A systematic review of 18 publications found cannabis before exercise reduces work capacity, increases heart rate and oxygen demand, and impairs balance, concluding it is ergolytic rather than performance-enhancing.
Athletes, coaches, sports medicine professionals, anti-doping organizations
Cannabis is ergolytic: it impairs rather than enhances exercise performance
What the researchers found
Cannabis before exercise produces decrements in performance (reduced ability to maintain effort, lower physical/maximal work capacity), undesired physiological responses (increased heart rate, breathing rate, and myocardial oxygen demand), and neurological effects including impaired balance (increased sway).
Why it matters
Despite popular beliefs about cannabis enhancing sports performance, this comprehensive review provides clear evidence that cannabis impairs rather than enhances exercise performance.
The numbers in context
8 original studies; 10 literature reviews; cannabis causes reduced work capacity, increased heart/breathing rate, increased myocardial oxygen demand, and impaired balance; research uses ~6% THC but modern products reach ~150 mg THC
How the study worked
Systematic and umbrella review following PRISMA guidelines, searching PubMed, Scopus, and SPORTDiscus. Identified 8 original articles and 10 literature reviews. Evidence quality assessed using modified Downs and Black Checklist.
What this study cannot tell us
Most studies used low-potency cannabis (~6% THC) not reflecting modern products. Limited study designs. Research has not mimicked modern dosages (150+ mg THC). Few studies in trained athletes.
How to read the evidence
Systematic and umbrella review with consistent findings across multiple studies
When this study was published
Published in 2021. Studies used lower THC potency than modern products, meaning real-world effects may be greater.
The bigger picture
The conclusion that cannabis is ergolytic (performance-reducing) is important for sports anti-doping policy, as it challenges the justification for banning cannabis as a performance-enhancing substance.
Questions still open
- Would higher-potency products produce even greater performance decrements? Does CBD alone have different effects on exercise performance? Should cannabis be banned in sports if it impairs rather than enhances performance?
Common questions
Does cannabis enhance sports performance?
How does cannabis affect the body during exercise?
Read the original research
Acute effects of cannabis consumption on exercise performance: a systematic and umbrella review.
The Journal of sports medicine and physical fitness, 61(4), 551-561
Citation
Charron, Jérémie; Carey, Vincent; Marcotte L'heureux, Viviane; Roy, Philippe; Comtois, Alain S; Ferland, Pierre-Marc. (2021). Acute effects of cannabis consumption on exercise performance: a systematic and umbrella review.. The Journal of sports medicine and physical fitness, 61(4), 551-561. https://doi.org/10.23736/S0022-4707.20.11003-X
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