Exercise is a great way to look and feel better, but if you're over 35 or have a history of medical problems, it's important to see a doctor first. Most doctors will perform a medical or fitness evaluation to assess your current health. Depending on the results of these tests, the doctor can help you plan an exercise program that's safe and enjoyable, and provides the desired results. Aerobic exercise in particular is a good way to burn calories, relieve stress, condition your heart and lungs, tone muscles, and increase stamina. Examples of aerobic exercise include swimming, jogging, bicycling, racquetball, and aerobic dance. Sports like these burn between five hundred and seven hundred calories an hour. They're most beneficial if done at least three times a week for 30 minutes. If you're out of shape, you may prefer to start out with less strenuous alternatives, like walking, tennis, or golf. While these activities won't burn as many calories, or provide the same degree of cardiovascular fitness, they can still be quite beneficial. Other ways to increase your daily activity are to take the stairs instead of the elevator; walk when doing errands; and take up a hobby, such as bowling, gardening, or dancing. For more information about which exercise is best for you, consult a health care provider.