Most people hit the gym, bike path or track because of what it does for their bodies. But regular physical activity may have brain benefits as well.

Two studies recently presented at the Alzheimer's Assn.'s International Conference on Alzheimer's Disease in Vienna this week showed how exercise provides a boost to mental acuity. In one, researchers looked at physical activity and results from a cognition test in 3,075 men and women aged 50 to 79 who were part of the Health, Aging and Body Composition Study. Their levels of physical activity (determined by how many minutes they walked per week) and cognitive function were noted at the beginning of the study and at two, four and seven years. Those who didn't develop dementia and maintained or increased their levels of exercise had substantially lower rates of cognitive decline than those who were more sedentary, or saw their physical activity decline.

In another study, 90 women aged 60 to 63 were asked to report how much strenuous and moderate recreational activity they did from high school through menopause. The women were also given neuropsychological tests that measured memory and frontal lobe function.

Those who engaged in more moderate activity did better overall on brain function tests, and those who did more strenuous exercise throughout the years performed more poorly on the tests. Researchers noted that though long-term strenuous exercise has a protective effect for breast cancer, it could have harmful effects on cognition, although larger-scale studies are necessary to better understand the implications for recommending activity and lifestyle regimens.

-Jeannine Stein

Photo credit: Stephen Osman / Los Angeles Times