Having a runner’s was an evolutionary advantage for early humans and dogs, while ferrets never needed it. It is another reason to believe that we are born to run.
Last year, David Raichlen and his team published a study showing that dogs can experience a runner’s high, but ferrets cannot. They tested 10 humans, 8 dogs and 8 ferrets for endocannabinoids before and after a 30 minute run. Endocannabinoids are molecules associated with runner’s high. The animals were only positively encouraged and never forced. Sure enough, the researchers noticed that the endocannabinoid blood levels were increased after the runs in humans and dogs, but not in ferrets. In humans the raised levels correlated with feelings of well being.
Raichlen and his team concluded that developing a runner’s high must have been an advantage for early humans and dogs, as they had to run to hunt and scavenge for food. Ferrets on the other hand, sleep most of the day. They do not need to run long distances as they tend to hunt their prey in its own burrow or by ambushing it.
Endurance exercise often gives you feelings of well being, happiness, harmony, lack of pain… Together these feelings are called “runner’s high”, as you are more likely to experience them during long runs than during any other exercise. Not everybody experiences it, and nobody does so every time.
Scientists now think that it is mainly due to endocannabinoids, which are molecules that act on the brain and influence processes such as mood, pain sensation, appetite…Their chemical structure is similar to marihuana.
Our ancestors needed to run to get food, but it was an energy consuming and risky exercise. Scientists believe that having runner’s high was an advantage, as it stimulated them to take the risk and to have (hopefully) more and better food. Over the millions of years that we were hunters-gatherers, our bodies became perfectly adapted to exercise, and even started to need it on a regular basis to keep healthy. Getting a high was a reward for an essential activity. Unfortunately, the modern lifestyle with its sedentary behaviour has jeopardized everything.
In an interview with the editor of The Journal of Experimental Biology, David Raichlen says that runner’s high fails to make sedentary people physically active because you have to be fit enough to engage in endurance exercise before you can experience it. This explains why running is so hard when you are a beginner, but becomes addictive as you get fitter.