Anecdotally it seems obvious that people who stay physically active face old age with greater resilience than their more sedentary peers. A new study, analyzing over a decade’s worth of data might be just the motivation to get couch potatoes moving.

Cyrus Raji from the University of Pittsburgh have shown that loss in brain volume (a symptom of old age)  is decreased in those who are more physically active. A cohort of 299 adults (mean age of 78 years) were analyzed over the course of 13 years. After correcting for various factors, the Pittsburgh group concluded that walking around 72 blocks on average over 2 weeks, about 5 miles per week was enough to spare loss of brain volume.

Waking at a medium pace on a treadmill (2-3 miles per hour) can let you cover this distance in a half-hour. Even better, the study concluded that walking more than this distance did not help spare any more brain volume.

The study’s authors hope that this brain saving exercise regimen could help slow the progress of Alzheimer’s which is characterized by loss in brain volume, amongst other symptoms.  With the limited number of treatments now available for Alzheimer’s, any treatment, especially one as simple as a walk in the park is a valuable addition to preventing this disabling condition.

These findings were presented at the 2010 meeting of the Radiological Society of North America.