Why Does Exercise Build Brain Power?
The brain, like all muscles and organs, is made of tissue, and its function declines with underuse and age. Beginning in our late twenties, most of us will lose about one percent annually of the volume of the hippocampus, a key part of the brain related to memory and certain types of learning. Exercise seems to slow or reverse the brain’s physical decay, just as it does for muscles. A newly discovered fact contributes to this reversal.
Scientists used to believe that humans were built with a finite amount of brain cells and would never generate more, but they now know better. In the 1990s, using a technique that marks newborn cells, researchers determined during autopsies that adult brains contained quite a few new neurons. Fresh cells were especially prevalent in the hippocampus, indicating that the creation of new brain cells was occurring primarily there. Even more exciting : scientists found that exercise jumpstarts neurogenesis. In the Rhodes study, mice and rats that ran for a few weeks generally had about twice as many new neurons in their hippocampi than mice that were sedentary. “Their brains, like other muscles, were bulking up.”