How CBD, THC, and cannabis affect performance and recovery for running, OCR, and endurance sports
Thomas Solomon, PhD.
Updated onReading time approx 7 minutes (1400 words).
What you’ll learn:
CBD (cannabidiol) and THC (tetrahydrocannabinol) are cannabinoids, which are chemicals found in cannabis plants.
THC and cannabis are very unlikely to improve strength or endurance performance and are more likely to impair it, especially if you take them before exercise.
CBD is also unlikely to improve performance or recovery. However, high-quality randomised controlled trialsThe “gold standard” approach for determining whether a treatment has a causal effect on an outcome of interest. In such a study, a sample of people representing the population of interest is randomised to receive the treatment or a no-treatment placebo (control), and the outcome of interest is measured before and after exposure to the treatment and control. are lacking, so the evidence is uncertain.
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. CBD and THC can have side effects and might interact with other drugs, nutrients, and medical conditions (see CBD here and THC & cannabis here). If you are unsure, always consult your doctor to ensure that a specific supplement is safe for you to use.
What are CBD, THC, and cannabis?
CBD (cannabidiol) and THC (tetrahydrocannabinol) are part of a family of chemicals called cannabinoids. THC is the main cannabinoid that causes the relaxing “high” you get from smoking, vaping, or eating marijuana, and it can also bring some less-fun effects like paranoia, sleepiness, short-term memory problems, dizziness, confusion, poor coordination, and slurred speech. People usually take THC by smoking or vaping cannabis or by eating “edibles” that contain THC.
CBD is extracted from dried, crushed cannabis plants but does not have the psychoactive “high” effect. Instead, it is heavily marketed as something that might help with pain, sleep, and inflammation, even though the hard performance data are kinda thin right now.
Cannabinoids have also been used to develop prescription drugs. For example, CBD is the active ingredient in Epidiolex, which doctors prescribe to treat seizures in people with some rare forms of epilepsy. THC is the active ingredient in Nabiximols/Sativex, which is used to help manage pain in people with multiple sclerosis. In some countries, doctors can also prescribe “medical marijuana”, and some folks use THC-containing edibles or smoke cannabis to help with anxiety or chronic pain.
However, even though these drugs exist, the overall effect and the risk/benefit balance of marijuana are still debated. Despite that, CBD and THC are now big business. Theoretical benefits of cannabinoids in sports are often mentioned in the sports science world, and papers regularly discuss potential roles for cannabinoids in athletes. Add a global wave of CBD oils, tinctures, and rubs promising greatness for athletes, and we land at the important question…
What is the scientific evidence on the impact of CBD, THC, and cannabis on athletic performance?
CBD and THC appear to be generally safe to consume for most people at typical doses, but some studies show that long-term, regular use of THC or smoking cannabis is linked with addiction and cognitive problems such as poorer memory and attention.
Inhaling smoke or vapor that contains solid particles and other chemicals is not exactly what your lungs are dreaming of. Smoking, whether it is cigarettes or cannabis, may impair lung function, which is not a smart goal for any endurance athlete.
At the time of writing, CBD is not on WADA’s prohibited list. However, WADA does ban the in-competition use of other cannabinoids, including THC. On top of that, many CBD products on the market are contaminated with THC, which means a “harmless” CBD oil could still trigger a positive doping test.
Effects of THC and cannabis:
So far, neither THC nor cannabis has been shown to improve exercise performance for strength or endurance. They also do not improve common lab markers of performance such as V̇O2max.
When people take THC or cannabis before exercise, breathing rate increases, balance gets worse, and strength and maximal work capacity go down. That is basically a checklist of things you don’t want on race day.
Some studies suggest that THC and cannabis can change mood and reduce pain. That might give certain sports or situations a small edge and probably explains why THC and cannabis are still on WADA’s in-competition prohibited list. But the side effects (sleepiness, short-term memory loss, dizziness, confusion, reduced coordination, and slurred speech) raise clear safety concerns in many sports. Add in the fact that cannabis is still an illegal drug in many countries, and you have several strong reasons why WADA continues to ban it.
Effects of CBD:
CBD is heavily marketed as a cure-all that seems to “fix” almost every system in the body. Right now, those claims are mostly anecdotal because evidence from a randomised controlled trialThe “gold standard” approach for determining whether a treatment has a causal effect on an outcome of interest. In such a study, a sample of people representing the population of interest is randomised to receive the treatment or a no-treatment placebo (control), and the outcome of interest is measured before and after the exposure to treatment/control. focused on performance or recovery in athletes does not yet exist to support the marketing story.
But an absence of evidence is not the same thing as evidence that CBD definitely does nothing. Right now, because there are so few clinical trials in athletes, there is not a meta-analysisA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment. that tests the effects of CBD on exercise performance or on recovery from training or racing (that will probably change as more research appears).
