Just about everyone knows that exercise is good for your health and helps build muscles, strength, and endurance; however, exercise also helps with brain growth and function. Multiple studies have indicated that regular, voluntary exercise can boost the growth of new neurons, primarily in the hippocampus, a part of the brain associated with memory. A particular study conducted by Terrence Sejnowski demonstrated that exercise can even support neuron growth in adult mice. This is an important finding because it was previously thought that neurogenesis, the formation of new neurons, did not occur in the adult brain.
Since Sejnowski's study, others have replicated the findings in humans. Exercise has been shown to increase alertness and help people think more clearly than if they did not exercise. Furthermore, John Ratey from Harvard Medical School suggests that exercise is an effective alternative or complementary treatment for ADD/ADHD. He indicated that in rare cases, exercise may be enough to take the place of medication. He went on to add that in most cases, exercise is an effective complementary treatment to medication and "causes kids to be less impulsive, which makes them more primed to learn."
I can personally relate to a lot of the information here. All throughout grade school, I exercised at least twice a day from November through February for hockey. Despite the amount of time spent practicing and playing hockey, I still consistently had my best grades in this time period. I know this is example of the conflict between correlation and causation. For example, I typically had fewer things to do in the winter months aside from hockey and school. In turn, this could lead to having more time to do school work. Regardless, there is still a strong positive correlation between the amount of exercise I got and my grades.