All teens should get at least 60 minutes of exercise daily, according to current recommendations. Not only does exercise help you burn calories, but you'll also increase your cardiovascular endurance. And here's another benefit: Gaining muscle can help you burn more calories all day, even while you are sitting around. Muscle mass is metabolically active tissue, meaning it is the tissue that burns calories.
If you already get 60 minutes of exercise daily, you may need to add 30 more minutes. If you don't get 60 minutes a day, start today. If you haven't been exercising and are overweight, it's a good idea to check with your doctor before you start a vigorous exercise program.