Dave Raichlen on the Science of Runner's High

Dave Raichlen studies the elusive beast known as runner’s high.  Not everyone who runs gets it, it seems to come and go for those who do, and science doesn’t yet know the magic spell that brings it on just yet.  But Dave Raichlen at the University of Arizona at Tucson is getting closer. He’s looking at runner’s high from a evolutionary perspective, by studying people, dogs and ferrets.