Think phys ed doesn’t help kids in the smarts department? Logging in hours playing video games or watching TV may be more fun than exercise, but jumping on a bike or hitting the tennis courts could do more to boost a teen boy’s brain than books alone.

Apparently, when it comes to measuring brain power and predicting future success in teenage boys, fitness counts.

Researchers at the University of Southern California and the University of Gothenburg in Sweden have discovered a link between fitness in eighteen-year-old boys and their cognitive capabilities.

In their study, the scientists looked at one-point-two million eighteen-year-old males, analyzing their scores on intelligence tests and their fitness levels. In every case, the more fit the man, the better he performed on the intelligence tests. The buffest eighteen-year-olds also proved to be more likely to attend college than their aerobically challenged peers.

The researchers found the same links among the nearly one quarter of study participants who were brothers, too. Why does this matter? This shows that the link between fitness and beefier brains exists regardless of genetics or factors like socioeconomic status.

So how can a teen get on the right path to reap some of these brain-building benefits? The experts say the time between fifteen and eighteen is crucial because the adolescent brain is still developing. According to the study, boys who upped their health status during these years performed better on intelligence tests than other boys.

And sometimes, a run in the park or a mean game of tennis is just as fun as a video game.