You know that friend who’s really, really into running? The one who does a dozen marathons a year and Instagrams the living hell out of each one? That person has a secret: She’s basically on drugs.
A new study published in the Proceedings of the National Academy of Sciences found that running boosts chemicals in your brain that mimic the effects of pot. German researchers sought to figure out what was really behind the “runner’s high,” the amazing feeling that long-distance runners say keeps them going, mile after mile.
The scientists tested the anxiety levels of mice and then gave them running wheels. Mice really love to run, unlike certain humans (read: me), and tended to run three miles a day on their wheels. They found that anxious mice who went for a run were much calmer after running, and that levels of endorphins and endocannabinoids in their bloodstreams were elevated. When scientists blocked the mice’s ability to use endorphins, they were still really blissed out, but when they blocked their ability to use endocannabinoids, they were anxious and had a low tolerance to pain.