According to a study by Betsy Hoza, a professor of psychological science at the University of Vermont, exercise releases hormones and brain chemicals that parallel the effects of commonly prescribed ADHD medications, but without the negative side effects which often accompany such meds.
Not only does exercise improve cognitive function, it even helps diminish anxiety and depression. Aerobic exercise in particular may help students with ADHD focus more and improve test scores in school. While exercising, children get a rush of hormones and brain chemicals -- Serotonin, Dopamine, and Norepinephrine -- that can trigger this improvement in mood and concentration.
However, it's important to remember that exercise only has a temporary effect, while the effects of medication can last for many hours. But even still, while it may not totally replace prescription drugs, the exercise has definite benefits that help children perform better academically and feel better about themselves.