Women who walk at least three hours every week are less likely to suffer a stroke than women who walk less or not at all, according to new research from Spain.
"The message for the general population remains similar: regularly engaging in moderate recreational activity is good for your health," lead author José María Huerta of the Murcia Regional Health Authority in Spain told Reuters Health.
Past studies have also linked physical activity to fewer strokes, which can be caused by built-up plaque in arteries or ruptured blood vessels in the brain.
While the current study cannot prove that regular walking caused fewer strokes to occur in the women who participated, it contributes to a small body of evidence for potential relationships between specific kinds of exercise and risk for specific diseases.
Women who walked briskly for 210 minutes or more per week had a lower stroke risk than inactive women but also lower than those who cycled and did other higher-intensity workouts for a shorter amount of time.
In all, nearly 33,000 men and women answered a physical activity questionnaire given once in the mid-1990s as part of a larger European cancer project. For their study, Huerta and his team divided participants by gender, exercise type and total time spent exercising each week.
The authors, who published their findings in the journal Stroke, checked in with participants periodically to record any strokes. During the 12-year follow-up period, a total of 442 strokes occurred among the men and women.
The results for women who were regular walkers translated to a 43 percent reduction in stroke risk compared to the inactive group, Huerta said.
There was no reduction seen for men based on exercise type or frequency, however.
"We have no clear explanation for this," Huerta wrote in an email. He hypothesized that the men may have entered the study in better physical condition than the women, but there was no evidence to support that guess.
Huerta also declined to compare the study participants' risk levels to those of the general population, citing the subjects' unusual characteristics: a majority of men and women in the study were blood donors, who tend to be in good health in order to give blood.
"I wouldn't make much of the results because they are for a very specific population," Dr. Wilson Cueva of the University of Chicago in Illinois said.
Cueva, who was not involved with the research, pointed out that the study relied too heavily on subjective measurements, like the participants' memory of exercise routines.
"There is no objective way to measure how much exercise they actually did," he said.
Each year in the U.S., about 795,000 people suffer a stroke, according to the American Heart Association. Put another way, one American has a stroke every 40 seconds and dies from one every four minutes.
Despite a recent dip in strokes attributed to better blood pressure control and anti-smoking campaigns, the World Health Organization (WHO) predicts that stroke cases will increase as the global population continues to grow older.
Guidelines set by the WHO and U.S. Centers for Disease Control and Prevention recommend at least 150 minutes – or two-and-a-half hours – of moderate exercise such as brisk walking each week.
Cueva urged health consumers to heed those guidelines for now. The way the Spanish study was designed, it's difficult to draw any conclusions he told Reuters Health. But, "We know that exercise is related to reduced risk of stroke and other diseases."