This I Believe

Physical activity essential to mental vigor.

[P]hysical activity may have helped to make early humans smarter.

“We think that what happened” in our early hunter-gatherer ancestors, he says, is that the more athletic and active survived and, as with the lab mice, passed along physiological characteristics that improved their endurance, including elevated levels of BDNF. Eventually, these early athletes had enough BDNF coursing through their bodies that some could migrate from the muscles to the brain, where it nudged the growth of brain tissue.

Those particular early humans then applied their growing ability to think and reason toward better tracking prey, becoming the best-fed and most successful from an evolutionary standpoint. Being in motion made them smarter, and being smarter now allowed them to move more efficiently.

And out of all of this came, eventually, an ability to understand higher math and invent iPads. But that was some time later.

The broad point of this new notion is that if physical activity helped to mold the structure of our brains, then it most likely remains essential to brain health today, says John D. Polk, an associate professor of anthropology at the University of Illinois at Urbana-Champaign, and co-author, with Dr. Raichlen, of the new article.

And there is scientific support for that idea. Recent studies have shown, he says, that “regular exercise, even walking,” leads to more robust mental abilities, “beginning in childhood and continuing into old age.”