"I was surprised that moderate physical activity was most strongly associated with a reduced risk of stroke," said Sophia Wang, Ph.D., 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, Calif. "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."

The study found that moderate exercise also helps offset the increased stroke risk seen with postmenopausal women taking menopausal hormones, but not completely.