Todd Zakrajsek, ITLC-Lilly Conference Director
Key Statement: Exercise changes brain chemistry and structure to facilitate better learning and memory.
Keywords: Exercise, Cognition, Wellness
According to the World Health Organization (2022), in the first year alone of the COVID-19 pandemic, reported cases of anxiety and depression surged by 25%. Mental health and self-care have never been more important, and our jobs have never been more challenging. One way to address many of these challenges is by increasing your heart rate through movement. Of course, always consult your health-care provider if you plan to start or increase an exercise routine.
How valuable is exercise? Mark Tarnopolsky, a genetic metabolic neurologist at McMaster University, said that “if there were a drug that could do for human health everything that exercise can, it would likely be the most valuable pharmaceutical ever developed” (Oaklander, 2016, para. 7). Benefits of regular exercise, according to the Centers for Disease Control and Prevention (CDC) include enhancing your mood; lowering your cholesterol; strengthening bones; and lowering the risk of some types of cancer, arthritis, and type 2 diabetes (CDC, 2021)! These same researchers say exercise will also help you sleep better, give you glowing skin, and spark your sex life. You just need to get into the habit of a regular exercise program.
Image of Todd Zakrajsek running on the beach with his grandson on a winter day.
Along with the benefits already noted, an additional benefit is that it will help you with those job-related cognitive tasks such as reading source material and grading papers. Multiple studies indicate that regular physical activity makes physiological changes in your brain that will help you learn faster and remember longer (Prina, 2014).
Impact of Exercising on the Brain
When you engage in activity that raises your heart rate, a host of things happen in your brain. Oxygen levels increase, blood flow increases, hormones are released, and even new connections between cells are stimulated. Increased heart rate also stimulates the production of brain-derived neurotrophic factor (BDNF). BDNF is critical in forming memories to be stored for long periods and provides the tools needed for synapses to collect information, process information, match it to an appropriate schema, and store it in a way that can be recalled later (Miranda et al., 2019). Increased levels of BDNF translate directly to better learning (Erickson et al., 2013).
Studies in the American Psychological Association (APA) show that brains of regular exercisers have more blood at rest than non-exercisers. Regular exercisers also have better memories related to people, places, and events in our lives. Finally, studies show that as people age, active people maintain higher levels of cognitive functioning than do sedentary people (APA, 2020).
Wendy Suzuki, a professor of neuroscience at New York University, researches the impact of exercise on mood, learning, memory, and cognition. Suzuki explains that as she started to exercise, her long-term memory got better, her attention got better, and her mood improved (TED, 2018). When you exercise regularly, you grow new brain cells and can even increase the size of the hippocampus (important brain structure critical to remembering). The prefrontal cortex (area important for critical thinking) also benefits from regular physical activity. Neurodegenerative diseases like Alzheimer’s attack these areas specifically, causing permanent damage. However, with regular exercise, the changes that happen in your brain can protect you from these and other incurable diseases. Although you can’t fix the damage to your brain once it happens, exercise will decrease the probability that the damage will occur in the first place (TED, 2018).
Timing of Exercise and Learning
Researchers have found that BDNF levels increase during a cognitive task only when the task is preceded by physical activity (Nilsson et al., 2020). There is value in exercising right before learning. Conversely, there is no—or at least, less—value in exercising immediately after learning. A team of researchers tested participants’ recall of images when they exercised immediately after seeing the images or after waiting 4 hours to exercise after seeing the images (van Dongen et al., 2016). Overall, research indicates it is best to exercise no more than 2 hours before learning or, if the exercise is after learning, it is best to wait about 4 hours after studying.
How Much Should You Exercise?
The U.S. Department of Health and Human Services (DHHS, 2018) recommends a target goal of 75 minutes of vigorous aerobic activity or 150 minutes of moderate aerobic activity each week, or some combination of the two. If you have not been exercising, you may not be able to do a 30-minute brisk walk right away. The CDC notes that just a bit over 22% of Americans are nearly totally inactive (no exercise other than their job for the past 30 days). It’s okay if you have to start slow—begin with 5 or 10 minutes of walking and work your way up. If that is your situation, you are certainly not alone.
