Stronger Muscles, Stronger Brains

A study conducted by Canadian  researchers showed that women who started a once-a-week strength-training program increased their mental ability by 15 percent compared with the twice-weekly balance-and-toning group. The major thing observed was that those who were doing the once-a-week strength-training program kept doing the program and it helped them. But the twice-weekly group did not continue it. The researches concluded: "while exercising more often may ideally be better for you, ultimately the best exercise program is one that you actually will keep doing."

http://www.aarp.org/health/fitness/info-01-2011/stronger_muscles_stronger_brains.html