Um, we've known about running endorphines for decades? first result for google is eight years ago http://www.nytimes.com/2008/03/27/health/nutrition/27best.ht

Um, we've known about running endorphines for decades? first result for google is eight years ago http://www.nytimes.com/2008/03/27/health/nutrition/27best.html?_r=0 http://www.nytimes.com/2008/03/27/health/nutrition/27best.ht... scientific studies from 1996 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC474733/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC474733/