Runner’s high – the sensation many fitness buffs experience from the flood of pleasure-inducing brain chemicals that accompanies exercise – may have evolved as nature’s way of motivating the body to get needed physical activity, new research suggests.
A team of sports scientists, led by David Raichlen from the University of Arizona, studied a variety of mammals – dogs, ferrets and humans – and determined more active species (like us) experience runner’s high, but sedentary creatures do not.
“Aerobic activity has played a role in the evolution of lots of different systems in the human body, which may explain why aerobic exercise seems to be so good for us,” said Raichlen. “We got interested in the brain as a way to look at whether evolution generated exercise behaviors in humans through motivation pathways.”
Raichlen’s researcher, published in the Journal of Experimental Biology, noted athletes experience “runner's high” after exertion, which is caused by a rush of chemicals in the “pleasure centers” reward centers of the brain, which can produce feelings of pleasure and euphoria.
Raichlen and colleagues studied how how exercise influences the brain chemicals of two “active athlete” species (humans and dogs) and a low activity species (ferrets). They found dogs and humans experience the chemical changes, but the ferrets did not, suggesting the phenomenon evolved as a way to motivate humans (and dogs) to exercise in humans.
Researchers suggested their findings indicate exercise could be a cheap solution to many medical conditions, improving a person’s mental state as well as heart and lung health.