Men who regularly take part in moderate-to-heavy intensity exercise such as jogging, tennis or swimming may be less likely to have a stroke than people who get no exercise or only light exercise, such as walking, golfing, or bowling, according to a study published in the November 24, 2009, print issue of Neurology®, the medical journal of the American Academy of Neurology.

However, exercise did not have a protective effect against stroke for women. Women who took part in moderate-to-heavy intensity exercise did not have a reduced risk of stroke.

The study involved 3,298 people living in northern Manhattan, NY, with an average age of 69 who were followed for about nine years. During that time, there were 238 strokes. A total of 41 percent of the participants reported that they participated in no physical activity. Twenty percent regularly participated in moderate-to-heavy intensity activities.

Men who participated in moderate-to-heavy intensity activities were 63 percent less likely to have a stroke than people with no physical activity. The baseline risk of ischemic stroke over five years in the entire group was 4.3 percent; among those with moderate-to-heavy intensity activities the risk was 2.7 percent, and among those with no activity it was 4.6 percent.

"Taking part in moderate-to-heavy intensity physical activity may be an important factor in preventing stroke," said study author Joshua Z. Willey, MD, of Columbia University Medical Center and New York Presbyterian Hospital at Columbia. Willey is also a member of the American Academy of Neurology. "A large percentage of the participants were not taking part in any physical activities. This may be true of many elderly people who live in cities. Identifying ways to improve physical activity among these people may be a key goal for public health."

These results are contrary to some other studies that found that even light intensity physical activity reduced the risk of stroke. Willey said the number of participants may not have been large enough to detect subtle differences in the group that took part in only light physical activity.

Stroke is the leading cause of disability and the third-leading cause of death in the United States.

The study was supported by the National Institutes of Health.