And the more you exercise, the better. Rigorous fitness training seems to improve some mental processes even more effectively than moderate activity. But anything is better than nothing. Men and women over age 65 who exercise just 15 to 30 minutes a week are far less likely to develop Alzheimer's disease even if they are genetically predisposed to it.
The research, which was a review of 40 years of studies on exercise and its effect on brain functioning in human and animal populations, concluded that exercising the body keeps the mind young. Why this happens is still unclear, but the link appears to be significant and sometimes substantial even though there have been varied opinions on the matter for years. Some studies show fitness training not only improves mental performance, but also can delay the onset of dementia.
Furthermore, there is evidence that exercise benefiting brain function can span several decades. For example, one study showed that people who participated in leisure-time physical activity twice a week during middle age had a reduced risk of dementia later in life. Exercise seems particularly beneficial to "executive control" functions, which include planning, scheduling, working memory and multitasking--all things that tend to decline significantly with age.
It gets better. Older people who are showing early signs of dementia can often put the brakes on mental decline by exercising. Even relatively short exercise interventions can begin to restore some of the losses in brain volume associated with aging.
Still, study leader Arthur F. Kramer says since most of the research is observational so a true cause-and-effect relationship cannot be established. The research findings were presented at the 114th Annual Convention of the American Psychological Association, August 2006.
--From the Editors at Netscape
