"I don't want to go to school!"

"But you have P.E. today."

"I hate P.E."

Have you ever had this conversation? Some kids don't like physical education class. "I'm uncoordinated," they say. Or, "the other kids never pick me for the team. I'm always last."

It does seem as if some kids are natural athletes, while others aren't. Sometimes, playing competitive sports like soccer or softball can show off those differences. And that's not much fun if you haven't gotten the hang of kicking a ball and running at the same time, or swinging a bat well enough to hit a ball over an infielder. That's when playing a competitive sport can be stressful.

The American Alliance for Health, Physical Education, Recreation and Dance has a plan to help kids who may not do so well in competitive situations. "Physical Best," a noncompetitive physical education program used all over the country, is designed for kids ages 5 to 18.

Instead of teaching you how to win, the program explains how to make good, healthy decisions about your body and how to keep in shape. Through Physical Best, you can learn how to keep your heart healthy. Keeping your heart healthy is one of the best reasons for taking part in gym class.

You might think that heart disease is an illness that only strikes old people, but the seeds of the disease are planted in childhood. According to "The Beat Goes On," a kids' book published by the alliance, 4 percent of kids in elementary schools have higher blood pressure than they should. Nearly 20 percent weigh too much for their own good. Almost 50 percent of elementary school students have tried smoking. These three factors all contribute to heart disease.

So what should you do? Eat well, don't smoke and exercise! Doctors say the best sport is the one you enjoy most. Fitness experts advise you to mix activities to develop strong hearts and lungs, as well as strong and flexible muscles. If you spend a lot of time playing a non-aerobic sport like volleyball, for example, then you should also get some aerobic exercise by bicycling, swimming or running. Aerobic exercise makes the heart pump fast and strong. Exercise not only helps build healthy bodies, it also makes you feel good about yourself and develop the lifelong habit of doing something physical.

Experts say that most children under age 6 usually don't have the skills needed for organized sports. For them, the best exercise is active play. By about 7, most kids have developed the motor skills they need for organized sports, but they still have a short attention span. They shouldn't be forced to play organized games for longer than they want to.

On the other hand, organized sports do teach some very important things. Being on a team gives you a sense of belonging to something. Sports can develop discipline, too. But let's get back to the reluctant athlete at the beginning of this column. You remember -- the kid who doesn't want to go to school because he hates P.E.

"Wait a minute," his dad says. "Let's think of some reasons why P.E. is important." Together, they came up with this list:

Exercise is good for your heart.

Exercise strengthens bones and muscles.

Exercise keeps weight under control.

Exercise helps your body fight off sicknesses like colds and the flu.

Playing sports helps you learn how to get along with other people.

Achieving an exercise goal -- like running a mile -- makes you feel good about yourself.

Exercise can help cheer you up when you're feeling down.

P.E. gets you out of your classroom and into the air and light, and there aren't any tests!

"By the way," the reluctant athlete's dad says. "Don't you have a softball game against the other fourth grade class today?"

"Yeah."

"Well, I think it's great when your team wins. But it's more important to me that you're getting exercise that will make you a strong and healthy person."

"Oh, okay . . ." his son says. "I guess I'll go to school after all."Tips for Parents

Getting the reluctant child out onto a field can be tough. Even tougher can be getting the competitive, obsessed young athlete to take it easy. The American Academy of Pediatrics cautions that children and adolescents should avoid weight lifting, power lifting and body building until they are physically mature -- about age 15 in both sexes, although individuals vary from this norm. Last month, the group released a statement saying that some children and many adolescents use weights to increase strength or enlarge muscles and a smaller number compete in weight lifting, power lifting and body building events. "Over 600 teenagers are registered with the U.S. Weight Lifting Federation and more than 3,000 with the U.S. Power Lifting Federation," the academy's statement said. "Limited data available indicate that these sports have a significant injury risk."

The American Alliance for Health, Physical Education, Recreation and Dance publishes materials for parents and kids. For more information, write to Physical Best, AAHPERD, 1900 Association Dr., Reston, Va. 22091-9989.

Catherine O'Neill is a freelance children's writer.