For the study, they first designed a simple questionnaire that asked people some general questions about themselves, including their age, gender, height and weight. More specific questions delved into their relationships with marijuana and workouts.

The questionnaire probed how often people exercised or used cannabis and whether they combined the two, using the drug in some form within an hour before or four hours after a workout. It also asked if people felt that using marijuana made their workout more pleasurable, upped or reduced their desire to work out, and possibly hastened their recovery afterward.

Then the researchers sought out cannabis users in several of the states where the drug is legal, including Colorado, California, Washington and Oregon, recruiting participants through websites, dispensaries and clinics. They did not approach gyms or similar sites, because their interest was in how cannabis use affects exercise and not the other way around, Dr. Bryan says.

Eventually, they wound up with responses from more than 600 men and women who used cannabis, most of whom said they also exercised at least sometimes.

The researchers had expected that some, but probably not a majority, of these people would report swallowing, smoking or slathering on cannabis before or after exercise.

But they were wrong — and by a wide margin. It turned out that almost 82 percent of them said that they used cannabis around the time of their workouts.

This group tended to be younger, leaner and more often male than those who did not use marijuana in conjunction with exercise. They also exercised more often and imbibed or slathered on more cannabis.