• Posted August 20, 2026

Why You Move Matters When It Comes To Brain Health, Dementia Risk

It’s been said that regular physical activity can help lower risk of dementia, but a new evidence review suggests that why you move also matters.

Leisure-time exercise like walking, cycling, running, swimming or playing sports is associated with a much lower risk of dementia, researchers report in the September issue of The Lancet Public Health.

But physical activity performed on the job appears to be linked to a higher risk of dementia, researchers found.

“The findings challenge the long-held assumption that ‘every move counts’ for brain health,” lead researcher Natan Feter said in a news release. He’s a postdoctoral fellow at the University of Southern California.

For the review, researchers analyzed data from 74 prior studies involving more than 4.2 million people ages 45 to 93 across 30 countries. The study group was followed for a median of 10 years to see who developed dementia. (This means that half were followed longer, half for a shorter time.)

Results showed that people who had higher levels of leisure-time physical activity had a 24% lower risk of dementia than those who were least active.

But physical activity on the job was associated with a 20% higher dementia risk, researchers found.

Physically demanding jobs can involve repetitive tasks, prolonged standing, heavy lifting and limited recovery time, researchers noted.

However, researchers theorize it’s unlikely the on-the-job movement caused the increased risk of dementia found in the study. Instead, the observed risk is more likely due to social and environmental conditions that often accompany labor-intensive jobs.

Manual labor is more likely to involve stress, hazardous working conditions and greater exposure to pollution, all of which have been linked to dementia risk, researchers said.

Workers in physically demanding jobs might also have fewer opportunities for recreational exercise because they don’t have enough spare time or are simply too fatigued once they’re off the clock, researchers added.

“In other words, when it comes to protecting the brain, the context of physical activity may matter just as much as movement itself,” senior researcher David Raichlen said in a news release. He is a professor of human and evolutionary biology and anthropology at the University of Southern California.

“Improving access to safe parks, walking trails and recreational facilities, ensuring people have adequate leisure time for exercise, and reducing harmful workplace exposures may ultimately prove as important as promoting physical activity itself,” he said.

More information

The Alzheimer’s Society has more on physical activity and dementia risk.

SOURCE: University of Southern California, news release, Aug. 18, 2026