It wasn't until recently that researchers turned their interest to children -- in whom exercise may have more impact. The brain's frontal lobe, thought to play a role in cognitive control, keeps growing throughout the school years, says Charles Hillman, associate professor of kinesiology and neuroscience at the University of Illinois. "Therefore, exercise could help ramp up the development of a child's brain," he says.
In a 2007 study published in the Journal of Sport & Exercise Psychology, Hillman put 259 Illinois third and fifth graders through standard physical education routines such as push-ups and a timed run, and he measured their body mass. Then he checked their physical results against their math and reading scores on the Illinois Standards Achievement Test. "There was a relationship to academic performance," says Hillman. "The more physical tests they passed, the better they scored on the achievement test." The effects appeared regardless of gender and socioeconomic differences, so it seems that no matter his or her race or family income, the fitness of a child's body and mind are tightly linked.
The bigger the dose of exercise, the more it can pay off in academic achievement. In a study published the same year in the Research Quarterly for Exercise and Sport, researchers found that children ages 7–11 who exercised for 40 minutes daily after school had greater academic improvement than same-aged kids who worked out for just 20 minutes.
Edutopia: A Fit Body Means a Fit Brain by Vanessa Richardson