Aerobic Fitness And Your Brain

Get off your can and start running:

"There's also epidemiological evidence to back it up: for example, this massive Swedish study of 1.2 million men found that cardiovascular fitness at age 18 predicted cognitive performance and subsequent educational attainment. On the other hand, there was no correlation between muscular strength and cognitive performance. And it's not just a case of smart kids being more likely to to aerobic exercise; they also found that the amount of improvement in cardiovascular fitness between ages 15 and 18 predicted cognitive performance. In other words, it's not just that fit people are smart (correlation); it's also that getting fitter makes you smarter."

P.S. Or you can lift weights... ;)