To the Point provides insights from AU faculty experts on timely questions covering current events, politics, business, culture, science, health, sports, and more. Each week we ask one professor just one critical question about what’s on our minds.

We all know that exercise is necessary for physical fitness. But we don’t always stop to consider exercise’s impact on brain health and fitness. 

But we should. Recent studies have shown that exercise improves our cognitive and mental health. In fact, exercise improves a vast array of brain functions: thinking, understanding, learning, and remembering, working memory, executive functioning, mood, and mental health. Exercise even offers protection against neurodegenerative disease including dementia.

How does exercise achieve all these things? How much exercise—and what types of exercise —do we need to improve our brain function? We asked Professor Evan Reister from AU’s Department of Health Studies to break it all down for us. 

Can you walk us through the ways that exercise affects our brain—and what we can all do to improve brain function?

Let’s imagine our brain as a garden. When we exercise, there are increases in proteins that help brain cells. One of the most well-studied of these proteins is brain-derived neurotrophic factor (BDNF). If we think of our brain cells as the flowers of the garden, BDNF acts as a fertilizer. It not only supports the health of the flowers, but also enables the flowers to produce seeds of their own. These seeds grow up to be new flowers, just as exercise promotes the growth of new brain cells (i.e., neurogenesis).

Exercise also helps your brain build more blood vessels (i.e., angiogenesis). This would be like building more irrigation pipes in a garden. These pipes help to ensure the plants get enough water, just as exercise ensures that your brain gets all the oxygen and nutrients it needs to work at its best.

Lastly, exercise creates connections between your brain cells (i.e., synaptogenesis). This would be like adding more paths in your garden. The paths make it easier for you to care for all the flowers. When your brain has more pathways between its cells, you can think faster and learn new things more easily. 

In the long term, these three mechanisms (neurogenesis, angiogenesis, and synaptogenesis) can change both the structure and function of the brain. Exercise is known to increase the volume of different parts of the brain involved in the formation of memory and learning. This would be like a section of your garden producing more flowers than usual. Additionally, exercise helps your brain become more adaptable and flexible, like how your garden can grow in different ways depending on how you tend to it.

In terms of improving brain function, any exercise is better than none. BDNF increases not only from long-term training, but also from a single workout. However, to experience the greatest benefits, consistency is key. For optimal BDNF levels, it is recommended to perform aerobic exercise of moderate to high intensity at least two to three times per week, with a duration of 40+ minutes per session. This includes activities such as hiking, running, bicycling, and brisk walking. While weight training exercises are recommended for various other reasons, the potential benefits they might hold for brain function are still unclear. 

About Evan Reister

Evan Reister is a professorial lecturer in AU’s Department of Health Studies. He studied Exercise Science and Neuroscience during his undergraduate years at Transylvania University in Lexington, KY, then completed a doctorate in Nutrition Science at Purdue University. While at Purdue University, Reister had a research focus on the effects of food properties and environmental factors on ingestive behavior and physiological responses in healthy adults. His studies included the examination of hummus as an afternoon snack, the assessment of package size and variety on snack intake, and an exploration of the mechanisms of action of a weight-loss device. Additionally, he had the great fortune of being a teaching assistant and graduate lecturer in various Nutrition Science and Food Science courses at Purdue University. Reister is passionate about teaching and encouraging student success both in his classroom and out in the world.