As this described by the NYT (maybe the original paper describes it better?), there's all sorts of problems with this conclusion: - A very small sample size -

As this described by the NYT (maybe the original paper describes it better?), there's all sorts of problems with this conclusion: - A very small sample size - Confounding factors: one group consists of collegiate runners (i.e., college students), and another consists of "young men" i.e., presumably men who didn't necessarily go to college. Even if both groups consisted entirely of college students, there might be other confounding factors that could explain the differences rather than running itself (eg: runners spend more time outside; runners' days are more structured; college runners probably drink fewer nights a week than average) - The control group "said that they had not exercised in the past year" - could it just be that exercise in some form improves brain functioning? I was a mediocre Division 3 cross country and track runner, so I feel like I'm qualified to say that while there are many benefits of running, improved brain function is not one of them.