Want to protect your aging brain? Get off the couch and get moving, researchers urge.

Boosting exercise in middle age might help people prevent Alzheimer’s disease, a new study says.

Editor's Note: Over 50? Serious Brain Nutrition Combats Scary Mental Decline

People who increased their physical activity to meet recommended guidelines between ages 45 and 65 had less accumulation of amyloid beta, a toxic protein that forms plaques in the brains of Alzheimer’s patients, researchers reported April 30 in the journal Alzheimer’s & Dementia.

The link was dose-dependent, researchers added — the more people increased their activity, the greater the reduction in amyloid beta in their brains.

Active people also showed less age-related shrinkage in brain regions associated with memory and Alzheimer’s, researchers noted.

“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,” lead investigator Müge Akinci, a researcher with the Barcelona Institute for Global Health in Spain, said in a news release.

It’s estimated that 13% of Alzheimer’s disease cases worldwide can be attributed to physical inactivity, researchers said in background notes.

For the study, researchers tracked the brain health of 337 people in Catalonia, Spain, who were participating in a long-term study of Alzheimer’s disease.

“We used physical activity questionnaires to assess changes in activity over a four-year period and neuroimaging tests to analyze the effects of exercise on brain structure and function,” Akinci said.

The people were classified based on physical activity guidelines recommending 150 to 300 minutes of moderate activity per week or 75 to 150 minutes of vigorous exercise.

The benefits of physical activity appear to be related to increasing activity over time, rather than reaching a certain exercise threshold, researchers added.

“These findings reinforce the importance of promoting physical activity in middle age as a public health strategy for Alzheimer's prevention,” said senior investigator Eider Arenaza-Urquijo of the Barcelona Institute for Global Health.

“Interventions aimed at promoting increased physical activity could be key to reducing the incidence of the disease in the future,” Arenaza-Urquijo concluded in a news release.