ReviewPhysical activity and the brain: A review of this dynamic, bi-directional relationship

•The brain plays a major role in regulating activity and exercise performance.•Physical activity improves brain-related function and outcomes.•Emphasis is placed on the effects of physical activity on Parkinson's disease.•Implications for this bi-directional effect are discussed.

The brain plays a major role in regulating physical activity behavior and exercise performance. Regular physical activity may also play a key role in the prevention and treatment of various neurological conditions, such as Parkinson's disease, Alzheimer's disease, depression, and cognitive function. This implies that not only does the brain (or the nervous system) regulate aspects of physical activity, but also that physical activity may potentially influence brain-related function and outcomes. This review details this bi-directional relationship and addresses its implications for improving physical activity, exercise performance, and brain-related function and outcomes.