How Exercise Protects the Brain

A growing body of research shows that regular physical activity is one of the most effective strategies available for protecting the brain — and that the benefits extend to people who have already been diagnosed with cognitive decline.

How exercise changes the structure of the brain

When most people think about the benefits of exercise, they might picture stronger muscles or a healthier heart. But exercise also reshapes the brain.

Research shows that regular physical exercise can improve cognitive function by supporting key brain structures. Physically active individuals tend to have greater gray matter volume, which is important for memory, learning, and decision-making and may help reduce age-related cognitive decline. 

Exercise is also associated with stronger white matter integrity, which helps transfer signals between different parts of the brain and supports faster information processing and overall cognitive performance. Together with enhanced blood flow to the brain, these structural advantages may contribute to better memory, sharper thinking, and greater resilience against age-related decline.

Exercise also promotes the growth of new brain cells in the hippocampus, a key area for learning and memory. This process, known as neurogenesis, can help make the brain more resilient to cognitive decline.

A key mechanism behind these benefits is a protein called brain-derived neurotrophic factor, or BDNF. Exercise increases BDNF levels in the bloodstream,  supporting the survival of existing brain cells and promoting the growth of new neural connections.

Wendy Suzuki, a professor of neuroscience and psychology at New York University, explained that exercise allows people to reshape their brains. The hippocampus grows larger as new cells are born. The prefrontal cortex — the region that governs focus, decision-making, and attention — functions better. And the insulating material around nerve fibers improves, making communication between brain cells faster and more efficient.

“You can imagine the brain is kind of like a muscle; the more you exercise, the more growth factors you have, and the bigger your hippocampus is, because you have more cells,” Suzuki told Being Patient. “You are literally re-sculpting your brain with exercise.”

Exercise can benefit mental health, too

The brain benefits of exercise aren’t limited to structure and cognition. Exercise triggers the release of chemicals like endorphins, adrenaline, serotonin, and dopamine, which can improve mood and reduce stress levels.

Each of these chemicals plays a distinct role. Dopamine makes us feel good and motivated when we achieve a goal or enjoy something we like. Endorphins are produced in response to stress or discomfort, inducing pleasure and euphoria. Adrenaline boosts heart rate, blood pressure, and energy during high-stress or exciting situations. And serotonin regulates mood, appetite, sleep, and cognitive functions, contributing to feelings of well-being.

Chris Boyce, a former Florida hockey player who sustained significant brain injuries during his 28-year career, has experienced these mental health benefits firsthand. After years of depression, mood swings, and memory problems — and roughly 11 different medications — Boyce found that exercise helped more than any of them.

“I started exercising with them, and I started seeing the benefits,” Boyce told Being Patient, adding that it helped lessen his depression and anxiety. “It just makes me feel better in the morning. “I wish I would have stuck with diet and exercise first.”

How much exercise does the brain need?

The level of physical activity needed to support brain health may be lower than many people expect. You don’t need to run marathons or spend hours at the gym to see a meaningful effect on your brain.

According to leading neurology researchers, walking at least 10,000 steps per day can decrease a person’s risk of Alzheimer’s disease by as much as 60 percent. 

A large study published in JAMA Neurology found that walking was associated with a lower risk of developing dementia. Analyzing data from 78,430 adults ages 40 to 79 in the U.K. over seven years, researchers found that dementia risk appeared to decline as daily step counts increased, with the strongest benefit seen at about 9,800 steps per day, which was associated with a 51 percent lower risk. 

Even lower step counts were linked to benefit: about 3,800 steps per day was associated with a 25 percent lower risk. Walking intensity also mattered. People who accumulated more “purposeful” steps — defined as steps taken at 40 or more steps per minute — had lower dementia risk. The greatest reduction was seen among those who averaged about 112 steps per minute for at least a half an hour, a brisk pace associated with a 62 percent lower risk. 

Suzuki has pointed to research showing that regular walking alone can reduce the risk of developing dementia by about 30 percent. Even short bursts of moderate-to-vigorous activity throughout the day — sometimes called “exercise snacks” — may also have a positive impact on brain health. And even light physical activity has been linked to meaningful cognitive improvements.

The World Health Organization recommends that older adults get a minimum of 150 minutes per week of moderate-intensity aerobic exercise, combined with activities that maintain strength and flexibility.

Which types of exercise are best for brain health?

Research consistently suggests that aerobic exercise offers the strongest brain health benefits. Walking, running, cycling, swimming, and dancing all fall into this category.

