What do we know about exercise and brain health?As of today we know: 1) adults 65 and older are the fastest growing demographic group, reaching 20% of the world population by 2030; and 2) maintaining a sharp mind is a top priority for them. The idea that a healthy mind lives in a healthy body dates back at least 2,000 years, and the benefits of exercise beyond physical health is not a new idea either. The New England Journal of Medicine said this in 1887:
What is the ideal exercise for brain health?The verdict is still out on an ideal exercise “dose” for brain health, because in short, it’s complicated. The long answer is that we are still learning about all the ways in which exercise changes our biology, since not all exercise is created equal, and of course it ultimately depends on who we are, for we are all different. The best exercise program for one person may be quite different from the best one for another. A wealth of studies both in humans and animals have linked the cognitive improvements following exercise (mainly aerobic, such as running and cycling) to the increased capacity of the heart, lungs, and blood to transport oxygen. As a result, generalized brain effects, such as a boost in the number of blood vessels and synapses, increasing brain volume, and decreasing age-related brain atrophy, have all been reported. Aside from this, more localized effects in brain areas related to thinking and problem solving have also been reported, such as a boost in the number of new nerve cells and increases in proteins that help these neurons survive and thrive.
On the other hand, in recent years cognitive improvements have also been demonstrated with other forms of exercise, such as low-intensity mind-body exercises (think some forms of yoga and tai chi) and resistance (i.e., weight) training. Because these exercises either do not work the heart as hard, or do so in a different way, we know less about exactly how they promote these cognitive changes. However, I see this as an encouraging finding for two reasons. First, some sedentary people may need to start with a more gentle routine, eventually building up to more vigorous exercise practices; and second, many people already engage in resistance training for other reasons, such as building stronger muscles and bones.