A new study from Spain suggests that increasing physical activity between ages 45 and 65 could help prevent Alzheimer’s disease—proving the importance of exercise in the aging brain.

Published in Alzheimer’s & Dementia, the study tracked 337 middle-aged adults, many with a family history of Alzheimer’s. Over four years, researchers from Barcelona Institute for Global Health (ISGlobal) and the Barcelonaβeta Brain Research Center (BBRC) found that those who increased their physical activity had less beta-amyloid buildup (a key early marker of Alzheimer’s) and thicker brain cortices in areas tied to memory.

“We used physical activity questionnaires to assess changes in activity… and neuroimaging tests to analyze the effects of exercise on brain structure and function,” said Müge Akıncı, the study’s first author.

Even those who exercised less than the WHO-recommended 150 minutes per week (note that this is not an excuse to not meet the recommendations) had healthier brain structures than people who were completely inactive.

“Even those who did less physical activity than recommended had greater cortical thickness than sedentary people, suggesting that any amount of exercise, no matter how minimal, has health benefits,” Akıncı explained.

The benefits weren’t just tied to hitting a weekly exercise quota—it was the increase in activity over time that mattered most. People who moved more over the study period saw the greatest reduction in Alzheimer’s-related brain changes.

“These findings reinforce the importance of promoting physical activity in middle age as a public health strategy for Alzheimer’s prevention,” said lead investigator Eider Arenaza-Urquijo.

Exercise more! Exercise more! Exercise more! Study highlights the importance of exercise in preventing dementia while also increasing the volume of exercise as we age.

M Akinci et al. Physical activity changes during midlife link to brain integrity and amyloid burden. Alzheimer’s & Dementia (2025). https://doi.org/10.1002/alz.70007