Feel Good Effect of Running Similar to Marijuana use, study shows

A new study debunks previous findings that say endorphin causes runner’s high. The latest findings shows that endocannabinoids is the chemical responsible for the feel good effect among runners, suggesting that the experience is similar to the effect of marijuana on brain.

Endorphins are indeed produced when exercising but researchers said that it has smaller effect in the feeling of euphoria during prolonged running or other forms of aerobic, sustained exercise.

Researchers from the University of Heidelberg explained that endorphins can’t pass through the blood barrier going to the brain. However, endocannabinoids can travel directly from blood to brain.

“For decades, it was hypothesized that exercise-induced endorphin release is solely responsible for a runner’s high, but recent evidence has suggested that endocannabinoids also may play a role,” researchers wrote in the study.

In order to arrive at these results, senior author Dr. Johannes Fuss and his colleagues conducted three experiments to know the effect of endocannabinoids in runners.

First, they placed rats in a running wheel. The rat ran for about 10km/day over twelve hours each day.
“They’re really motivated to run; there are strong biological processes motivating these mice to run in running wheels, therefore they’re a good model to study why humans are motivated to do exercise,” Fuss said.

Authors of the study grouped the rats into two. In one group, rats ran in the wheel inside their cages, while others did not run. During each running routines, researchers determine the anxiety and pain level of rats.

In the rats that were permitted to run, they showed higher levels of endocannabinoids in their blood.

For the next phase, researchers tried to determine if endocannabinoids rather than the endorphins is causing the feeling of euphoria during running. To do this, they block the receptors of either endorphins or endocannabinoids in the rat while running. The rats, whose endocannabinoids were blocked, showed tiredness during the running routine.

In the last experiment, researchers developed rats that are genetically incapable of producing endocannabinoids in their brains. When these genetically altered rats put in running wheels, they ran normal at first, but after several days, they lost interest and became tired easily.

In conclusion, authors of the study said endocannabinoids is the chemical responsible for the feel good effect during long runs. The chemical is also an active ingredient in marijuana.