What's good for the heart is also good for the brain.

It is known that aerobic exercise is good for the cardiovascular system. Exercise spurs the growth of new mitochondria in muscle cells and also creates greater density of mitochondrial cells in the brain. Studies show that a greater reservoir of mitochondria in brain cells could provide a buffer against neurodegenerative diseases such as Alzheimer's disease. Even light exercise such as walking promotes cognitive function and can increase the neuroplasticity of the brain. We humans have the capacity to have our brains change at all ages. Exercising will help to keep the brain flexible, dynamic, and changing throughout our lifetimes.