The Effects of Exercise on Your Brain

June 21, 2017 | Family Medicine • Internal Medicine • Sports Fitness and Physical Therapy

A condition that becomes more common with age and is often associated with the aging process is dementia, an impaired ability to think and recall. Dementia’s primary cause, Alzheimer’s disease, and several other thinking and memory issues (called mild cognitive impairment), are issues that researchers have spent numerous resources looking for better combatants against.

Despite all the efforts of various researchers, doctors and drug companies, no known drug or therapy has been able to match the powerful effect of regular physical exercise. Regular exercise has been shown to help prevent Alzheimer’s disease and improve brain function, even among people who already have Alzheimer’s disease.

Statistics

One Mayo Clinic study showed that people who regularly engaged in moderate exercise five or six times per week later in life reduced their risk of mild cognitive impairment by 32 percent compared with more inactive people. People who began exercising earlier, in midlife, saw a 39 percent reduction in mild cognitive impairment risk.

Researchers at the University of British Columbia found that regular aerobic exercise appears to boost the size of the hippocampus—the part of the brain involved in verbal memory and learning. Another study found that the effect of exercise on people with memory issues was about as good as the documented benefit of donepezil, a drug that can help with mild cognitive decline.

How it Works

Through direct and indirect means, exercise assists with both memory and thinking. Exercise reduces insulin resistance, reduces inflammation and stimulates the release of growth factors. These growth factors are chemicals in the brain that affect the health of brain cells, the growth of new blood vessels in the brain and the abundance and survival of new cells.

In addition, exercise may help improve levels of brain connections. A substance like brain-derived neurotrophic factor (BDNF) can be very helpful for helping the brain make new connections, and these levels are commonly lower in people with Alzheimer’s disease—exercise appears to directly increase BDNF levels.

More indirectly, exercise helps improve mood and sleep, along with stress and anxiety reductions. These areas can often contribute to cognitive impairment. Many studies have indicated that the parts of the brain that control thinking and memory have greater volume among people who exercise compared to those who don’t.

The Right Amounts

Most studies that have been done in this area have been for walking, and researchers consider this moderate intensity exercise. Standard recommendations include half an hour of moderate physical activity on most days of the week, or 150 minutes per week. Some people have to start at lower totals and work their way up, and this is fine.

If you don’t want to walk, consider other moderate-intensity exercises: Swimming, tennis, stair climbing, squash or dancing. Certain household activities or chores can count as well, as long as they get the heart pumping and cause a light sweat. If you need help with motivation, consider joining a class, working out with a friend, tracking your progress to reach goals, or even hiring a personal trainer.

If you have specific questions about what sort of exercise is best for you and any precautions you should take, your doctor can offer recommendations based on your specific case.