Exercise Can Help to Cut Stroke Risk
Take a brisk walk. Climb the stairs at work. Dance the polka.
If you engage in these and other kinds of exercise for an hour a day, you can cut your risk for stroke by nearly half, according to a report in Stroke: Journal of the American Heart Association.
In the Harvard Alumni Health Study, researchers tracked the health of people who graduated from Harvard between 1916 and 1950. In the study, researchers looked at physical activity and followed men from 1977 until 1990, to see which of them had strokes.
Researchers found that people who burned 2,000 calories a week—briskly walking an hour a day, five days a week, for instance—had a 46 percent lower risk of stroke than those who got little to no exercise. People who burned 1,000 calories a week—walking briskly 30 minutes a day, five days a week—had about a 24 percent decrease in stroke risk.
"Not only did we find that physical activity is associated with reduced risk of stroke, but also we have some ideas as to how much and what type of activity might work best," says the study's lead author, I-Min Lee, M.D., of the Harvard School of Public Health.
The research backed the Surgeon General's recent report on physical activity, which called for at least 30 minutes of moderate intensity physical activity a day, most days of the week.
Dr. Lee says that physical activity can help reduce or eliminate other common stroke risk factors, including high blood pressure, high levels of blood cholesterol, obesity, and diabetes.
Even moderate activity is helpful
Dr. Lee and her co-author, Ralph Paffenbarger Jr., M.D., an internationally known exercise authority, found that moderate to vigorous activity had a positive effect on stroke risk. Moderate activity is defined as 4.5 times the energy use burned at rest.
"Walking, stair-climbing and participating in moderately intense activities such as dancing, bicycling and gardening were shown to reduce the risk of stroke," says Dr. Lee. "Light activity such as bowling and general housekeeping activity did not have the same effect."
Strokes, the leading cause of disability in the United States, occur when blood flow to the brain is blocked by a blood clot. They also can occur when fat-filled plaque clogs the vessels leading to the brain.
Although this study looked almost exclusively at white men and whether a link existed between physical activity and stroke, Dr. Lee says the research findings probably apply to women and minorities. A previous study in northern Manhattan had shown similar results in women and minorities.
The researchers took into account risk factors such as smoking, alcohol consumption, height and weight, high blood pressure, and diabetes. They still found that physical activity by itself was associated with decreased risk for stroke.