So Raichlen put regular runners through treadmill workouts of differing intensities. Before and after each run, he drew blood to measure endocannabinoid levels. Walking slowly for thirty minutes had no effect. Nor did the most intense workout, running at maximum effort. Jogging, however, tripled the runners’ levels of endocannabinoids. Moreover, the elevation in endocannabinoids correlated with the runners’ self-reported high. Raichlen’s hunch was correct. The runner’s high is a buzz.
