Moderate exercise also helps offset some of the increased stroke risk in women taking postmenopausal hormone therapy, researchers said. (Agencies)
"I was surprised that moderate physical activity was most strongly associated with a reduced risk of stroke," said Sophia Wang, the study's lead author and professor in the department of population sciences within the Beckman Research Institute at the City of Hope in Duarte, California.
"More strenuous activity such as running didn't further reduce women's stroke risk. Moderate activity, such as brisk walking appeared to be ideal in this scenario," Wang said.
Researchers analysed information from the 133,479 women in the California Teachers Study to see how many suffered a stroke between 1996 and 2010.
Those who reported doing moderate physical activity in the three years before enrolling in the study were 20 percent less likely than women who reported no activity to suffer a stroke.
"The benefits of reducing risk of stroke were further observed among the group of women who had a sustained moderate level of physical activity over time," Wang said.
Postmenopausal women taking menopausal hormone therapy had more than a 30 per cent higher risk of stroke than women who never used menopausal hormone therapy. After the women stopped taking hormones, their risk began to diminish.
"The effects of physical activity and hormone therapy appear immediate and the benefits of physical activity are consistent in premenopausal and postmenopausal women," Wang said.
The study, co-authored by Leslie Bernstein, James Lacey, and Kamakshi Lakshminarayan, among other researchers, also found that women with diabetes had elevated stroke risk, although this group encompassed women who also were overweight.
The research was presented at the American Stroke Association's International Stroke Conference 2014 in San Diego.
Moderate exercise also helps offset some of the increased stroke risk in women taking postmenopausal hormone therapy, researchers said.