Weight-Bearing Exercise for Kids

Strength training was once a workout for adults only, but more and more youngsters are taking it up. But is it safe?

One teenager hopes strength training will give her the competitive edge to become a professional soccer player.

Alex Singer says pumping iron isn't just for body builders. At 13 years old, the aspiring soccer star already swears by it.

"I feel a lot stronger and feel that on the field I can just go a lot longer than I used to," says Singer.

Lifting weights is only one part of Alex's strength-training routine. At her twice-weekly visits to a fitness center, she does a series of exercises that increase her ability to resist force. Each one is designed to prepare her for the rigors of competition.

"If it is done supervised and they are taught correctly by the right professional, then they are more than likely not to be injured," says physical therapist Vincent Sullivan.

And according to her mom, Alex isn't just toning her body: She's also building her confidence.

"She gets onto the field and she feels like she is the best and she knows she can handle whatever comes her way," says Laurie Singer Matthias.

To explain more about strength training in children and teens, Dr. Jordan Metzl. CBS News health contributor and sports medicine specialist, talked with the Saturday Early Show.

Is strength training safe for children?

Yes, it is very safe. Strength training if done properly does not damage growth plates or stunt growth in children--as was previously thought. However, it is very important that children follow nutritional guidelines, which include getting enough calcium.

How is strength training different in children compared to adults?

It is very different. Adults often power-lift, which is doing two or three repetitions of heavy weights. In children we encourage a higher amount of repetitions with less heavy weights.

What's the earliest a child could begin a strength-training program?

We see children as young as 6 in strength-training programs, which is about the same age many kids begin playing competitive sports, such as baseball and soccer. And research has shown that kids who begin strength-training programs have healthier hearts, stronger bones, and lower risks of developing diseases as adults. It can also helps reduce body fat.

What is a good workout routine for someone like 13-year-old Alex?

For someone such as Alex who plays soccer, I'd encourage her to do squats, hamstring curls, sit-ups, pushups, and ankle strengthening. It is important to cover all the major muscle groups. Now if your child plays football, for instance, you need to ask a trainer at the gym which exercises would be best.

How does a child know if he or she is lifting too much weight?

The best way to tell if a kid is lifting too much is if he or she can't do at least 15 repetitions of any exercise easily. Lifting too muccan damage growth plates.

Now you say there are some risks involved with strength training in children. Let's go through a few:

• Improper supervision: It is very important that your child get into a program run by a person who is qualified to train kids. Parents should ask if the instructor has a C-S-C-S degree. Also make sure the teacher has worked with kids before. A class should have no more than ten kids per instructor. In beginner classes, the teacher-student ratio should be even lower.
• Improper technique: Improper technique such as lifting a weight the wrong way or working out on a machine designed for adults can cause serious problems such a muscle tear or growth plate damage.
• Injury: Children are at a much higher risk of soft-tissue injury. Soft tissue is anything that is not bone. Growth plates are also an area where we see a lot of injuries. The best way to prevent injuries is to make sure a child is not lifting too much, ad it is important that children rest between exercises.