Being physically active between the ages of 45 and 65 could help protect your brain and reduce the chances of developing Alzheimer’s disease.
That’s the main message from a new study published in the journal Alzheimer’s & Dementia, led by researchers from the Barcelona Institute for Global Health and the Barcelonaβeta Brain Research Center in Spain.
The research supports the idea that regular movement and exercise during midlife is not just good for your heart and mood—it may also protect your memory and brain function in the long term.
Alzheimer’s disease is the most common form of dementia, and it affects millions of people worldwide. Although age and genetics are major risk factors, lifestyle habits like physical activity play a big role too. It’s estimated that about 13% of Alzheimer’s cases globally could be linked to not being active enough.
That’s why the World Health Organization recommends that adults aim for at least 150 to 300 minutes of moderate activity—or 75 to 150 minutes of intense activity—each week.
Past research has shown that regular exercise helps prevent Alzheimer’s by supporting good blood flow and mental health. But this new study goes further, suggesting that physical activity may also directly affect the changes in the brain that are linked to Alzheimer’s disease.
The study followed 337 people from Catalonia, Spain, over four years. All of them were in middle age and had a family history of Alzheimer’s, which increased their risk.
The team collected data on their physical activity levels through questionnaires and also scanned their brains using imaging tests to look for signs of Alzheimer’s, such as the buildup of beta-amyloid protein and thinning in certain brain areas.
Participants were grouped into three categories: those who met the WHO’s physical activity guidelines, those who did some activity but didn’t meet the full recommendations, and those who were completely inactive.
The results were encouraging. People who increased their physical activity over the four years had less buildup of beta-amyloid, a protein that can clog brain cells and is one of the earliest signs of Alzheimer’s. The more they exercised, the less beta-amyloid they had—suggesting that the effect is dose-dependent.
In addition, those who moved more had thicker brain regions in the medial temporal lobe, which is key for memory. Thinner brain tissue in this area is an early sign of brain degeneration.
Interestingly, even those who didn’t reach the recommended amount of exercise still had thicker brain regions than those who were completely inactive, showing that even a small amount of movement is better than none.
One key takeaway from the research is that it’s not only about hitting a certain number of hours of exercise per week. What matters most is whether you increase your activity over time. Building better habits in middle age—even gradually—can make a real difference in brain health.
The study’s lead author, Dr. Eider Arenaza-Urquijo, emphasized the importance of promoting physical activity as a public health measure. Encouraging people to move more during their middle years could be a powerful way to lower the number of Alzheimer’s cases in the future.
In short, this research shows that staying active in midlife can help the brain stay healthier longer. Whether it’s walking, cycling, dancing, or swimming—any movement is better than none. Building a habit of physical activity today could be one of the best ways to protect your brain for tomorrow.
If you care about Alzheimer’s, please read studies about the likely cause of Alzheimer’s disease , and new non-drug treatment that could help prevent Alzheimer’s.
For more information about brain health, please see recent studies about diet that may help prevent Alzheimer’s, and results showing some dementia cases could be prevented by changing these 12 things.
The research findings can be found in Alzheimer’s & Dementia.
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