The Chemistry of Runners High

Most interesting, there's an anandamide spike - to simplify, a pleasure chemical that is the endogenous compound for the receptor that THC stimulates. Chocolate has anandamide in it, which has been advanced as one reason for people's strange behavior around it. Include me on that list.

I originally found this at io9, which questions the evolutionary value of runner's high (or if it's just noise in an overtaxed system); one possible explanation is obvious in io9's link to a great Youtube video of an African persistence hunter. One of the reasons I started writing this blog was to puncture the Just-So stories of paleo enthusiasts who often claim that running is "unnatural" and bad for you. Yet here we have our species' remaining hunter-gatherers doing exactly that! (Apaches are reported to have done the same thing.)