When you participate in aerobic activities - those that get your blood pumping and your body sweating - you know you're doing your heart good. But did you know you may also be benefiting your brain? According to a recent study, aerobic fitness may reduce the amount of brain tissue loss that older adults experience. The results are published in the Journal of Gerontology.

Cardiovascular fitness affects the brain

Researchers studied 55 adults between the ages of 55 and 79 (average age 66.5) to see if there was a link between aerobic fitness levels and brain tissue density. They measured the subjects' aerobic fitness levels by calculating their VO2 scores (a measure of the body's use of oxygen) and evaluated brain tissues using magnetic resonance imaging (MRI). In doing their statistical analyses, the researchers accounted for other factors that might influence brain health, including alcohol and caffeine consumption, use of hormone replacement therapy, years of education, and high blood pressure.

They found that cardiovascular fitness substantially reduced age-related declines in tissue density in certain areas of the brain, particularly in areas of the brain that play a role in everyday functioning. This finding may be especially significant, because older adults often lose their ability to perform many daily activities as a result of age-related mental decline.

How it works

There are a variety of ways in which aerobic exercise may influence the structure and function of the brain. The exact mechanism has yet to be identified, but it is likely to be a combination of several chemical and molecular processes that influence brain health and integrity.

It's important to keep in mind that this was a small study of only 55 people, all of whom were relatively healthy, high-functioning, and without existing neurological problems. Therefore, the results cannot necessarily be applied to other groups of people.

Still, the researchers say that this is the first evidence of the effects of aerobic fitness on declines in brain tissue and that future research in this area "seems both promising and highly desirable." They also say that because of the growing population of older adults and the costs associated with age-related mental decline, finding ways to possibly prevent this decline is an important public health goal.

"Working out" your brain

While research in this area continues, this study adds to hundreds of others that show that regular exercise is crucial for healthful aging. If you're looking to begin an exercise program, be sure to consult your physician first, and if you need some guidance, seek out the services of a local YMCA, senior center, community center, or outpatient hospital-based fitness program.