A study in the journal Stroke says people who are inactive -- exercising less than once a week -- are 20 percent more likely to have a stroke.
That's compared to people who exercise at least four times a week.
Stroke is the fourth leading cause of death in the United States.
The National Institutes of Health describe a stroke as occurring when blood vessels that supply the brain become ruptured or blocked. As a result, brain cells die from lack of oxygen and other nutrients.
The five-year study looked at 27,000 black and white participants, men and women, from across the nation. They had no prior history of stroke, and were at least 45 years old.
The bottom line: Researchers concluded exercise reduces blood pressure, weight and diabetes -- all risk factors for strokes.