Cannabis before exercise hurts performance: reduced endurance, increased heart rate, and impaired balance

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.

Charron, Jérémie et al.·The Journal of sports medicine and physical fitness·2021·Moderate EvidenceSystematic Review
RTHC-03056Systematic ReviewModerate Evidence2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Systematic Review
Evidence
Moderate Evidence
Sample
Not reported

What This Study 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).

Key Numbers

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 They Did This

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.

Why This Research Matters

Despite popular beliefs about cannabis enhancing sports performance, this comprehensive review provides clear evidence that cannabis impairs rather than enhances exercise performance.

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.

What This Study Doesn't 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.

Questions This Raises

  • ?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?

Trust & Context

Key Stat:
Cannabis is ergolytic: it impairs rather than enhances exercise performance
Evidence Grade:
Systematic and umbrella review with consistent findings across multiple studies
Study Age:
Published in 2021. Studies used lower THC potency than modern products, meaning real-world effects may be greater.
Original Title:
Acute effects of cannabis consumption on exercise performance: a systematic and umbrella review.
Published In:
The Journal of sports medicine and physical fitness, 61(4), 551-561 (2021)
Database ID:
RTHC-03056

Evidence Hierarchy

Meta-Analysis / Systematic ReviewCombines many studies into one answer
This study
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Analyzes all available research on a topic using a structured method.

What do these levels mean? →

Frequently Asked Questions

Does cannabis enhance sports performance?

No. This systematic review found cannabis before exercise consistently reduces performance by decreasing endurance, increasing heart rate and oxygen demand, and impairing balance. It is ergolytic, not ergogenic.

How does cannabis affect the body during exercise?

Cannabis increases heart rate and breathing rate during exercise while reducing the ability to maintain effort and maximal work capacity. It also impairs balance. These effects work against rather than for athletic performance.

Read More on RethinkTHC

Cite This Study

RTHC-03056·https://rethinkthc.com/research/RTHC-03056

APA

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

MLA

Charron, Jérémie, et al. "Acute effects of cannabis consumption on exercise performance: a systematic and umbrella review.." The Journal of sports medicine and physical fitness, 2021. https://doi.org/10.23736/S0022-4707.20.11003-X

RethinkTHC

RethinkTHC Research Database. "Acute effects of cannabis consumption on exercise performanc..." RTHC-03056. Retrieved from https://rethinkthc.com/research/charron-2021-acute-effects-of-cannabis

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.