Great set of stories in Newsweek a few weeks back on exercise. One article in particular, Can Exercise Make You Smarter?, by Mary Carmichael (March 26, 2007) discusses the relationship between exercise and the brain.
Charles Hillman, of the University of Illinois' Neurocognitive Kinesiology Laboratory, has shown a correlation between physical fitness and performance on statewide standardized tests for 3rd & 5th graders in Illinois (see Castelli, D. M., Hillman, C. H., Buck, S. M., & Erwin, H. E. (in press). "Physical Fitness and Academic Achievement in 3rd and 5th Grade Students." Journal of Sport and Exercise Psychology.)
Carmichael asserts that Hillman's study isn't the only research to show this correlation: "... in a landmark paper, researchers announced that they had coaxed the human brain into growing new nerve cells, a process that for decades had been thought impossible, simply by putting subjects on a three-month aerobic-workout regimen." This sounds intriguing -- I'd like to read the research itself (ok, I'd just like to retrieve the article; I'm a librarian, not a researcher), so I wish Newsweek would cite their sources!
Hillman summarizes: "...exercise can affect cognition ... just as it affects muscles." The article describes in layman's terms how this might work, involving the chemical brain-derived neurotrophic factor (BDNF) -- which Harvard psychiatrist John Ratey calls "Miracle-Gro for the brain." He adds that a workout will help with "focus, calming down, impulsivity" as well.
And the effect seems to be relatively quick: after a 30-minute workout, Hillman notes that " 'within 48 minutes' your brain will be in better shape." Early results suggest that PE in schools could improve children's test scores: in Naperville, Illinois, "students with poor verbal skills have started taking PE immediately before reading class. Their report cards, says Ratey, are already looking better."
Exercise + education = smarter kids. Carmichael concludes that exercise isn’t enough: "kids have to hit the library as well as the gym."