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.

A small weekly dose of moderate to vigorous exercise could significantly lower an older adult’s chances of developing dementia.

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.