Evolution At Work: Why Running Feels Great

Working out is good for you, but unlike so many other things that are good for you, it also has the bonus of feeling good, too. Commonly referred to as “runner’s high,” the high comes from chemicals produced by the body called endocannabinoids, which trigger pleasure centers in the brain – pleasure centers that are not unlike those activated by cannabis derivatives, hence the name.

Reward Yourself

The pleasurable reward is one of evolution’s ways of keeping us moving; humans could run longer distances escaped from predators, and could therefore breed; the extra benefit of the runner’s high increased those early humans’ ability to keep running. Today, that pleasure is all the more crucial considering how much more sedentary we’ve become as a species since the Industrial Revolution. 

Of course, we humans aren’t the only animals that run, but most of nature’s other notable runner aren’t bipeds like us. Do our four-legged friends also experience runner’s high? Did they make a different deal with evolution, beyond having four legs and no thumbs? A research team based out of the University of Arizona decided to find out, publishing their findings in The Journal of Experimental Biology.

The researchers recruited ten volunteers, all of whom already ran for pleasure on a regular basis. The researchers also gathered up some dogs, which are typically cursorial animals (or, in layperson’s terms, active mammals), as well as a group of ferrets, who are non-cursorial (non-active).

In The Lab

Blood samples were taken from the human and canine participants before and after running thirty minutes on a treadmill; the ferrets, along with being non-cursorial, were also uncooperative, so the researchers were only able to sample the ferret blood during after they were done on the treadmill and during rest. (Overall the ferrets wanted nothing to do with the research.)

Analyzing the blood, the researchers found that there had indeed been a sharp increase of endocanniboids, especially anandamide, in both the humans and the dogs. The ennocanniboid levels in the ferrets did not change at all, and it couldn’t be explained away by not having gotten blood samples right the ferrets ran. They simply did not experience the runner’s high.

They also discovered a correlation in the human volunteers between how good they said they felt and how much their individual ennocanniboid levels had increased; the better their post-running mood, the more anandamide was revealed to be in their systems.

Running: it’s good for you, and it provides, a good, free, natural high, which is definitely the best kind.  Go for a run today!