Even Low-Intensity Exercise May Help Prevent Alzheimer’s

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On April 26, 2025

Light exercise like stretching and balance training can be just as effective as sweatier workouts for keeping the brain healthy and protecting against Alzheimer’s disease, according to new research.

Findings from the study suggest that regular exercise, even at low intensity, could go a long way toward helping older adults slow or delay cognitive decline — promising news for people at risk for dementia.

While earlier research has shown that physical activity can help prevent cognitive decline and dementia, this investigation zeroed in on older adults who already had mild cognitive impairment. It is part of the EXERT study (Exercise in Adults With Mild Memory Problems), the largest rigorous trial of exercise ever conducted in adults with mild cognitive impairment.

Mild cognitive impairment, or MCI, is the stage between normal thinking skills and dementia. It comes with some memory loss and language issues, but it doesn’t impact day-to-day living.

People with mild cognitive impairment are more likely to progress to dementia, but some people with MCI never get worse, and in some cases, their brain health may even improve.

Low-Intensity Activity Prevented Brain Shrinkage

The study included nearly 300 older adults with MCI who didn’t exercise regularly. Participants were placed in one of two groups:

Moderate-high intensity: Moderate-high intensity aerobic training, mainly treadmill walking
Low intensity: Stretching, balance, and light resistance exercise using resistance bands

Everyone in the study exercised three to four times per week for 12 months under the supervision of a YMCA trainer.

The study included regular assessments of cognitive function and brain volume, which researchers compared with an existing dataset of comparable individuals who received only usual care, such as regular checkups with healthcare providers and medication management.

Investigators expected to see cognitive decline in the low-intensity exercisers compared with the moderate- to high-intensity exercisers, but that didn’t happen.

Key study findings:

Cognitive function remained stable over 12 months in both exercise groups.
Participation in either exercise group was associated with significantly less cognitive decline over 12 months than in individuals outside the study.
Both exercise groups tended to show less loss of brain volume over 12 months, including in the prefrontal cortex, the part of the brain responsible for decision-making, personality, and executive function.

“One of the more interesting findings from the trial was that exercise not only slowed cognitive decline but also appeared to slow underlying brain changes commonly associated with Alzheimer’s risk,” says Patrick J. Smith, PhD, MPH, an associate professor of psychiatry at the UNC School of Medicine in Chapel Hill, North Carolina, who was not involved in the study.

You Don’t Have to Sweat to Improve Brain Health

“We are hopeful that even lower intensity exercise could have benefits for brain health,” says Laura Baker, PhD, the principal investigator of the EXERT study and a professor of gerontology and geriatric medicine at Wake Forest University School of Medicine in Winston-Salem, North Carolina.

“Although moderate- to high-intensity exercise often has been touted as the minimum amount needed to support memory and thinking abilities in the past, this level of intensity may not be attainable for all older individuals. Our findings suggest that any exercise, if done regularly, could have benefits for cognition,” says Dr. Baker.

For people who are able to ramp up the intensity, that may be even better for overall health and brain health.

“The recommended aerobic exercise dose is moderate exercise at least 30 minutes per day, or 150 minutes per week, including 75 minutes of vigorous exercise, but any kind of movement will protect your brain health, will improve your mood and mental health, and prevent cognitive decline,” says Helen Lavretsky, MD, a professor in residence in the department of psychiatry and a geriatric integrative psychiatrist at the University of California in Los Angeles, who was not involved in the study.

Experts Agree: Consistency Is Key

One takeaway for folks at risk for cognitive decline is that consistency is crucial, says Dr. Smith.

“I am asked every week, ‘What type of exercise should I do to help keep my brain healthy?’ These findings underscore the message I often give: The exercise you should do is the one that you’ll actually do. Anything is better than nothing, and prioritizing consistency over intensity is key. Making lifestyle changes you can stick with, however small, is a key starting point,” he says.

Find a Friend and Seek Out Joy

Baker agrees that it’s important to find an activity you enjoy. She also suggests building in an accountability factor, either by connecting with an exercise buddy or working with a fitness trainer.

“If a person has some memory problems, even if mild, it will be important to find extra support to ensure that the exercise remains regular, as these individuals have more difficulty initiating and sticking to activities that can be challenging at times,” Baker says. “Social environments can add to the benefits of exercise, such as community facilities like the YMCA, which has wonderful older adult programs.”

If you add an element of joy to the exercise, sticking to it will be easier, says Dr. Lavretsky. “You can dance and get additional benefit from moving with music, or hike in nature and benefit from earthing or forest bathing. Or do anything that makes your spirit soar. Add life to years, not just years to life,” she says.