Being physically active can increase your life span, regardless of any “bad genes” you might have inherited. At any age, exercise protects against a multitude of chronic health problems, including cardiovascular disease. It helps control your weight and improve your blood pressure, lipid levels, clotting factors, inflammation, and overall health of your blood vessels.
Physical activity can lower your risk of developing type 2 diabetes by making muscle cells more sensitive to insulin produced by your body. In the federal Diabetes Prevention Program, modest lifestyle changes delayed or prevented the onset of type 2 diabetes by 58% — a better rate than that achieved with the diabetes drug metformin.
Exercise can also overcome the tendency of low-fat, lower-calorie diets to reduce levels of HDL cholesterol, especially in women. In the classic Stanford Weight Control Project, HDL levels in women on a low-fat diet fell 7% over the course of a year. But women who combined diet and exercise — about 8 miles of walking or jogging a week — increased their HDL levels in addition to losing weight and lowering their levels of total and LDL cholesterol. In men, a low-fat diet didn’t change HDL levels, but diet plus exercise substantially increased them.
Even if you already have heart disease, small increases in physical fitness can make a significant difference in cardiovascular risk. If you have heart problems or if you experience chest pain during a workout, talk to your doctor before you start an exercise regimen. You can minimize any risks of physical activity by starting gradually, avoiding overexertion, and seeking medical attention promptly if you have chest pains, leg cramps, undue shortness of breath, palpitations, or light-headedness. A doctor’s evaluation is important because such symptoms may suggest a disorder of the heart, lung, nervous system, or blood vessels.
How much should you exercise?
Given the wide range of health benefits associated with regular physical activity, the 2008 Physical Activity Guidelines for Americans recommend at least 150 minutes (2 hours and 30 minutes) a week of moderate-intensity physical activity, or 75 minutes (1 hour and 15 minutes) a week of vigorous-intensity activity. You can also do an equivalent combination of moderate and vigorous aerobic exercise.
Getting going with exercise
It’s best to check with your doctor before starting an exercise program. But it’s probably safe for you to start exercising if you can honestly answer “no” to all of the following questions:
- Has your doctor ever suggested that you have heart trouble?
- Do you frequently have pain in your heart and chest?
- Do you often feel faint or have spells of severe dizziness?
- Has your doctor ever said your blood pressure was too high?
- Has your doctor ever told you that you have a bone or joint problem, such as arthritis, that has been aggravated by exercise or might be made worse by it?
- Are you over 65 and not accustomed to vigorous exercise?
- Is there a good reason not mentioned here why you should not exercise?
If you answered “yes” to any of these questions, see your physician before exercising. He or she will take a medical history, conduct a physical examination, and — if you are over age 35 and sedentary — may suggest an ECG to look for signs of subtle coronary artery disease, abnormal heart size, or abnormal heart rhythms.