Regularly working out at moderate to vigorous intensity appears to reduce the risk of stroke, according to a study.
Researchers examined records of more than 27,000 Americans, ages 45 and older, who were followed for an average of 5.7 years.
As published July 18 on the website of the journal Stroke, the researchers found that a third of participants reported being inactive, exercising less than once a week.
Inactive people were 20% 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.
Among men, only those who exercised at moderate or vigorous intensity four or more times a week had a lowered stroke risk. Among women, the relationship between stroke and frequency of activity was less clear — possibly because women gain a benefit with less vigorous exercise such as walking, which was not a focus of this analysis, the researchers noted.
The researchers said the study, described as the first to quantify the 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 hypertension as a risk factor for stroke.
“The stroke-lowering benefits of physical activity are related to its impact on other risk factors,” Michelle McDonnell, PhD, study author and a lecturer at the University of South Australia, said in a news release. “Exercise reduces blood pressure, weight and diabetes. If exercise was a pill, youd be taking one pill to treat four or five different conditions.”
Study participants were part of the Reasons for Geographic and Ethnic Differences in Stroke (the REGARDS study). They were divided relatively equally between black and white and male and female, with more people from the “Stroke Belt” states in the southeast. The stroke belt is an area of the country where strokes are more common, and includes Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee and Virginia.
The study included self-reported data on the frequency of exercise, but not how long people were physically active each day. “We still need good studies on the amount you can reduce your risk stroke by taking up exercise,” McDonnell said.
According to the American Heart Association, healthy adults ages 18 to 65 should get at least 30 minutes of moderate-intensity physical activity at least five days a week, or at least 20 minutes of vigorous-intensity physical activity at least three days a week. Adults should also get at least two days a week of muscle-strengthening activities that involve all the major muscle groups.
Download a PDF of the study: http://stroke.ahajournals.org/content/early/2013/07/18/STROKEAHA.113.001538.abstract.