You know that exercise is good for your physical well-being. But did you know that working out may make you smarter, too?
“What affects our bodies affects our minds and what affects our minds also affects our bodies,” says J. Carson Smith, PhD, of the University of Maryland’s School of Public Health.
Researchers have started to examine how being physically active may counteract the effects aging can have on the brain. What they’ve found is that exercise influences the brain’s structural integrity, including the birth of new neurons, or nerve cells. Working out also has an impact on how much neuronal tissue is created and how that tissue functions, as well as how well blood circulates within the brain. All of these are factors in defending against the development of conditions such as Alzheimer’s disease.
One of exercise’s most profound effects is how it affects the ability of neurons to work together. Physical activity stimulates release of brain-derived neurotrophic factor, which Smith calls “a fertilizer for neural growth”; it helps make new connections between different regions of the brain and supports the growth of new neurons.
In studies of mice, aerobic exercise triggers the birth of nerve cells in the hippocampus, the part of the brain responsible for learning and memories, and where there’s a residual population of stem cells. In fact, exercise prods the hippocampus into producing double or triple the number of new neurons produced under sedentary conditions.
In terms of boosting brainpower, “it’s a very profound effect,” says Florida Atlantic University’s Henriette van Praag, PhD.
In studies of people, van Praag says, regular exercise has improved learning and memory. For example, researchers writing in the Journal of Alzheimer’s Disease found that older adults who had better cardiovascular fitness had healthier brains. That was true in people both with and without mild cognitive impairment, a stage between normal brain aging and true dementia. The brain’s white matter—the cables that transmit messages to different parts of the brain—showed fewer lesions and deterioration, highlighting exercise’s protective effect.
Research has found how exercise affects the brain’s prefrontal cortex, which is involved in planning, attention and decision-making. A 2018 study found that a half-hour of fast running improved cortical flicker frequency, which is linked to better cognitive function. Other studies have found that interval workouts ramped up connectivity and coordination in areas of the brain responsible for working memory and executive function.
Van Praag says that compared to stretching or light weight lifting—as valuable as those forms of exercise are for other reasons—it’s aerobic exercise like walking, running or cycling that has really been shown to stimulate cognitive health.
And you don’t have to work out intensely for hours in order to see these benefits. A recent JAMA study found that each additional hour of light activity netted the equivalent of 1.1 years less brain aging. Even a single half-hour exercise session improved brain function, specifically the ability to recall words, concepts and numbers. (Smith is now running a clinical trial for older adults with an increased genetic risk for Alzheimer’s to see if exercise can help delay onset.)
In addition, scientists are looking into the possible brain benefits of other forms of physical activity, like resistance training and yoga. A 2019 review of 32 previously published studies found that mind-body exercises like tai chi boost working memory, verbal fluency and other cognitive functions among older adults. In another study, regular yoga practitioners were found to have greater thickness in the left prefrontal cortex, which is definitely a good thing.
The bottom line: move your body. “By exercising the body, you also exercise the mind. Ultimately, that is going to increase quality of life and that’s the ultimate goal,” says Smith.