Marijuana and Working Out: What the Science Actually Says
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Marijuana and Working Out: What the Science Actually Says

The information in this article is for educational purposes only and is not intended as medical advice. Cannabis laws vary by state and country. Always consult a licensed healthcare provider before combining any substance with exercise. BoxingInsider.com does not endorse or encourage the use of any illegal substance.

IMPORTANT NOTE FOR ACTIVE FIGHTERS: Marijuana (THC) is a banned substance in professional and amateur boxing under WADA, USADA, VADA, and virtually every state athletic commission. Fighters have had victories overturned, been suspended, fined, and stripped of rankings for testing positive. CBD was removed from the WADA Prohibited List in 2019, but CBD products frequently contain trace THC that can trigger a positive test. If you hold or are pursuing a boxing license, this article is not for you. This is written for recreational athletes and people who train for fitness — not active competitors.

The Lazy Stoner Myth Is Dead

For decades, the image of a marijuana user was someone melted into a couch eating Doritos. That image is outdated. A growing body of research — and a massive shift in how athletes actually behave — tells a very different story.

A University of Colorado Boulder study found that 80% of cannabis users in legal states use marijuana shortly before or after exercise. Not sitting around. Exercising. And among those who combined cannabis with workouts, 70% said it increased enjoyment, 78% said it improved recovery, and 52% said it boosted motivation.

Those numbers got the attention of researchers. The same team at CU Boulder, led by Professor Angela Bryan, conducted the first-ever laboratory study examining how legal, commercially available cannabis affects the experience of exercise. Published in the journal Sports Medicine in December 2023, the study put 42 runners on treadmills — once sober, once after using cannabis — and tracked everything.

The results challenged a lot of assumptions.

What the CU Boulder Study Found

The runners in the study — all experienced cannabis users who already incorporated it into their training — reported significant differences between their sober and cannabis runs:

  • 90.5% reported more enjoyment from exercise after using cannabis
  • 69% said it decreased their pain perception
  • 59.5% reported increased focus
  • 57.1% said it helped them stay motivated
  • 45.2% said it made time pass faster

Even more interesting: the euphoric “runner’s high” was more intense across the board when runners used cannabis beforehand. And the heightened mood was actually greater in the CBD group than the THC group — meaning athletes might be able to get mood benefits without the impairment that comes with getting high.

But here’s the critical counterpoint: cannabis did not improve performance. Runners in the THC group reported that the same intensity of running felt significantly harder. A previous study by the same team found that runners were about 31 seconds per mile slower after smoking. THC increases heart rate, which makes cardiovascular exercise feel more taxing even when the actual workload hasn’t changed.

As Professor Bryan put it plainly: “It is pretty clear from our research that cannabis is not a performance-enhancing drug.”

Why It Might Make Workouts More Enjoyable

The science behind cannabis and exercise enjoyment has an interesting connection: your body already has its own cannabis system.

The endocannabinoid system (ECS) is a network of receptors throughout your brain and body. Your body naturally produces compounds called endocannabinoids that bind to these receptors. For years, scientists believed that endorphins were responsible for the famous “runner’s high.” Newer research suggests that’s a myth — it’s actually endocannabinoids kicking in after sustained exercise that produce that feeling of euphoria and alertness.

When you consume cannabis — whether THC or CBD — those cannabinoids bind to the same receptors your body’s natural endocannabinoids use. The theory is that consuming cannabis before a workout may help athletes tap into that “runner’s high” faster, at lower exercise intensities, or amplify it during longer sessions.

This also helps explain why cannabis users report exercise feeling more enjoyable and less painful. The endocannabinoid system plays a role in pain modulation, mood regulation, and perception of effort. When those receptors are activated — whether by your body’s own chemicals or by plant-derived cannabinoids — the experience of exercise shifts.

That doesn’t mean cannabis makes you a better athlete. It means it might change how exercise feels. For someone who struggles to get off the couch, that distinction matters.

