New research found that working out starts a chain reaction that can lower your risk of dementia. Here's exactly how it works—and how long it takes.

Protect your brain health by reducing dementia risk. Small amounts of physical activity can lead to big benefits for older adults.

Just five minutes of exercise, that is moderate to vigorous, daily can help the elderly stave off the risk of dementia, according to a study. Researchers from the Johns Hopkins University in the US showed that engaging in as little as 35 minutes of moderate to vigorous physical activity per week,

Dementia benefits from physical exercise, and even brief periods of activity that people may dismiss as insufficient can help reduce the risk.