Being fit means you're in good shape, you have energy, you're active, and you don't get tired easily during the day. Most people who are fit also feel pretty good about themselves.

Any type of regular, physical activity can improve your fitness and your health—even walking, climbing up a flight of stairs, or mowing the lawn. The most important thing is that you keep moving!

Feel better, look better

There are a lot of benefits to being physically active. It can help

• Keep you at a healthy weight. This doesn't necessarily mean being thin. Everybody's ideal weight is different—it depends on your height and body size. Ask your pediatrician what the right weight is for you.
• Prevent heart disease. Heart disease is the leading cause of death in the United States. Research has shown that the risk factors for heart disease start during childhood. A lack of physical activity is one of the major risk factors of heart disease.
• Strengthen your bones. Regular exercise keeps bones healthy and can help prevent a bone disease called osteoporosis. This disease is common in older people and causes bones to break easily.
• Reduce stress. We all have stress, but learning to cope with it is an important way to stay healthy. Many things can cause stress like problems with parents or friends or the pressures of school. Major things like moving to a new home or breaking up with someone can also cause stress. Exercise can help you relax and helps your body handle stress.

Total fitness

To be fit, you might find it helpful to work on all aspects of fitness, including the following:

Aerobic endurance—This is how well your heart, lungs, and blood vessels provide oxygen and nutrients throughout your body. When you exercise, you breathe harder and your heart beats faster. This helps your body get the oxygen it needs. If you are not fit, your heart and lungs have to work extra hard, even to do everyday things like walking up the stairs.

Body fat—How much you weigh is not the only way to tell if you are overweight. It's actually determined by your body mass index (BMI), which includes your weight and height and gives an idea of how much of your body weight comes from fat. People who are overweight have more body fat in relation to the amount of bone and muscle in their bodies. Eating too much and not exercising enough can cause you to have too much body fat. Your risk of health problems like diabetes, cancer, high blood pressure, knee and back pain, and heart attacks is increased when you're overweight.

Muscle strength and endurance—This is the amount of work and the amount of time that your muscles are able to do a certain activity before they get tired. The more fit you are, the longer you are able to play a sport, work out, or do other activities before you have to stop.

Flexibility—This is how well you can move and stretch your joints, ligaments, and muscles through a full range of motion. For example, people with good flexibility can bend over and touch the floor easily. Poor flexibility may increase the risk of getting hurt during athletic and everyday activities.

What can I do to become more fit?

Just do it! Make the commitment and stick to it. Exercise should be a regular part of your day, like brushing your teeth, eating, and sleeping. It can be in gym class, joining a sports team, or working out on your own.

Stay positive and have fun. A good mental attitude is important. Find an activity that you think is fun. You are more likely to keep with it if you choose something you like. A lot of people find it's more fun to exercise with someone else, so see if you can find a friend or family member to be active with you.

Take it one step at a time. Small changes can add up to better fitness. For example, walk or ride your bike to school or to a friend's house instead of getting a ride. Get on or off the bus several blocks away and walk the rest of the way. Use the stairs instead of taking the elevator or escalator.

Get your heart pumping. Whatever you choose, make sure it includes aerobic activity that makes you breathe harder and increases your heart rate. This is the best type of exercise because it increases your fitness level and makes your heart and lungs work better. It also burns off body fat. Examples of aerobic activities are basketball, running, or swimming. (See the Fitness Activity Chart at the end of this brochure for more ideas.)

Don't forget to warm up with some easy exercises or mild stretching before you do any physical activity. This warms your muscles up and may help protect against injury. Stretching makes your muscles and joints more flexible too. It is also important to stretch out after you exercise to cool down your muscles.

How often should I exercise?

Your goal should be to do some type of exercise every day. It is best to do some kind of aerobic activity without stopping for at least 20 to 30 minutes each time. Do the activity as often as possible, but don't exercise to the point of pain.

Like all things, exercise can be overdone. You may be exercising too much if

• Your weight falls below what is normal for your age, height, and build.
• It starts to get in the way of school and your other activities.
• You start to have bone, joint, or muscle pain that affects your daily activities.
• You are a girl and your periods become irregular, sporadic, or stop completely.

If you notice any of these signs, talk with your parents or pediatrician before health problems occur.

Is it safe to train with weights?

Strength training, also called “weight training” or “resistance training,” is an activity in which you use free weights, weight machines, resistance bands, or even your own weight to increase muscle strength and muscle endurance. The goal is not to bulk up, but to build strength and coordination. Do not focus on how much weight you are lifting, but rather on doing the exercises slowly and safely. When done correctly, this can be a great way to increase your strength and fitness.

Start with light weights and use smooth, controlled motions. Increase the number of times you lift the weight (repetitions) gradually. Avoid strength training more than 3 times per week and make sure you have a day of rest in between each workout. Too much weight training can be harmful and there are no extra benefits to strength training more often.

Safety measures should be taken during strength training. Most strength training injuries happen when exercises are not done correctly, when too much weight is lifted, or when there is no adult supervision.

Weight training isn't the same as weight lifting, power lifting, and body building. Avoid these activities until your body has reached full adult development (usually after the age of 18) because these sports can result in serious injury. Ask your pediatrician when it is a good time for you to start.

A healthy lifestyle

In addition to exercise, making just a few other changes in your life can help keep you healthy, such as

• Watch less TV or spend less time playing computer or video games. (Use this time to exercise instead!) Or exercise while watching TV (for example, sit on the floor and do sit-ups and stretches; use hand weights; or use a stationary bike, treadmill, or stair climber).
• Eat 3 healthy meals a day, including at least 4 servings of fruits, 5 servings of vegetables, and 4 servings of dairy products.
• Make sure you drink plenty of fluids before, during, and after any exercise (water is best but flavored sports drinks can be used if they do not contain a lot of sugar). This will help replace what you lose when you sweat.
• Stop drinking or drink fewer regular soft drinks.
• Eat less junk food and fast food. (They're often full of fat, cholesterol, salt, and sugar.)
• Get 9 to 10 hours of sleep every night.
• Don't smoke cigarettes, drink alcohol, or do drugs.

Fitness Activity Chart

Modified from Bar-Or O. Pediatric Sports Medicine for the Practitioner. New York, NY: Springer-Verlag; 1983: 349–350

Ferguson JM. Habits, Not Diets. Palo Alto, CA: Bull Publishing Co; 1988

View Large

The persons whose photographs are depicted in this publication are professional models. They have no relation to the issues discussed. Any characters they are portraying are fictional.

Copyright © 2006