THC vs. CBD: Very Different Effects

Not all cannabis is the same, and the distinction between THC and CBD matters enormously for exercise.

THC (tetrahydrocannabinol) is the psychoactive compound. It gets you high. In the context of exercise:

  • Increases heart rate (which makes cardio feel harder)
  • Reduces reaction time and coordination
  • Alters perception of time and effort
  • May decrease pain perception
  • Increases enjoyment and mood
  • Impairs performance in speed, power, and precision tasks
  • Can cause dizziness, which is dangerous during intense exercise

A study published in the Journal of Applied Physiology found that cannabis containing THC reduced mean power output during a 20-minute cycling time trial, regardless of whether it was smoked or vaped. The performance hit is real.

CBD (cannabidiol) is non-psychoactive. It doesn’t get you high. For exercise:

  • No significant effect on heart rate
  • No impairment of coordination or reaction time
  • May reduce inflammation and support recovery
  • The CU Boulder runners in the CBD group reported more euphoria than the THC group
  • No measurable performance decrease
  • No dizziness or impairment risks

This is why CBD has gained traction in the fitness and recovery space — alongside other emerging modalities covered in our Biohacker Supplements Guide and Peptides Guide. In 2019, WADA removed CBD from its Prohibited List — it’s the only cannabinoid that’s permitted for athletes at all levels. But there’s a massive caveat we’ll cover in the competition section below.

For the average person training for fitness, not competition, CBD appears to offer potential mood and recovery benefits without the performance trade-offs of THC.

The Recovery Angle

Beyond the workout itself, a significant number of cannabis users report using it specifically for post-exercise recovery.

A 2023 survey published in the Journal of Cannabis Research examined 111 trained individuals who used cannabis (CBD and/or THC) alongside regular exercise. The findings showed that cannabis users commonly incorporated it into their recovery routines alongside conventional methods like stretching, foam rolling, and cold therapy.

The potential recovery mechanisms include:

A comprehensive review in Sports Medicine summarized that while investigations of whole cannabis and THC have generally shown either null or detrimental effects on exercise performance, studies of sufficient rigor to make conclusive claims are still lacking.

Anti-inflammatory effects. CBD in particular has demonstrated anti-inflammatory properties in preclinical research. Inflammation is the body’s response to exercise-induced muscle damage, and managing it is a key component of recovery. Whether CBD’s anti-inflammatory effects are significant enough to meaningfully impact exercise recovery in humans is still being studied, but the early data is promising.

Sleep quality. Many cannabis users report improved sleep, and sleep is the single most important recovery tool available. As we cover in our Sleep and Recovery Guide, growth hormone is released during deep sleep, tissue repair happens during sleep, and inadequate sleep derails recovery completely. If cannabis helps someone sleep better — and for many people it does — that alone could improve recovery outcomes.

Pain management. Cannabis’s effects on pain perception are well-documented. For someone dealing with the general soreness and discomfort that comes with hard training, using cannabis instead of NSAIDs (like ibuprofen) or opioids could be a safer alternative. For more on evidence-based supplementation that supports recovery, see our Boxing Supplements Guide. This is particularly relevant in combat sports, where chronic pain is essentially part of the job.

Appetite stimulation. The “munchies” are real, and for people who struggle to eat enough to fuel their training — particularly those in heavy training phases — appetite stimulation can actually be beneficial. Undereating is one of the most common training mistakes — as we cover in our Fighter’s Diet Guide — and if cannabis helps someone actually consume the calories they need for recovery, that’s not trivial.

The Risks — Don’t Ignore These

Research suggesting cannabis isn’t catastrophic for health doesn’t mean it’s risk-free. Honest assessment matters.

Cardiovascular effects. THC increases heart rate by 20-100% for up to three hours after use. For healthy individuals, this is generally manageable. For anyone with existing cardiovascular issues — heart disease, high blood pressure, arrhythmia — combining THC with intense exercise could be dangerous. Harvard Medical School researchers have noted that the cardiovascular risks are most concerning for people with existing heart conditions.

