Smoking Weed Makes Exercise Fun, but Probably Hurts Performance

Smoking weed before a workout makes exercise more fun, but it probably isn't helping your performance, according to a new study from the University of Colorado Boulder.

Researchers began recruiting individuals over two years ago for the observational study, with participants running on treadmills multiple times with and without a pre-workout puff. After publishing the findings on December 26, the study's lead author announced that it's "pretty clear" that cannabis is not a performance-enhancing drug.

Although eating or ingesting cannabis in low doses is viewed as a performance enhancer by some long-distance runners and many athletic commissions list cannabis as a banned performance-enhancing drug, CU researchers believe that smoking weed before physical exertion won't help you run faster or longer. According to the study, published in Sports Journal, participants reported "more exertion" during runs after smoking pot, compared to running without smoking.

Lead author and CU professor Angela Bryan and Laurel Gibson, the study's principal analyst, worked with 42 different runners who said they already used cannabis before working out. Participants would run on a treadmill for thirty minutes without smoking, answer questions and then go home.

Days later, the runners would purchase one standard strain of high-THC cannabis or one strain of high-CBD cannabis (which has less intoxicating effects than THC) from a local dispensary. After smoking, runners would be picked up from home by CU researchers, who drove them to the lab for the same tests.

Across the board, runners reported more enjoyment and stronger euphoria during their post-smoking sessions, study results show, but THC smokers reported even more exertion than CBD smokers. According to Bryan, this could be because THC increases heart rates. The CBD group also collectively reported more heightened moods than the THC group, researchers note.

Although performance decreased slightly and more exertion was needed, Bryan and Gibson were just as interested in the desire to participate in exercise. According to Gibson, most lab research into marijuana's impact on exercise was conducted in the ’70s and ’80s using cannabis grown by the federal government, which is notorious for having nowhere near the THC potency (and zero CBD) of today's commercial pot products.

If people limit their pot smoking, Bryan sees a benefit to the increased enjoyment the plant brings, though she stresses that cannabis use can cause dizziness and loss of balance, neither of which you'd want to experience while on a treadmill. If it will get your ass off the couch, though, maybe it's not entirely bad, she says.

“We have an epidemic of sedentary lifestyle in this country, and we need new tools to try to get people to move their bodies in ways that are enjoyable,” Bryan says in an announcement of the study's results. “If cannabis is one of those tools, we need to explore it, keeping in mind both the harms and the benefits.”

Bryan also acknowledges that ingesting cannabis could have a different effect on physical performance, adding that it is "too early to make broad recommendations, but it’s worth exploring."