the national health and examination survey (nhanes i) showed that people who engage in limited recreational activity were more likely to gain weight than more active people. other studies have shown that people who engage in regular strenuous activity gain less weight than sedentary people. physical activity and exercise help burn calories. the amount of calories burned depends on the type duration and intensity of the activity. it also depends on the weight of the person. a 200-pound person will burn more calories running 1 mile than a 120-pound person because the work of carrying those extra 80 pounds must be factored in. but exercise as a treatment for obesity is most effective when combined with a diet and weight-loss program. exercise alone without dietary changes will have a limited effect on weight because one has to exercise a lot to simply lose one pound. however regular exercise is an important part of a healthy lifestyle to maintain a healthy weight for the long term. another advantage of regular exercise as part of a weight-loss program is a greater loss of body fat versus lean muscle compared to those who diet alone. other benefits of exercise include: improved blood sugar control and increased insulin sensitivity (decreased insulin resistance) reduced triglyceride levels and increased "good" hdl cholesterol levels lowered blood pressure a reduction in abdominal fat reduced risk of heart disease. remember these health benefits can occur independently (with or without) achieving weight loss. before starting an exercise program you should talk to your doctor about the type and intensity of the exercise program. general exercise recommendations: 20-30 minutes of moderate exercise 5 to 7 days a week preferably daily. types of exercise include walking stationary bicycling walking or jogging on a treadmill stair climbing machines jogging and swimming. exercise can be broken up into smaller 10-minute sessions. start slowly and progress gradually to avoid injury excessive soreness or fatigue. over time build up to 30 to 60 minutes of moderate to vigorous exercise every day. people are never too old to start exercising. even frail elderly individuals (ages 70-90 years) can improve their strength and balance. exercise precautions: the following people should consult a doctor before vigorous exercise: men over age 40 or women over age 50. individuals with heart or lung disease asthma arthritis or osteoporosis. individuals who experience chest pressure or pain with exertion or who develop fatigue or shortness of breath easily. individuals with conditions or lifestyle factors that increase their risk of developing coronary heart disease such as high blood pressure diabetes cigarette smoking high blood cholesterol or having family members with early onset heart attacks and coronary heart disease. a patient who is obese
what is the role of physical activity and exercise in obesity?