Coordination and injury risk. THC impairs coordination, reaction time, and balance. If you’re doing something that requires precision — heavy bag work, sparring, barbell lifts, jump rope, or anything where poor balance could mean injury — being impaired is objectively dangerous. Running on a treadmill at moderate intensity is one thing. Boxing training while high is a different risk profile entirely.

Respiratory concerns. Smoking anything — cannabis included — deposits particulate matter in your lungs. For someone training for cardiovascular fitness — whether that’s roadwork or boxing for weight loss — smoking is directly counterproductive. If you’re going to use cannabis with exercise, edibles, tinctures, or vaporizers avoid the combustion issue. Your lungs are a training tool. Treat them accordingly.

Dependency and habit formation. While cannabis is less physically addictive than alcohol, nicotine, or opioids, psychological dependency is real. If you reach a point where you can’t enjoy or motivate yourself to exercise without cannabis, that’s a problem, not a feature. The goal is for exercise itself to be the habit — cannabis should never become a prerequisite.

Cognitive effects. Long-term heavy cannabis use is associated with memory impairment and changes in brain structure, particularly in users who start young. These effects are more pronounced with high-THC products and chronic daily use. Occasional use appears to carry significantly less risk, but “occasional” and “daily” are very different things.

Quality and contamination. In states without robust testing requirements, cannabis products can contain pesticides, heavy metals, and molds. Edibles can have inconsistent dosing. This isn’t a cannabis-specific problem — it’s a regulation problem — but it’s worth knowing what you’re putting in your body, especially if health is the goal.

Where It’s Banned in Competition — And Why That Matters

Here’s where the conversation splits cleanly between “people who train for fitness” and “people who compete.”

WADA (World Anti-Doping Agency): Cannabis (specifically THC and synthetic cannabinoids) remains on the 2026 Prohibited List as an in-competition banned substance. The threshold is 150 ng/mL in urine. CBD was removed from the Prohibited List in 2019, but all other cannabinoids remain banned during competition. WADA reviewed cannabis in 2022 and concluded it belongs on the Prohibited List — not because it enhances performance (they acknowledge the evidence doesn’t support that), but because it violates the “spirit of sport” criteria.

Boxing commissions — it’s a patchwork: The landscape for boxing has shifted dramatically since 2021, but it’s not uniform:

  • Florida stopped testing fighters for cannabis entirely in 2021, following the recommendation of the Association of Boxing Commissions (ABC) medical advisory committee.
  • Nevada (NSAC) amended its policy in 2021 to no longer ban athletes for cannabis use, though fighters who show up visibly impaired can still be barred from competition.
  • California still uses the WADA threshold of 150 ng/mL, with a $100 fine for first offenses.
  • Other state commissions vary widely. Some still issue suspensions and overturn results. Others have quietly stopped caring.
  • The ABC medical advisory committee officially stated that “THC is not a performance enhancing drug, it is a performance suppressor and athletes who test positive for THC should not be punished in the same manner as an athlete that tests positive for performance enhancing drugs.”

For further reading on the boxing regulatory landscape, see the WBC Clean Boxing Program’s advisory on cannabis and alcohol and Boxing News Online’s in-depth feature on cannabis in boxing.

UFC/MMA: The UFC formally removed cannabis from its banned substances list effective December 31, 2023. USADA had already essentially stopped penalizing positive THC tests in 2021, requiring evidence of visible impairment on fight night to issue sanctions.

The CBD trap for tested athletes: CBD is technically permitted under WADA rules. But here’s the problem — most commercially available CBD products, including those labeled “THC-free,” can contain trace amounts of THC due to manufacturing processes, mislabeling, or cross-contamination. Full-spectrum CBD products intentionally contain small amounts of THC. Even broad-spectrum products aren’t guaranteed clean. Under WADA’s strict liability standard, the athlete is responsible for whatever is in their body, regardless of intent or product labeling.

