How does exercise protect my heart?
The heart is like any other muscle—the more you work it, the stronger it gets. As the heart gets stronger, it is better able to pump blood around the body and to cope with the demands placed on it during physical exertion. Regular physical activity helps prevent some risk factors for heart disease including high blood pressure, high cholesterol, diabetes, and obesity. If you already have these risk factors, being active can stop them from getting worse. Exercise also keeps your arteries flexible (stiff arteries are prone to clogging) and can even reverse or stall the buildup of fatty plaques in the blood vessels of the heart.10, 11
Does exercise lower my risk of heart disease?
Yes. Moderate exercise (brisk walking) 30 minutes a day on most days of the week lowers your risk of developing heart disease or heart problems such as a heart attack by 30% to 50%.4, 12, 13 The Nurses' Health Study followed more than 70,000 women aged 40 to 65 for 8 years. It found that women who walked briskly for 1 to 3 hours a week were 30% less likely to develop heart disease compared with women who did no exercise.12 The Women's Health Initiative included more than 70,000 postmenopausal women. In this study, the most active women were half as likely to develop heart disease as the least-active women after about 3 years; active black women benefited just as much as active white women.13
Does exercise lower my risk of dying early?
Yes. An 11-year study of nearly 100,000 women aged 30 to 49 years from Norway and Sweden found that the most active women had half the risk of dying early than the least active women.14 You don't have to go for the burn to benefit. When nearly 14,000 women were followed for about 14 years, those who walked, cycled, or did light gardening 2 to 4 hours a week cut their risk of dying young by 36% compared with their sedentary peers.15 Older women reap the rewards, too. In a US study, postmenopausal women aged 55 to 69 years who were moderately active once a week were nearly 25% less likely to die within 7 years than women of the same age who were not active.16
If I was active in my youth but am inactive now, am I still protected?
No. Unfortunately, you can't store the heart healthy benefits of exercise. If you were active in your youth but do nothing now, you have the same risk of heart disease as a lifetime nonexerciser.17, 18 The good news is that it's never too late to start. Of the nearly 40,000 women in the Women's Health Study, those who became active at 45 years or older cut their risk of heart disease by about 25% compared with lifetime nonexercisers.17 Even older women can benefit, too. The Study of Osteoporotic Fractures enrolled nearly 10,000 women 65 years and older. Women who became more active between the start and end of the study (about 6 years later) nearly halved their risk of dying early compared with women who stayed inactive.19
Will I benefit from exercise if I already have heart disease?
Yes. For people who have had a heart attack, regular exercise cuts the risk of having another heart attack or dying from heart disease (see Physical Recovery After a Heart Attack or Procedure).20, 21 If you have clogged arteries, you may feel chest pain ( angina) during exertion; however, regular exercise actually relieves this chest pain in the long term. Exercise combined with diet and lifestyle changes can help slow down or even reverse the buildup of fatty plaque in the arteries of the heart.22, 23 If you have heart disease, talk to your healthcare provider before starting an exercise program. Your doctor may refer you to a cardiac rehabilitation program that includes supervised exercise, nutritional counseling, stress management, and modification of risk factors.