March 5, 2025
Don’t like to exercise? Even a few minutes a day of moderate to vigorous physical activity may help to lower your risk of developing Alzheimer’s disease.
Those are the findings of a new analysis from scientists at the Johns Hopkins Bloomberg School of Public Health. For their study, the researchers looked at nearly 90,000 men and women living in the U.K. who wore smart-watch-type activity trackers. Most were in their 50s and older.
The researchers tracked their health over an average follow-up period of 4.4 years. During that time, 735 developed Alzheimer’s disease or other forms of dementia.
Compared to their sedentary peers, study participants who engaged in as little as 35 minutes a week of moderate to vigorous physical activity had a 41 percent lower risk of developing dementia. Even frail, elderly adults, who are at high risk of a range of medical problems, appeared to show brain benefits from just a short period of daily exercise.
“Our findings suggest that increasing physical activity, even as little as five minutes per day, can reduce dementia risk in older adults,” said Amal Wanigatunga, the study’s lead author and an assistant in the Bloomberg School’s Department of Epidemiology. “This adds to a growing body of evidence that some exercise is better than nothing, especially with regard to an aging-related disorder that affects the brain that currently has no cure.”
And the more people exercised, the greater the potential benefits. Those who got 35 to 70 minutes a week of exercise had a 60 percent lower risk of dementia, while those who exercised for 70 to 140 minutes a week had a 63 percent lower risk. Those who exercised 140 or more minutes a week had a 69 percent lower risk of dementia than those who got no exercise. The findings were published in the Journal of the American Medical Directors Association.
Both the U.S. Department of Health and Human Services and the U.K. National Health System recommend that adults get at least 150 minutes of moderate intensity exercise per week, an average just over 20 minutes per day. But prolonged exercise can be especially difficult for frail, older adults.
These new findings underscore that any type of exercise, even a few minutes a day of moderate activity, can have profound benefits for brain health. Moderate activities raise your heart rate and breathing rate slightly and include walking, gardening, swimming, dancing or doing household chores. Vigorous exercise generally makes you breathe hard or sweat and includes activities like jogging, running, aerobics classes, or team sports like soccer or basketball.
The findings add to growing evidence that exercise isn’t just good for bulking up muscles; it may also help to bulk up our brains. Other studies have shown that people who are physically active in midlife tend to perform better on tests of memory and thinking skills and are nearly half as likely to eventually develop Alzheimer’s disease later in life than their peers who rarely exercise. People in their 70s who walked several times a week had less brain shrinkage and other signs of aging in the brain than those who were less physically active.
Alzheimer’s is a complex disease that depends on many factors, including the genes you inherit, and regular exercise is likely just one part of the preventive puzzle. While a daily walk around the mall or a swim at your local Y won’t guarantee a physically and mentally robust old age, it may help you to look, feel and act younger.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D. Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Amal Wanigatunga, Yiwen Dong, Mu Jin, et al: “ Moderate-to-Vigorous Physical Activity at Any Dose Reduce All-Cause Dementia Risk Regardless of Frailty Status.” Journal of the American Medical Directors Association, January 15, 2025.
