According to a new study in the New England Journal of Medicine, brisk walking is just as good for your heart as strenuous exercise, reports CBS News Health Contributor Dr. Bernadine Healy.
Walking briskly for three hours each week, or 25 minutes a day, can reduce a woman's risk of heart disease by 30 to 40 percent, according to the study.
Researchers at Brigham and Women's Hospital and Harvard Medical School tracked more than 121,000 female registered nurses from ages 40 to 65.
"Increasing walking time, or combining walking with vigorous exercise, appears to be associated with even greater risk reductions," according to the research team, led by Dr. JoAnn Manson of Brigham and Women's Hospital.
Heart attacks strike about 74,000 U.S. women between the ages of 45 and 64 each year, according to the American Heart Association. Experts say a sedentary lifestyle is just as dangerous to the heart as cigarette smoking or high blood pressure, reports Correspondent Dr. Dave Hnida of CBS Station KCNC-TV in Denver, Colo.
Doctors have known for years that you can sweat away part of your risk for heart disease, but most of the research has been done on men. This is the first large study that focuses on whether walking is as effective as a vigorous workout in preventing heart attacks.
The study found women who walked at leisurely speeds of less than 2 mph cut their heart disease risk by 25 percent. Yet, when the pace was 3 mph or greater, the risk of a heart attack declined by 36 percent.
Strolling or window shopping won't cut it, but it isn't necessary to become a power walker. On average, it takes 20 minutes to cover a mile for brisk walkers and 25 for casual walkers.
The results were less clear when the researchers compared brisk walking with exercise that required more energy.
For every 1.5 hours of brisk walking, the risk of a heart attack declined by 16 percent, the researchers found. When the same amount of energy was used by 45 minutes of jogging, bicycling, lap swimming or tennis, the risk declined by only 6 percent.
But the study does indicate that the two styles of exercise are "very similar... Walking can reduce the risk of heart attack to the same degree as vigorous exercise," Manson said.
Walking works because it lowers blood pressure and cholesterol, reduces blood clotting and blood sugar, and increases the body's sensitivity to insulin, all of which make heart disease less likely, she said.
"These findings lend further support to current federal exercise guidelines, which endorse moderate-intensity exercise for at least 30 minutes on most (preferably all) days of the week." Manson and her colleauges concluded.
The guidelines can be applied to women of all ages. The study found women who took up a walking program after menopause still cut their risk of heardisease.