You Can Safely Ride Your Bike Under the Influence of Marijuana

January 12th 2016

A lot of marijuana users claim that smoking makes them feel closer to nature and more inclined to spend time outdoors. In particular, biking while under the influence of cannabis (or "stoned cycling") has proved popular — leading researchers to question whether the physical activity carries added safety risks while high. The answer turns out to be a resounding "no," a new study found.

RELATED: How Marijuana Affects Your Workout

In an effort to determine how pot affects a person's ability to ride a bike, researchers in Germany and Australia conducted an experiment. They had 14 test participants ride a bike through an obstacle course — first while sober, then after smoking one, two, and three joints — and compared their performance. The final results were published in the International Journal of Legal Medicine.

The test participants were all self-reported marijuana users, so THC, the main psychoactive component of cannabis, affected them differently than it would for non-users. The more frequently a person smokes, the higher their tolerance. Each joint contained 300 micrograms of THC per kilogram of body weight; they were cultivated by a Dutch grower, authorized for research purposes by the German government.

The participants were asked to inhale the joints for four seconds, hold their breath for 10 seconds, and exhale for 15 seconds. Then they were instructed to bike through an obstacle course, and for each mistake they made — veering off the track, knocking over barrels, running red lights, stalling at green lights, etc. — they received a demerit and points off their final score. As it turned out, it didn't seem to matter how much marijuana the stoned cyclists smoked.

Here's a diagram of the obstacle course.

mapInternational Journal of Legal Medicine -

"Hardly any coordinative disturbances could be detected under the influence of high or very high THC concentrations," the researchers wrote. "Only a few driving faults were observed even under the influence of very high THC concentrations… On average, there is no increase in the number of demerits after the cannabis consumption."

And while the experiment was not meant to be interpreted as evidence that driving under the influence of marijuana was safe (it is illegal to do so, and it is not recommended), the results do appear to confirm that regular marijuana users respond differently to THC than non-users. For infrequent users, high concentrations of THC would presumably affect basic motor skills and coordination; but as far as biking while high is concerned, "[h]ardly any coordinative disturbances could be detected" for frequent users.

What does science say about biking while drunk?

Meanwhile, a 2009 study of biking accidents in New York City revealed that one in five bicyclists who died within three hours after getting in an accident had alcohol in their system. The researchers cautioned, however, that it is not entirely clear that alcohol was a factor in their deaths.

RELATED: What Marijuana Does to Your Metabolism

"It’s a no-brainer to be sober when you ride in New York City,” Catherine Stayton, director of New York's Department of Health and Mental Hygiene, told The New York Times. "Being alert and conscious of everyone else on the road is the best protection a bicyclist has, and biking while impaired makes our already dangerous streets an even greater risk."

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