The study looked at about 640 people born in 1936. At age 70, the adults filled out questionnaires about their leisure and physical activity levels. Three years later they received MRIs of the brain.
Scientists discovered that those who got more physical exercise, such as walking several times a week, tended to have larger brains than those who didn't work out. The brain gets smaller as we age which experts say may play a role in memory loss. Those in the study who were physically active had less brain shrinkage.
People who were intellectually engaged and socially active did not see any protective brain changes, though there have been indications that these also carry benefits.
Earlier studies with seniors who took up either aerobic exercise or strength training also showed signs that the brain was getting benefits from the work outs.
Experts say these studies provide more evidence that losing our youth doesn't have to mean losing our brain power.