There are road races where you’re encouraged to run high, and gyms dedicated to working out stoned. But what actually happens if you smoke weed and then run—or jump, or lift?
“How marijuana affects your workout or performance depends largely on the type of exercise and goal at hand,” says Jordan Tishler, M.D., a Harvard-trained internist and leading cannabis therapeutics specialist.
And to be clear: There isn’t much hard scientific research on marijuana and exercise. One of the few studies we have, published recently in the Journal of Science and Medicine in Sport, reports that weed degrades peak performance. Researchers only looked at it qualitatively, so we don’t know how much of an effect smoking weed would have on your workout, Tishler points out. But for a race, competition, or even deadlift PR, you want to be at your best—so as best we know, skip the spliff.
That said, while smoking weed before your workout may diminish your peak performance, anecdotal evidence suggests smoking weed can heighten the enjoyment of certain activities, namely ones with repetitive motions, Tishler explains. “If you’re running on a treadmill, cannabis can make it more enjoyable—which can actually make you more motivated to run for longer, and to run more in the future.”
There are also a few risks to working out stoned. Cannabis can elevate your heart rate and drop your blood pressure, so for jacked dudes who already have higher adrenaline running around their bodies, working out high can up your chances of getting lightheaded. “It shouldn’t be too much of a problem, but it would be wise to be aware of this as an issue and not go for the biggest workout of your life the first time you try working out high,” Tishler adds.
Other times you should stay away: Anything that requires quick decision-making. “Cannabis can be good for focus and repetition, but it doesn’t necessarily enhance your critical judgment or timing,” Tishler says. For some people, getting high increases your chances of making risky decisions, which means you want to stay away from things like street cycling or rock climbing while high, according to older studies.
HIIT while high can be rough, too—studies show THC messes with your reaction time and your perception of short intervals (no one wants a set of mountain climbers to last any longer than it has to). Plus, the decreased sense of focus means you’re probably not staying on top of your form like you need to be.
Forgo the grass for game day or any high-reaction, high-risk workout where your safety relies on sharp judgment. When it comes to more low-key workouts—running, stationary cycling, weight lifting—whether it will help or hurt depends on what your biggest obstacle or goal is. “If you’re a serious gym rat, cannabis may degrade performance a bit, and that may be a deal-breaker. But if you’re more of a weekend warrior or trying to get into a new sport like running, cannabis can help you to overcome the discomfort of making the effort,” Tishler says.
Want to try it?
Assuming you live where marijuana is legal recreationally, Tishler recommends testing out sweating stoned with a short, low-risk workout where peak performance isn’t crucial—so not while attempting your deadlift max or on sprint training day, but maybe on a two-mile run.
And skip the edibles: It’s unpredictable how long they’ll take to kick in. Instead, Tishler says the healthiest way to ingest is to vaporize whole flower (some oils and cartridges contain chemicals from the extraction process).
Lastly, as any pothead could guess, strain matters. “My patients who are athletes are consuming high-end, specialized strains of cannabis that help them get focused and stay in the zone while exercising,” says Junella Chin, M.D., an integrative medical physician in New York and California specializing in medical cannabis and osteopathic neuromuscular medicine. “Then, my patients who are yogis are using a totally different strain to help with ligamentous strain, laxity and poses, relaxation, and getting them to meditate in a whole new level of awareness.”
Talk to the budtenders at your local dispensary about what you’re after—they’ll be able to direct you properly.