Aerobic fitness is related to health. In the United States, over 800,000 people die each year from coronary artery disease (CAD) which is the number one killer in the United States. The risk factors for CAD include: Inactivity, high cholesterol levels, smoking, overweight, high blood pressure, and diabetes. Numerous studies have shown that inactivity is the most important factor responsible for CAD. It is twice as important as high cholesterol levels, and four times more important than high blood pressure. Consequently, exercise reduces the risk of dying from a heart attack and it is an effective method of rehabilitation in people who have suffered from a heart attack.
