to break. But once you make exercise a consistent part of your life, you’ll miss it when you don’t do it—you’ll miss the feeling of doing something healthy for yourself, the occasional soreness of your muscles that reminds you that you’re getting healthier, and the overall sense of well-being that exercise brings on.

Exercise’s impact on heart health is amazing. Research has shown that even moderate exercise can substantially reduce the incidence of coronary events. Aerobic exercise reduces cardiac risk by lowering triglycerides and raising HDL cholesterol levels; by reducing blood pressure, body fat, blood sugar, and mental stress; and by moderating the blood’s propensity to clot.

Exercise also improves the heart’s pumping ability, which greatly enhances the body’s functional capacity and stamina. And it’s never too late to start. Healthy people who begin exercising after age forty-five can reduce their death rate by 23 percent over the next twenty years or so.

And even patients who’ve already had heart attacks can use medically supervised aerobic exercise to reduce their risk for another heart attack by up to 25 percent. Sedentary living, on the other hand, is the fifth major cardiac risk factor. Because it increases the risk for coronary artery disease by almost two times, a lack of exercise is nearly as dangerous as smoking, abnormal cholesterol levels, or hypertension.

What kind of exercise is best? If you’re usually sedentary, the most important thing is to incorporate almost any kind of physical activity into your daily life. Gardening, housework, and even taking the stairs count as light exercise. More regular, sustained exercise is even better.

Your goal is to eventually incorporate the three main types of exercise into your week: aerobic exercise, strength training, and stretching. Aerobic exercise, which employs large muscle groups in a rhythmic, repetitive fashion for prolonged periods of time, has long been considered the best type of exercise for the heart.

Examples include brisk walking, jogging and running, biking, swimming, aerobic dance, rowing, cross-country skiing, and brisk singles racket sports. All patients with heart disease should discuss any exercise program with their doctor before they begin.

Along with personal advice, he or she will tell you to not do any activity that causes chest pain (angina) or that exceeds the activity threshold documented on your stress test. Regular exercise does raise your risk for minor injuries, such as shin splints or sprains and strains.

But if you talk to your doctor before you start a program, choose a low-impact activity, take it slowly at first, and very gradually increase the intensity of your program, the benefits—lower total cholesterol, lower triglycerides, higher HDL, lower blood pressure, better control of blood sugar, a stronger heart that pumps blood more efficiently, even a better mood—far outweigh the risks.

An exercise program doesn’t just happen on its own. It takes thought and perseverance to develop a routine that’s tailored to your needs. Your first priority should be finding an activity and a schedule that you can stick with over the long haul. To give yourself the best chance for success, start out gradually, set realistic goals, and reward yourself for accomplishments along the way.

In the past, walking may have had the unfair reputation of not being “real” exercise. After all, most people do it every day without a second thought. But times have changed, and walking has gained new respect. Before you take your first steps, follow these guidelines to plan your program:

• Find a safe place to walk. Options include quiet streets, trails in parks, athletic tracks at local schools, or a shopping mall.

• Invest in a good pair of shoes. Shoes for walking should have thick, flexible soles that cushion your feet and elevate your heel a half to three-quarters of an inch above the sole. The upper portion of the shoe should be constructed of “breathable” materials such as nylon mesh or leather.

• Consider choosing a partner or a group to walk with. Having company helps some people stay motivated. Depending on where and when you walk, it can also ensure your safety. However, if you use your exercise time as an opportunity for reflection, solitude may be more appealing.

• Wear clothes appropriate to the season. Wear lighter clothes than you’d need if you were standing still; you’ll warm up as you exercise. Dress in layers so you can peel off garments if you get hot.

• Stretch before you walk.

• Warm up and cool down. Include five-minute warm-up and cooldown segments as part of your total walking time.

• Practice good walking technique.

• Create a walking program that works for you.