New research brings promising news for older adults with mild memory problems: regular exercise, even at low intensity, may protect against cognitive decline.
Scientists from the University of California San Diego and Wake Forest University have discovered that both low and moderate-intensity exercise regimens appear to help maintain cognitive function in older adults with amnestic mild cognitive impairment (aMCI), a condition that increases Alzheimer’s disease risk.
The findings, published April 24 in Alzheimer’s & Dementia, revealed that participants who completed supervised exercise programs at local YMCAs showed significantly less decline in cognitive function compared to similar individuals who received only usual medical care.
“This is a critical time to intervene in this population, because they don’t have dementia yet, but are at a very high risk,” said Aladdin Shadyab, lead author of one of the papers and associate professor at UC San Diego. “Together, these findings show us that even low intensity exercise may slow cognitive decline in at-risk older adults.”
The research emerged from the EXERT study, a 12-month multi-site randomized controlled trial involving nearly 300 sedentary adults aged 65-89 with aMCI. Participants were randomly assigned to either moderate-high intensity aerobic training or lower-intensity stretching, balance, and range of motion activities.
What surprised researchers was that both exercise groups maintained stable cognitive function over the year-long study. This contrasted with the expected decline seen in a matched comparison group from an observational study who received only standard medical care.
Brain imaging showed trends suggesting both exercise groups experienced less volume loss in the prefrontal cortex, a region critical for planning and decision-making. The moderate-intensity group also showed significantly less volume loss in the entorhinal cortex, an area involved in memory that typically deteriorates early in Alzheimer’s disease.
The study design included careful matching of participants across groups based on age, sex, race, education level, and genetic risk factors. This strengthens confidence that the differences observed were due to the exercise interventions rather than other factors.
Howard Feldman, director of the Alzheimer’s Disease Cooperative Study at UC San Diego, emphasized the practical implications: “EXERT was one of the first large clinical trials of exercise that partnered with the YMCA and its trainers to bring the intervention closer to home for research participants. This approach brings us one step closer to its implementation in the community.”
The findings carry particular weight because individuals with aMCI progress to Alzheimer’s dementia at a rate of approximately 16% per year, creating an urgent need for interventions that could slow or prevent this transition.
Laura Baker, principal investigator of the EXERT study and professor at Wake Forest University School of Medicine, underscored the significance: “EXERT is a landmark study because it’s the largest rigorous trial of exercise ever conducted in adults with mild cognitive impairment. Exercise has well-documented benefits to nearly every aspect of human health, but we’re still unlocking the full potential of exercise as medicine for older adults with memory problems.”
The researchers note that the supervision aspect may have been crucial for maintaining proper exercise form and adherence. Participants exercised 3-4 times weekly for 45 minutes per session under YMCA trainer guidance.
While previous research has produced mixed results regarding exercise’s cognitive benefits, this study’s size, duration, and rigorous design provide compelling evidence that regular physical activity may help preserve brain function in those at heightened dementia risk.
The study protocol purposely included a lower-intensity exercise group rather than a non-exercise control, as researchers felt ethically obligated to provide active options for all participants given exercise’s known health benefits.
For the estimated 2.4 million Americans currently living with mild cognitive impairment due to Alzheimer’s disease—a number projected to reach 5.7 million by 2060—these findings offer a practical, accessible intervention that could potentially alter disease trajectory.
Experts emphasize that the supervised nature of the program likely contributed to its success. Participants received proper guidance on form and intensity, with regular monitoring of heart rate and perceived exertion during sessions.
Whether the cognitive benefits persist beyond the 12-month supervised period remains to be seen, though researchers continue to track participants to assess longer-term outcomes.
As the search for effective Alzheimer’s interventions continues, this research suggests that something as simple and accessible as regular exercise might provide meaningful protection for those at risk.
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