Exercise and the Brain

Do you really want to do well on the SATs?

Maybe instead of sitting in test prep classes, you should use those tedious hours to go for a run.

According to a number of studies cited by the New York Times (What Sort of Exercise Can Make You Smarter?), there is strong evidence that aerobic exercise stimulates the creation of new brain cells, enabling mice -- and people -- to perform better on all sorts of mental tests.

Light aerobic activity seems to help, but strenuous aerobic activity seems to help more, triggering a dramatic change in blood flow in the brain, which in turn helps create more neurons and connections. However, anaerobic exercises -- like weight training -- seem to have a major effect on muscles, but not so much on the brain.

"Why should exercise need to be aerobic to affect the brain? “It appears that various growth factors must be carried from the periphery of the body into the brain to start a molecular cascade there,” creating new neurons and brain connections, says Henriette van Praag, an investigator in the Laboratory of Neurosciences at the National Institute on Aging. For that to happen, “you need a fairly dramatic change in blood flow,” like the one that occurs when you run or cycle or swim. Weight lifting, on the other hand, stimulates the production of “growth factors in the muscles that stay in the muscles and aren’t transported to the brain,” van Praag says."