兔子先生传媒文化作品

In our new, bi-weekly series CUriosity, experts across the 兔子先生传媒文化作品 campus answer pressing questions about humans, our planet and the universe beyond.听

This week, Psychology and Neuroscience Professor Angela Bryan, answers: 鈥淲hat causes the runner鈥檚 high?鈥� (Hint: It may not be what you think.)

It can set in after just a few miles: Nagging aches grow numb, sense of time slips away, colors brighten and thoughts grow crisp. Afterward, runners say they feel less anxious, stronger and more confident鈥攅ven euphoric.

But what causes this legendary 鈥渞unner鈥檚 high?鈥�

For decades, scientists have suspected that endorphins and other 鈥渆ndogenous opioids鈥濃�攑ain killers made by our own bodies鈥攁re at play, coursing through our blood stream when we work out and attaching to the same receptors in the brain that drugs like morphine or oxycodone do.听

But, Bryan says, running may actually be more like smoking a joint than taking a pain pill.听

鈥淔or a long time, everybody thought that the runner鈥檚 high was caused by the activation of the endogenous opiate system, but we are now beginning to think it is actually the endogenous cannabinoid system instead,鈥� she explains.

She would know: The psychologist often starts the morning with a run, then heads into her lab where she studies how cannabis, a.k.a. weed, affects the human body.

Cannabinoids are essentially the active ingredients in cannabis. Some 鈥渆xogenous鈥� (from outside the body) cannabinoids, like THC (tetrahydrocannabinol), promote intoxication. Others, like CBD (cannabidiol) quell inflammation and anxiety. The human spinal column and brain are rich in cannabinoid receptors that these compounds attach to when someone eats a gummy or smokes cannabis flower.

But we also make our own.

Standing on the Boulder Creek path, her face glowing after a morning jog, Bryan explains:

鈥淚 feel amazing. It鈥檚 just this feeling of freedom and strength and confidence,鈥� she says as a pack of runners shuffles by. 鈥淓veryone we are seeing out here today is having that same experience, and I would be willing to bet that none of them used cannabis before their run today.鈥澨�

When we exert ourselves, our tissues release cannabinoids which slip perfectly into those same receptors, reducing pain and sparking euphoria.

As Bryan notes in , long-distance runners often describe running as a 鈥渄rug like鈥� experience (complete with difficulty assessing the passage of time). They also experience something akin to withdrawal when they can鈥檛 run.

Numerous studies have shown that high-intensity exercise (running more so than walking) leads to higher circulating levels of endocannabinoids in the blood.

Meanwhile, studies have begun to debunk the endorphin-runner鈥檚 high connection.

One found that when opioid receptors were chemically blocked with a drug called naltrexone, athletes still experienced the runner鈥檚 high. Another found that when cyclists had higher circulating levels of endorphins, they actually felt more, not less, stressed out.听

While it鈥檚 not necessary to use cannabis to get the runner鈥檚 high, many athletes, particularly ultra long-distance runners, do mix weed and workouts. They report that supplementing the cannabinoids their bodies make with ones from a dispensary can enhance the high or bring it on sooner.听

But there are downsides to that.

In one study of 42 runners published in the journal Sports Medicine, Bryan found that using THC or CBD during exercise did indeed boost motivation and make exercise more fun. But it also slowed folks down.

Her advice for those gunning for a fast 5k or a marathon PR: Stick with the high your own body gives you.