Published Feb. 4, 2022 in health.usnews.com
By Vernon Williams

Exercise increases concentrations of certain brain chemicals that contribute to an individual’s sense of well-being, memory enhancement and reward sensations.

Exercise has long been known and frequently touted as beneficial to your waistline and your heart health. Yet, in more recent years, the benefits of exercise on the brain and mental health have become a more mainstream topic of conversation.

Still, many people may not understand why those brain benefits of physical activity are so remarkable and profound. The neurological science behind the scenes of this phenomenon is technical and fascinating. But you don’t need to be a neurologist to understand the how and why of exercise’s effects on your brain.

Effects of Exercise on Your Brain

To begin explaining the positive effects of exercise on your brain, a simple understanding of something called brain-derived neurotrophic factor, or BDNF, is helpful. Without getting too technical, BDNF is a substance found in the brain that helps keep your brain cells healthy while encouraging new brain cell growth and facilitating communication between cells.

Some have likened BDNF to fertilizer for the brain. High levels of BDNF in the brain aid in neuroplasticity, helping our brains grow, change and adapt more nimbly in response to the world around us. Low BDNF levels, on the other hand, are associated with depression, anxiety, memory problems and brain degeneration over time.

So, if BDNF is such a good thing for the brain, how can we produce more of it? As it turns out, BDNF is created when the brain is stimulated. Many historical studies focused on brain stimulation with “brain game” activities like word problems and crossword puzzles. While these activities are suitable, newer and compelling research suggests that physical activity, especially aerobic exercise, can be the ultimate BDNF brain booster.

Best Exercise for Your Brain

From a clinical research perspective, some preliminary comparisons between moderate-intensity continuous training, or MICT, and high-intensity interval training, or HIIT, suggest increased BDNF in circulation after HIIT compared to MICT. However, there is still much work to be done to determine the best exercise mechanism, differences between fit individuals versus individuals with obesity or overweight, and what metric is used to determine a HIIT target.

When it comes to HIIT workouts, the brain experiences many short- and long-term responses and effects. From a short-term perspective, some immediate benefits to HIIT workouts include improved mood and cognitive function that can last for several hours after the exercise has ended. Additionally, there are measurable differences in BDNF after just a single HIIT workout, but they are usually temporary and return to normal about an hour after exercise.

The brain’s “feel-good” chemicals – endorphins and endocannabinoids, are released after a 20 to 30-minute (endorphin) and several hours (endocannabinoid) HIIT workout, respectively.

Long-Term Effects of Exercise on Your Mental Health

The long-term effects of exercise on the brain and mental health are also incredible. In general terms, exercise increases concentrations of dopamine, serotonin and norepinephrine, all of which contribute to an individual’s sense of well-being, memory enhancement and reward sensations.

Cardiovascular and aerobic (particularly HIIT) activity appears to be more effective than resistance or weight training for promoting an increase in circulating BDNF. Sustained elevations in BDNF are seen after as little as three months of regular aerobic and HIIT training. Regular exercise increases insulin receptor density and IGF-1, which helps insulin manage glucose levels in the body.

There continues to be growing and evolving studies and literature regarding the positive effects of exercise on a person’s stress response, particularly the “toxic stress response” often associated with adverse childhood experiences.

Exercise also increases the volume of some brain regions (six to 12 months), with positive effects on cortical re-organization, neuroplasticity and neurogenesis. Additionally, a regular aerobic exercise routine is shown to aid the prevention or reduction in the degree of age-related deterioration in grey and white matter cellular function.

Of course, with all of these brain benefits, there are also long-term reductions in cardiovascular risk factors associated with the dangers of cognitive impairment and dementia.

The positive effects of exercise on the brain cannot be overstated. When we consider all the tools at our disposal today to battle what continues to be a growing mental health crisis in our country, physical activity is generally free and easily accessible. As people in our society become more aware that the health benefits of exercise are real, I believe we may begin to turn a tighter corner on elevating brain health across the lifespan.