But the science also supports a more varied approach. Experts highlight several categories of exercise that each contribute to brain health in different ways:

Flexibility exercise helps improve your joints’ range of motion and muscle elasticity, reduce muscle stiffness, and boost overall mobility. Researchers recommend 15 to 30 minutes at least three days a week, focusing on areas like the shoulders, back, calves, and hamstrings.

Strength training helps build and maintain muscle strength and mass, improves bone density, and enhances overall functional fitness. Sessions of 20 to 90 minutes are recommended, depending on the number of sessions per week. Key exercises include resistance training, push-ups, squats, and planks.

Balance exercises improve your sense of balance to enhance stability, coordination, and reduce the risk of falls, especially as you age. At least 45 minutes, three days a week is recommended, through activities like stretching, yoga, tai chi, and balance-specific training.

Certain activities may offer unique advantages because they engage the brain in multiple ways simultaneously. Ballroom dancing, for example, is both physically and cognitively demanding — it requires reacting to a partner’s movements, learning new steps, and remembering old ones. Yoga has been shown to benefit the hippocampus and the amygdala, the brain region that regulates emotion.

Physical inactivity is a recognized risk factor for dementia

“About 40 percent of all cases of dementia are due to modifiable risk factors.” Dr. Jason Hinman, a vascular neurologist and neuroscientist at UCLA, told Being Patient. He said these risk factors “include a Western diet rich in saturated fats, lack of exercise, poor sleep, and vascular risk conditions like high blood pressure, diabetes, and hyperlipidemia.”

The Lancet Commission on Dementia Prevention has identified physical inactivity as one of 14 modifiable risk factors that could collectively help prevent or delay up to 45 percent of dementia cases worldwide.

“In my own practice, I’ve been telling patients it would be a good idea to exercise regularly,” Eric Larson, a senior investigator at Kaiser Permanente Washington Health Research Institute and an author of the Lancet study, said. “When they found out that you could preserve your brain and reduce your risk of dementia, it was actually a powerful motivator for many people to become a regular exerciser.”

The U.S. POINTER study: A landmark trial

The U.S. POINTER study is the largest randomized trial to examine whether healthy lifestyle changes can help protect cognition in older adults at risk of cognitive decline.

The results, presented at the Alzheimer’s Association International Conference in July 2025, showed that a structured lifestyle intervention — including regular exercise, a healthy diet, cognitive and social engagement, and medical guidance — can improve brain health.

The study enrolled 2,111 participants ages 60 to 79. The structured group followed a weekly plan that included exercise sessions alongside other healthy behaviors like eating a balanced diet. They also attended 38 team meetings with other participants and facilitators. The trial’s unstructured program followed a self-guided approach where participants were encouraged to exercise and eat healthy, but only attended six team meetings.

Both groups showed improvement. But participants in the structured program — those with regular peer meetings, personalized goals, and support from study staff — experienced even greater cognitive gains.

“The extra benefit in cognition for the structured group was like slowing the cognitive aging clock by one to two years,” Laura Baker, the study’s lead investigator, told Being Patient.

Exercise may also help people already living with dementia

The benefits of physical activity extend beyond prevention. Research suggests that exercise can also help people who have already been diagnosed with cognitive impairment or dementia.

Suzuki has cited studies showing that even people aged 75 and older who have already been diagnosed with Alzheimer’s or dementia can benefit from a three-month exercise regimen. While those who did not exercise saw their dementia scores continue to rise, those who began exercising saw their scores improve.

“That says to me that you’re never too old to benefit from exercise,” Suzuki said.

UCSF neuropsychologist Kaitlin Casaletto and colleagues found similar associations in people with a genetic predisposition for frontotemporal dementia. In an observational study of 105 people with inherited FTD-related mutations, those who reported higher levels of physical and cognitive activity at the start of the study showed more than 55 percent slower clinical decline per year compared with less active participants.

A specialized exercise program has also been shown to alleviate neuropsychiatric symptoms like depression and anxiety in people with dementia.

How to get started

The most consistent advice from researchers is also the simplest: move your body regularly in ways that you enjoy.

“For everybody, I don’t care who you are, the best way to move your body is walking,” Suzuki told Being Patient. “We know that has an effect on long-term brain health, decreasing chances of dementia.”

For those looking to do more, experts suggest adding variety. Incorporating strength training, trying a new form of exercise, or engaging in activities that are both physically and socially stimulating — like dancing or group fitness classes — may enhance the brain’s response.

Exercise is not a guaranteed prevention for dementia, and researchers are still working to develop personalized exercise recommendations that optimize the impact on individual brain health. But the evidence linking exercise to brain health is among the most consistent in dementia research. It remains one of the most accessible and affordable strategies associated with healthier brain aging.