Truth: Plain old physical exercise seems to beat out any type of mental puzzle available, according to a wealth of recent research. Two new studies published this spring suggest that aerobic exercise — any activity that raises your heart rate and gets you moving and sweating for a sustained period of time — has a significant, overwhelmingly beneficial impact on the brain.

"Aerobic exercise is the key for your head, just as it is for your heart," wrote the authors of a recent Harvard Medical School blog post.