If you’re a competitive fighter subject to drug testing: avoid all cannabis and CBD products during competition windows. Period. No exceptions. The risk is not worth it.

If you’re training for fitness with no competition testing: this section doesn’t apply to you.

Fighters Who’ve Been Caught

Cannabis has ended or disrupted more boxing careers than most people realize:

Philadelphia lightweight Avery Sparrow tested positive for cannabis after a second-round stoppage win in 2018. His victory was overturned to a no-contest, and he lost his boxing license for a year — at the peak of his momentum as a rising prospect. In boxing, where timing and career trajectory are everything, a year off for something that doesn’t enhance performance is a devastating setback.

The UFC’s history is even more instructive. Before the policy changes, fighters regularly had results overturned and received suspensions of up to nine months for testing positive. Nevada was particularly strict. The public backlash against these penalties — combined with track and field sprinter Sha’Carri Richardson’s high-profile Olympic suspension for a positive cannabis test in 2021 — accelerated the policy shifts across combat sports.

The trajectory is clearly moving toward decriminalization in sports. But “moving toward” isn’t “there yet.” If you’re a competitive fighter, the current rules are the current rules, regardless of where they’re heading.

The Practical Takeaway

Here’s the honest summary of where the science stands:

What cannabis appears to do: Increase exercise enjoyment. Improve mood during workouts. Reduce perceived pain. Potentially aid recovery through anti-inflammatory and sleep-promoting effects. Help some people exercise more consistently by lowering the motivation barrier.

What cannabis does not do: Improve performance. Make you faster, stronger, or more skilled. Replace proper training, nutrition, sleep, or recovery protocols.

The nuance that matters: The CU Boulder study specifically recruited runners who already used cannabis with exercise. Whether someone with no cannabis experience would have the same positive exercise response is unknown. Professor Bryan herself noted that it’s too early for broad recommendations.

If you’re going to use cannabis with exercise:

  1. CBD over THC for training. The mood benefits appear comparable or better, without the performance impairment, elevated heart rate, or coordination issues.
  2. Don’t smoke it. Edibles, tinctures, or vaporizers protect your lungs. If you’re training for cardiovascular fitness and smoking anything, you’re working against yourself.
  3. Don’t use it for activities requiring coordination. Moderate-intensity cardio on a treadmill or bike is different from boxing training, heavy lifting, or anything where impaired reaction time could mean injury.
  4. Start low. If you’re new to cannabis and exercise, use a low dose and do something familiar and low-risk. A 5mg edible before a walk is not the same as taking a huge rip before sparring.
  5. Don’t let it become a crutch. If you can’t train without it, that’s dependency, not optimization. The exercise itself should be the foundation.
  6. If you compete: stay away. Full stop. The policy landscape is changing, but changing isn’t changed. A positive test can erase a win, end a streak, or cost you a license.

Where This Fits in Your Training

Cannabis is not a supplement. It’s not a performance enhancer. It’s not a recovery modality on par with sleep, nutrition, or proper programming. What it might be — based on emerging research — is a tool that helps some people enjoy exercise more, train more consistently, and manage the discomfort that comes with hard training.

That’s not nothing. The biggest predictor of training results is consistency, and the biggest barrier to consistency is people not enjoying the process enough to keep showing up. Whether you’re getting back in shape after 40 or working through the mental health benefits of boxing, if cannabis helps someone bridge that gap, the data suggests there may be legitimate value there.

But context matters. A recreational lifter using CBD before a long run is operating in a completely different world than a professional fighter trying to make weight. Know which world you’re in, and make your decisions accordingly.

For more on building a complete approach to fitness without cutting corners, check out our 30-Day Boxing Fitness Comeback Guide and our full Recovery Modalities Guide.

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