You may know exercise is good for the heart, but did you know that lack of exercise is one of the risk factors for developing heart disease? Several years ago, the American Heart Association added inactivity to its list of risk factors, which also includes family history, high blood pressure, high cholesterol, diabetes and obesity.

Below, the American Council on Exercise (ACE) and Club Industry magazine have listed 10 ways in which exercise helps prevent heart disease. To reap the numerous rewards of exercise, try to include at least 30 minutes of moderate physical activity, such as walking, on most days of the week. If you can't fit in a single 30-minute session, split up your activity into three 10-minute blocks spread throughout your day. And, of course, check with your doctor before starting a new exercise program.

THE TOP 10 WAYS EXERCISE CAN REDUCE
THE RISK OF HEART DISEASE

1. Cardiovascular exercise improves blood circulation, which may help reduce the risk of developing clots or blockages in the arteries.

2. Like the muscles of the body, the heart is a muscle, and regular exercise helps keep it toned and strong. As the heart becomes stronger, the heart rate lowers because fewer beats are required to pump the same amount of blood.

3. Exercise can help reduce or prevent high blood pressure in some people.

4. Research shows that exercise can raise HDL levels, the so-called "good" cholesterol, which has been linked to a lower risk of heart disease.

5. Exercise reduces the risk of diabetes, a risk factor for heart disease.

6. People who exercise are less likely to smoke. Several studies have confirmed that if you're a smoker and find it difficult to quit, exercise can still be beneficial. In fact, smokers who are active may have a lower risk of heart disease than non-smokers who are sedentary.

7. People who exercise tend to have healthier diets. Being active often compels people to make other positive lifestyle changes, such as eating less fat and more fiber. This benefits the heart.

8. Along with a healthy diet, exercise can aid in weight control. Weight problems such as obesity have been linked to heart disease. Burning calories regularly through exercise makes it easier to maintain a healthy weight.

9. Exercise has been proved to help manage stress, which can take its toll on the whole body - especially the heart. Furthermore, people who exercise tend to be less depressed and possess a more positive outlook.

10. Exercise strengthens muscles and improves mobility, making it easier to perform activities of daily living. The easier these activities are, the more active one is likely to be overall. In turn, increased activity reduces the risk of heart disease.