The Brain Chemistry Behind the Elusive Runner’s High

You Should Know: That floaty, sometimes even euphoric, feeling some runners get after a workout usually gets chalked up to the body releasing endorphins. However, the more likely cause is endocannabinoids, your body’s own version of compounds found in cannabis. Unlike endorphins, these molecules are small enough to cross the blood-brain barrier, and levels of one type of endocannabinoid, anandamide, rise post run and stay elevated for around 30 to 45 minutes after a workout.

Going Deeper: Differences in brain chemistry may help explain why some people get the feeling during most runs, while others rarely or never do. Surveys show that a majority of distance runners never experience it, and many feel drained or even nauseated at the end of a long run rather than blissful.

Takeaway: Research on anandamide is also still early, with the most significant study so far conducted in mice, so it’s not yet clear how closely it maps onto humans. But a true runner’s high is most likely during steady, moderate-to-hard efforts rather than fast sprints.

Bottom Line: Either way, running is great for your body, as well as your mood and mind. So if you’re up for doing it regularly, then treat any high as a bonus.