). In fact, one meta-analysisA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment. even reports small reductions in the training-induced improvements in V̇O₂maxV̇O₂max is the maximal rate of oxygen consumption your body can achieve during exercise. It is a measure of cardiorespiratory fitness and indicates the size of your engine, i.e., your maximal aerobic power, which contributes to endurance performance. (small effect sizeAn effect size is a quantitative measure of the magnitude of a relationship or difference between groups in a study. Unlike p-values, effect sizes show how large or meaningful that effect is. Common effect size measures include Cohen’s d, Hedges’ g, eta-squared, and correlation coefficients.).

RightArrow Creatine improves gains in maximal strength and in sets taken to failure that last under about 3 minutes (small to moderate effect sizes).

RightArrow Creatine improves high-intensity “anaerobic” performance, such as 30-second Wingate tests (large effect sizes).

RightArrow In older adults (60 and older), combining creatine with strength training helps preserve muscle mass (large effect sizes), muscle strength (small to moderate), and functional ability (for example, chair sit-to-stand; large) more than training alone — a handy add-on for healthy ageing.

RightArrow Early evidence suggests creatine might help short-term memory and reasoning in healthy people (Avgerinos et al. 2018). However, further randomised controlled trials are needed, especially in older populations, to make firm conclusions.

RightArrow Some studies note more stomach upset when caffeine and creatine are taken together, and chronic caffeine during a creatine loading phase might blunt creatine’s benefits (although the acute effect of caffeine seems intact). However, better trials are needed to fully map the caffeine-creatine interactions.

RightArrow Because meat contains creatine, people who avoid meat may have lower muscle creatine levels. Fortunately, creatine supplementation raises muscle creatine and improves high-intensity performance in plant-based eaters too. And again, the creatine in supplements is synthesised, not taken from meat; plant-based eaters might just want to ensure a capsulated creatine product uses a plant-based capsule.

RightArrow If you choose to use creatine, a reasonable dose that increases muscle levels of creatine is:

A loading phase of 5 grams of creatine monohydrate, 4 times per day for 5 to 7 days, then a maintenance dose of 3 to 5 grams per day. Note: These doses reliably raise muscle creatine and improve performance in studies.

Or skip loading and take 3 grams per day for 28 days. Note: This slower approach still raises muscle creatine, just later.

Taking more doesn’t necessarily mean a bigger effect, but some studies show that larger athletes may need to ingest up to 5 to 10 grams per day to maintain creatine stores.

When supplementation is stopped, muscle creatine levels usually return to baseline levels in around 4 to 6 weeks.

The verdict:

Can creatine enhance athletic performance?

Taking a daily creatine supplement alongside regular training is likely to improve performance during maximal strength and reps-to-failure tasks, and during high-intensity/maximal speed-based efforts lasting up to about 30 seconds.

The effect sizeAn effect size is a standardized measure of the magnitude of an effect of an intervention. Unlike p-values, effect sizes show how large the effect is and indicate how meaningful it might be. Common effect size measures include standardised mean difference (SMD), Cohen’s d, Hedges’ g, eta-squared, and correlation coefficients. is medium to large.

The effect appears to be similar between trained athletes and untrained folks.

The effect appears to be larger in males; however, this is probably due to a lack of widespread research in females rather than a lack of a biological effect. Further high-quality creatine research in females is needed!

Meanwhile, supplementation with creatine is unlikely to improve endurance performance — it may even blunt training-induced gains in V̇O₂max.

These conclusions are based on a moderate quality of evidenceA moderate quality of evidence means that, in general, studies in this field have some limitations. This could be due to somewhat inconsistent effects between studies, a moderate range of effect sizes between studies, and/or a moderate risk of bias (caused by a small to medium number of studies, small to medium numbers of participants, partially described randomization processes, some missing data, some inappropriate methods/statistics). When the quality of evidence is moderate, there is some doubt and only moderate confidence in the overall effect of an intervention, and future studies could change overall conclusions. The best way to improve the quality of evidence is for scientists to conduct large, well-controlled, high-quality randomized controlled trials.: there’s a large number of reasonably well-designed yet small studies and the effects are fairly consistent between studies (low to moderate heterogeneity/variability)Heterogeneity shows how much the results in different studies in a meta-analysis vary from each other. It is measured as the percentage of variation (the I² value). A rule of thumb: if I² is roughly 25%, that indicates low heterogeneity (good), 50% is moderate, and 75% indicates high heterogeneity (bad). High heterogeneity means there’s more variability in effects between studies and, therefore, a less precise overall effect estimate.. So, there’s a moderate level of confidence that the overall effect sizes reported in meta-analysesA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment. reflect the true effect of creatine.

