Benefits of Exercise

Regular exercise makes the heart stronger and the lungs fitter, enabling the cardiovascular system to deliver more oxygen to the body with every heartbeat and increasing the maximum amount of oxygen that the body can take in and use. Exercise lowers blood pressure and reduces the levels of total and low density lipoprotein (LDL) cholesterol (the bad cholesterol), which in turn reduces the risk of heart attack, stroke, and coronary artery disease. Other conditions that are less likely to occur with regular exercise include colon cancer and some forms of diabetes.

Exercise makes muscles stronger, allowing people to perform tasks that they otherwise might not be able to do. Most everyday tasks require muscle strength and good range of motion in joints, and regular exercise can improve both.

Exercising stretches muscles and joints, which in turn can increase flexibility and help prevent injuries. Weight-bearing exercise strengthens bones and helps prevent osteoporosis. Exercise can improve function and reduce pain in people with osteoarthritis, although exercises that put undue stress on joints, such as running, may need to be avoided.

Exercise increases the body's level of endorphins. Endorphins are chemicals in the brain that reduce pain and induce a sense of well-being. Thus, exercise appears to help improve mood and energy levels and may even help alleviate depression. Exercise also helps boost self-esteem by improving a person's overall health and appearance.

Besides the ways in which exercise benefits people of any age, regular exercise helps older people remain independent by improving functional ability and by preventing falls and fractures. It can strengthen the muscles of even the frailest older person living in a nursing home. It tends to increase appetite, reduce constipation, and promote sleep.

The benefits of exercise diminish within months after a person stops exercising. Heart strength, muscle strength, and the level of high-density lipoprotein (HDL) cholesterol (the good cholesterol) decrease, whereas blood pressure and body fat increase. Even former athletes who stop exercising do not retain measurable long-term benefits. They have no greater capacity to perform physical activities and no fewer risk factors for heart attacks those who have never exercised, nor do they regain fitness any faster.

See the sidebar Athletic Heart Syndrome.