You've probably heard countless times how exercise is "good for you." But did you know that it can actually help you feel good, too? Getting the right amount of exercise can rev up your energy levels and even help improve your mood.

Rewards and Benefits

Experts recommend that teens get 60 minutes or more of moderate to vigorous physical activity each day. Here are some of the reasons:

• Exercise benefits every part of the body, including the mind. Exercising causes the body to produce endorphins, chemicals that can help a person to feel more peaceful and happy. Exercise can help some people sleep better. It can also help some people who have mild depression and low self-esteem. Plus, exercise can give people a real sense of accomplishment and pride at having achieved a certain goal — like beating an old time in the 100-meter dash.
• Exercising can help you look better. People who exercise burn more calories and look more toned than those who don't. In fact, exercise is one of the most important parts of keeping your body at a healthy weight.
• Exercise helps people lose weight and lower the risk of some diseases. Exercising to maintain a healthy weight decreases a person's risk of developing certain diseases, including type 2 diabetes and high blood pressure. These diseases, which used to be found mostly in adults, are becoming more common in teens.
• Exercise can help a person age well. This may not seem important now, but your body will thank you later. Women are especially prone to a condition called osteoporosis (a weakening of the bones) as they get older. Studies have found that weight-bearing exercise — like jumping, running, or brisk walking — can help girls (and guys!) keep their bones strong.

The three components to a well-balanced exercise routine are: aerobic exercise, strength training, and flexibility training.

Aerobic Exercise

Like other muscles, the heart enjoys a good workout. You can provide it with one in the form of aerobic exercise. Aerobic exercise is any type of exercise that gets the heart pumping and quickens your breathing. When you give your heart this kind of workout regularly, it will get stronger and more efficient in delivering oxygen (in the form of oxygen-carrying blood cells) to all parts of your body.

If you play team sports, you're probably meeting the recommendation for 60 minutes or more of moderate to vigorous activity on practice days. Some team sports that give you a great aerobic workout are swimming, basketball, soccer, lacrosse, hockey, and rowing.

But if you don't play team sports, don't worry — there are plenty of ways to get aerobic exercise on your own or with friends. These include biking, running, swimming, dancing, in-line skating, tennis, cross-country skiing, hiking, and walking quickly. In fact, the types of exercise that you do on your own are easier to continue when you leave high school and go on to work or college, making it easier to stay fit later in life as well.

Strength Training

The heart isn't the only muscle to benefit from regular exercise. Most of the other muscles in your body enjoy exercise, too. When you use your muscles and they become stronger, it allows you to be active for longer periods of time without getting worn out.

Strong muscles are also a plus because they actually help protect you when you exercise by supporting your joints and helping to prevent injuries. Muscle also burns more energy when a person's at rest than fat does, so building your muscles will help you burn more calories and maintain a healthy weight.

Different types of exercise strengthen different muscle groups, for example:

• For arms, try rowing or cross-country skiing. Pull-ups and push-ups, those old gym class standbys, are also good for building arm muscles.
• For strong legs, try running, biking, rowing, or skating. Squats and leg raises also work the legs.
• For shapely abs, you can't beat rowing, yoga or pilates, and crunches.

Flexibility Training

Strengthening the heart and other muscles isn't the only important goal of exercise. Exercise also helps the body stay flexible, meaning that your muscles and joints stretch and bend easily. People who are flexible can worry less about strained muscles and sprains.

Being flexible may also help improve a person's sports performance. Some activities, like dance or martial arts, obviously require great flexibility, but increased flexibility can also help people perform better at other sports, such as soccer or lacrosse.

Sports and activities that encourage flexibility are easy to find. Martial arts like karate also help a person stay flexible. Ballet, gymnastics, pilates, and yoga are other good choices. Stretching after your workout will also help you improve your flexibility.

What's Right for Me?

One of the biggest reasons people drop an exercise program is lack of interest: If what you're doing isn't fun, it's hard to keep it up. The good news is that there are tons of different sports and activities that you can try out to see which one inspires you.

When picking the right type of exercise, it can help to consider your workout personality. For example, do you like to work out alone and on your own schedule? If so, solo sports like biking or snowboarding may be for you. Or do you like the shared motivation and companionship that comes from being part of a team?

You also need to plan around practical considerations, such as whether your chosen activity is affordable and available to you. (Activities like horseback riding may be harder for people who live in cities, for example.) You'll also want to think about how much time you can set aside for your sport.

It's a good idea to talk to someone who understands the exercise, like a coach or fitness expert at a gym. He or she can get you started on a program that's right for you and your level of fitness.

Another thing to consider is whether any health conditions may affect how — and how much — you exercise. Doctors know that most people benefit from regular exercise, even those with disabilities or conditions like asthma. But if you have a health problem or other considerations (like being overweight or very out of shape), talk to your doctor before beginning an exercise plan. That way you can get information on which exercise programs are best and which to avoid.

Too Much of a Good Thing

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.

Exercising too much in an effort to burn calories and lose weight (also called compulsive exercise) 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.

Reviewed by: Mary L. Gavin, MD
Date reviewed: July 2012