In the meantime, a 2020 narrative reviewA narrative review describes an entire body of evidence to summarise what is known on a topic. However, instead of using a systematic approach, a narrative review takes a subjective approach that allows the author(s) to express their opinion on the topic. by McCartney and colleagues dug into the existing science and concluded that “the available evidence is preliminary, at times inconsistent, and largely based on preclinical studies involving laboratory animals”. In other words, most of the work so far is not in real-world athletes.
A 2024 meta-analysisA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment. by Lo et al. found that taking CBD once (acutely) may slightly increase feelings of sedation compared with placebo but does not meaningfully change performance across a range of mental tasks. So, short-term CBD use on its own (without THC or other drugs) is unlikely to cause functional impairment. However, the longer-term effects of taking CBD every day on brain function have not yet been fully examined.
Another problem is the quality of over-the-counter CBD products. CBD is treated as a “dietary supplement”, which means that products are monitored, but not tightly regulated, and quality can vary a lot between brands. In one study that analysed the CBD content of 25 CBD oils, only 3 products contained an amount of CBD within 20% of what the label claimed, 15 products were far below the claimed amount, 3 contained THC above the legal limit, and 5 products did not report CBD content at all. For athletes who are drug tested, that is a big red flag.
Can CBD, THC, and cannabis enhance athletic performance?
For CBD, the main “evidence” for performance benefits still comes from stories and marketing, not from solid trials. The available research suggests that CBD is very unlikely to enhance performance. THC and cannabis are also highly unlikely to improve performance and, especially before exercise, cannabis is more likely to impair performance than provide any benefit.
Precise 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. estimates are unclear because there is no meta-analysisA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment. that combines data from multiple trials in athletes.
The effects are likely to be similar between trained athletes and untrained folks, and between males and females, but further comparative research is needed to be confident about this.
Keep in mind: even without a combined meta-analysis, existing systematic reviewsA systematic review answers a specific research question by systematically collating all known experimental evidence, which is collected according to pre-specified eligibility criteria. A systematic review helps inform decisions, guidelines, and policy. report high heterogeneityHeterogeneity 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. (variability) in study designs and effects between studies and a moderate-to-high risk of biasRisk of bias in a meta-analysis refers to the potential for systematic errors in the studies included in the analysis. Such errors can lead to misleading/invalid results, and unreliable conclusions. This can arise because of issues with the way participants are selected (randomisation), how data is collected and analysed, and how the results are reported.. This suggests that the overall certainty of evidenceCertainty of evidence tells us how confident we are that the results reflect the true effect. It’s based on factors like study design, risk of bias, consistency, directness, and precision. Low certainty means more doubt and less confidence, and that future studies could easily change the conclusions. High certainty means that the current evidence is so strong and consistent that future studies are unlikely to change conclusions. is lowA low quality of evidence means that, in general, studies in this field have several limitations. This could be due to inconsistency in effects between studies, a large range of effect sizes between studies, and/or a high risk of bias (caused by inappropriate controls, a small number of studies, small numbers of participants, poor/absent randomisation processes, missing data, inappropriate methods/statistics). When the quality of evidence is low, there is more doubt and less confidence in the overall effect of an intervention, and new studies could easily change overall conclusions. The most effective way to enhance the quality of evidence is for scientists to conduct large, well-controlled, high-quality randomised controlled trials.. Additional high-quality randomised controlled trialsThe “gold standard” approach for determining whether a treatment has a causal effect on an outcome of interest. In such a study, a sample of people representing the population of interest is randomised to receive the treatment or a no-treatment placebo (control), and the outcome of interest is measured before and after exposure to the treatment and control. are needed to conduct a meta-analysisA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment. and to increase the certainty (confidence) in the overall effect.
The nice part: CBD doesn't appear to hurt recovery or performance. So, if you like it and believe it works for you, give it a whirl. But, remember that time and money spent trying to improve your performance with something that has no obvious benefit might be better spent optimising your training load, sleep habits, and dietary/nutritional choices.
However, because cannabis is more likely to impair performance than be of any benefit, it would be wise to avoid THC or cannabis before exercise. Plus, because THC and cannabis are drugs, consult WADA’s prohibited list before use.
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 you are an endurance athlete, do not rely on CBD, THC, or cannabis to boost performance or recovery. Avoid THC and cannabis before and during training or racing, especially if you compete under WADA rules. If you choose to use CBD for general well-being, pick a third-party tested product, keep the dose sensible, and treat it as a small optional extra, not a shortcut that replaces consistent training, decent food, and a boringly regular bedtime.
Strengthen the fight for clean sport
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 CBD, THC, and cannabis for performance.
Here are the meta-analyses I've summarised above:
The Effect of Cannabidiol on Performance and Post-Load Recovery among Healthy and Physically Active Individuals: A Systematic Review. Bezuglov et al. (2024) Nutrients.
Does acute cannabidiol (CBD) use impair performance? A meta-analysis and comparison with placebo and delta-9-tetrahydrocannabinol (THC). Lo et al. (2024) Neuropsychopharmacology.
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).
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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.
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.