To minimise the risk of consuming a supplement that contains prohibited substances, only choose products that have been independently tested (e.g., Informed Sport). And, remember: Supplements do not make athletes and do not replace training; they're just the icing on a very well-baked cake. Before reaching for pills and potions, optimise your training load and dial in your sleep, nutrition, and rest.

How to use this: If your goal is sprint speed, repeated surges, or strength, consider creatine monohydrate. Either load with 5 grams, 4 times per day for 5 to 7 days, then take 3 to 5 grams daily; or skip loading and take 3 grams daily for 28 days. Be consistent, watch how your gut feels if you also use caffeine, and if you stop, expect muscle creatine levels to drift back to baseline over about 4 to 6 weeks.

Strengthen the fight for clean sport

double right arrow Remember: 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, and only choose supplements that have been tested by an independent body (e.g., Informed Sport or LabDoor).

Information you can trust. All content on Veohtu is meticulously researched and written by Thomas Solomon, PhD. He does not sell supplements, recovery products, or ad space, and he has no sponsorships, brand affiliations, or ambassador roles. Everything you read reflects his independent views, shaped solely by peer-reviewed scientific evidence — and that will never change.

Full list of meta-analyses examining creatine for performance.

Here are the meta-analyses I've summarised above:

Share this article with your people:

This content is free.
Please help keep it alive by buying me a beer.

Who is Thomas Solomon?

My knowledge has been honed following 20+ years of running, cycling, hiking, cross-country skiing, lifting, and climbing, 15+ years of academic research at world-leading universities and hospitals, and 10+ years advising and coaching in athletic performance and lifestyle change.

I have a BSc in Biochemistry, a PhD in Exercise Science, and over 90 peer-reviewed publications in medical journals.

I'm also an ACSM-certified Exercise Physiologist (ACSM-EP), an ACSM-certified Personal Trainer (ACSM-CPT), a VDOT-certified Distance Running Coach, and a UKVRN Registered Nutritionist (RNutr).

Since 2002, I’ve conducted biomedical research in exercise and nutrition and have taught and led university courses in exercise physiology, nutrition, biochemistry, and molecular medicine.

And, with my personal experience of competing on the track (800m to 10,000m), the road (5 k to marathon), on the trails, and in the mountains, by foot, bicycle, cross-country ski, and during obstacle course races (OCR), I deeply understand what it's like to train and compete — I've been there, done it, and gotten sweat, mud, and tears on my t-shirt.

Subscribe to my newsletter

Join hundreds of athletes, coaches, scientists, and practitioners who receive my free summaries of the latest research in exercise and nutrition science. Empower yourself to train smart!

I will not bombard your inbox; I hate spam and respect your inbox as much as you do. Subscribing gets you first access to my latest articles and "nerd alerts" on cutting-edge exercise and nutrition science. It's all designed to help you train smarter. Give it a try and, if it’s not for you, unsubscribing is just one click away.

Disclaimer: I occasionally mention brands and products, but it is important to know that I don't sell recovery products, supplements, or ad space, and I'm not affiliated with / sponsored by / an ambassador for / receiving advertisement royalties from any brands. I have conducted biomedical research for which I’ve received research money from publicly-funded national research councils and medical charities, and also from private companies, including Novo Nordisk Foundation, AstraZeneca, Amylin, the A.P. Møller Foundation, and the Augustinus Foundation. I’ve also consulted for Boost Treadmills and Gu Energy on R&D grant applications, and I provide research and scientific writing services for Examine.com. Some of my articles contain links to information provided by Examine.com but I do not receive any royalties or bonuses from those links. Importantly, none of the companies described above have had any control over the research design, data analysis, or publication outcomes of my work. I research and write my content using state-of-the-art, consensus, peer reviewed, and published scientific evidence combined with my empirical evidence observed in practice and feedback from athletes. My advice is, and always will be, based on my own views and opinions shaped by the scientific evidence available. 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.