Anything that raises your heart rate and keeps it in a training zone will work, whether that is a brisk walk; mowing your yard; or joining friends for a pickup game of basketball, volleyball, or soccer. For more information about appropriate target heart rates, see the CDC’s guide on target heart rates (CDC, 2020).
Walking has many positive outcomes, including increasing fitness and enhancing mood, creativity, and cognitive functioning while lowering risk of heart disease and type 2 diabetes (DHHS, 2018). Erickson et al. (2013) noted that walking at least 1 mile per day at an increased heart rate changes the brain and has also been associated with an increased hippocampus and prefrontal cortex size. In one study, all participants who walked outside could generate high-quality, creative answers to a test question, versus only half of those who remained seated inside. Those who walked indoors on a treadmill scored 60% higher on a test than those who remained seated (Wong, 2014).
As a faculty member, you are likely under a lot of stress and have a constant barrage of high-cognitive tasks, such as reading source material for your course and grading papers. Exercising has a plethora of health-related benefits to help you by facilitating the learning and recall of new information by changing your brain chemistry. Many people find it challenging to find time to exercise. Keep in mind that if exercise increases your mood and increases your cognitive processing, the time spent exercising pays for itself and delivers additional, fantastic life-changing benefits.
1. If you exercise regularly, what have you found to best motivate you to regularly engage
in an aerobic activity? If you do not exercise regularly, what is your primary reason for
not engaging in activity?
2. What information from this piece did you find most surprising? Did your preconceptions
change or was the information totally new?
3. Watch the 13-minute TED Talk by Dr. Suzuki at the following address:
https://www.youtube.com/watch?v=BHY0FxzoKZE. What did you find most interesting
or inspiring about the information she presented?
Note: Source material from this article was drawn from Chapter 11 of The New Science of Learning (3rd ed.) (Zakrajsek, 2022).
American Psychological Association. (2020, March 4). Working out boosts brain health.
Centers for Disease Control and Prevention. (2020). Target heart rate and estimated
Centers for Disease Control and Prevention. (2021). Benefits of physical activity.
Department of Health and Human Services. (2018). Physical activity guidelines for Americans
(2nd ed.). U.S. Department of Health and Human Services.
Erickson, K. I., Gildengers, A. G., & Butters, M. (2013). Physical activity and brain plasticity in
late adulthood. Dialogues in Clinical Neuroscience, 15(1), 99–108.
Miranda, M., Morici, J. F., Zanoni, M. B., & Bekinschtein, P. (2019). Brain-derived neurotrophic
factor: A key molecule for memory in the healthy and pathological brain. Frontiers in
Cellular Neuroscience, 13, 363. https://doi.org/10.3389/fncel.2019.00363
Nilsson, J., Ekblom Ö., Ekblom, M., Lebedev, A., Olga, T., Moberg, M., & Lövdén, M. (2020). Acute
increases in brain-derived neurotrophic factor in plasma following physical exercise
relates to subsequent learning in older adults. Scientific Reports, 10.
Oaklander, M. (2016, September 12). The new science of exercise. Time.
Prina, L. L. (2014). Physically fit students do better on academic test scores, says study
funded by a Kansas foundation. Health Affairs Forefront.
TED. (2018, March 21). Wendy Suzuki: The brain-changing benefits of exercise [Video].
van Dongen, E. V., Kersten, I. H. P., Wagner, I. C., Morris, R. G. M., & Fernández, G. (2016).
Physical exercise performed four hours after learning improves memory retention and
increases hippocampal pattern similarity during retrieval. Current Biology, 26, 1722–
Wong, M. (2014, April 24). Stanford study finds walking improves creativity. Stanford News.
World Health Organization. (2022, March 2). COVID-19 pandemic triggers 25% increase in
prevalence of anxiety and depression worldwide. https://www.who.int/news/item/02032022covid19pandemictriggers25increaseinprevalenceofanxietyanddepressionworldwide#:~:text=Wake%2Dup%20call%20to%20all,mental%20health%20services%20and%20support&text=In%20the%20first%20year%20of,Health%20Organization%20(WHO)%20today.
Zakrajsek, T. (2022). The new science of learning: How to learn in harmony with your brain (3rd