The Evolution of the Runners High
A study in the University of Arizona studies the natural high of long distance runners. Endocannabinoids are chemicals that alter and lighten moods just like marijuana, but this chemical is produced naturally by the human body. The humans who volunteered and various dogs ran for 30 minutes at 70% of their maximum heart rate. After running their blood was taken was taken and they both had significantly increased endocannabinoids after running. Neither species though had endocannabinoids after walking. So running creates a runner's high.
This article interested me because I always wanted to know why people ran so much.
Reynolds, G. (2012, April 25). The evolution of the runner's high. Retrieved from http://well.blogs.nytimes.com/2012/04/25/the-evolution-of-the-runners-high/