Exercise

The performance of any physical activity that improves health or that is used for recreation or for the correction of physical injury or deformity (see physiotherapy). Different types of exercise have different effects on the body. During aerobic exercise, such as jogging or swimming, the heart and lungs work faster and more efficiently to supply the muscles’ increased demand for oxygen; regular aerobic exercise improves the condition of both the cardiovascular and respiratory systems. Exercises such as weight training increase muscle strength and endurance. Activities such as yoga and pilates improve flexibility. Regular aerobic exercise usually leads to a reduction in blood pressure. It also results in an increased amount of highdensity lipoprotein ( HDL) in the blood, which is thought to help protect against atherosclerosis and myocardial infarction. Exercise can relieve the symptoms of peripheral vascular disease and of some psychological disorders, particularly depression. Regular weightbearing exercise, such as running, increases the density of, and thereby strengthens, the bones. The bone disease osteoporosis is less common in people who have exercised throughout their adult lives. However, vigorous exercise may cause injury and increase the risk of a heart attack in people who are out of condition. Professional sportsmen such as footballers have an increased risk of osteoarthritis in later life because of repeated minor damage to the joints.