Exercise extends average life spans (but not maximum life spans) in laboratory animals and improves long term health. In human epidemiological studies it is associated with better health and greater life expectancy. Here is another of the many, many examples of this relationship:
In a study of more than 27,000 Americans, 45 years and older who were followed for an average of 5.7 years, researchers found: 1) One-third of participants reported being inactive, exercising less than once a week. 2) Inactive people were 20 percent more likely to experience a stroke or mini-stroke than those who exercised at moderate to vigorous intensity (enough to break a sweat) at least four times a week. 3) Among men, only those who exercised at moderate or vigorous intensity four or more times a week had a lowered stroke risk. 4) Among women, the relationship between stroke and frequency of activity was less clear.
"The stroke-lowering benefits of physical activity are related to its impact on other risk factors. Exercise reduces blood pressure, weight and diabetes. If exercise was a pill, you'd be taking one pill to treat four or five different conditions." The study - the first to quantify protective effects of physical activity on stroke in a large multiracial group of men and women in the United States - supports previous findings that physical inactivity is second only to high blood pressure as a risk factor for stroke.