As with all good things, it's possible to overdo exercise. Although exercising is a great way to maintain a healthy weight, exercising too much to lose weight isn't healthy. The body needs enough calories to function properly. This is especially true for teens, who are still growing.
Compulsive exercise, exercising too much in an effort to burn calories and lose weight, can be a sign of an eating disorder. If you ever get the feeling that your exercise is in charge of you rather than the other way around, talk with your doctor, a parent, or another adult you trust.
It's also possible to overtrain — something high school athletes need to watch out for. If you participate in one sport, experts recommend that you limit that activity to a maximum of 5 days a week, with at least 2–3 months off per year. You can still train more than that as long as it's cross-training in a different sport (such as swimming or biking if you play football).
Participating in more than one activity or sport can help athletes use different skills and avoid injury. Also, never exercise through pain. And, if you have an injury, make sure you give yourself enough time to heal. Your body — and your performance — will thank you.
Considering the benefits to the heart, muscles, joints, and mind, it's easy to see why exercise is wise. And the great thing about exercise is that it's never too late to start. Even small things can count as exercise when you're starting out — like taking a short bike ride, walking the dog, or raking leaves.
If you're already getting regular exercise now, try to keep it up after you graduate from high school. Staying fit is often one of the biggest challenges for people as they get busy with college and careers.