It's common knowledge that, as long as you avoid drones on your daily route, going for a run is good for you. Running is great exercise, it boosts your immune system, and it even puts you in a better mood. The mood-boosting benefits of running used to be credited to endorphins, but a team of German scientists discovered that runner's high is actually thanks to another set of chemicals in your brain—endocannabinoids—that are much closer to the chemicals released by smoking weed, The Daily Beast reports.
To test this, scientists, led by Dr. Johannes Fuss, conducted a study at the University of Heidelberg in Mannheim using mice and running wheels. Their resulting paper suggests that endocannabinoids, not endorphins, are responsible for the emotional boost and resistance to pain that comes from running. Endorphins are also produced while running, but, "one brain region produces endorphins for the brain, and another produces them for the body. Endorphins actually can’t pass through the blood-brain barrier." Endocannabinoids can pass directly from blood to brain, which more accurately represents what you feel when you're running.
To test their theory, scientists, placed exercise wheels into cages of mice.
To get a baseline effect of exercise on mouse physiology, Fuss and his colleagues habituated a population of mice to running on wheels, and separated them into two groups. One group was allowed to run before a series of behavioral experiments, and the other was not. Their anxiety and pain sensitivity were measured, demonstrating that when mice were allowed to run they experienced less of each. Expectedly, endocannabinoids were shown to increase in the running mice.
To prove their results, scientists gave mice either drugs blocking ednorphins or drugs blocking endocannabinoids. Mice that had endocannabinoids blocked didn't benefit from running anymore: They were no longer less anxious or less sensitive to pain. So next time you want to get high, take advantage of your body's natural cannibas and go for a run.