Strength Training For Kids

(CBS)  When most of us think about strength training, images of Arnold Schwarzenegger come to mind. But there is a whole new group out there enjoying its benefits.

Dr. Mallika Marshall from WBZ-TV explained on The Saturday Early Show that kids are pushing, pulling and lifting their way to better health.

It wasn't long ago that strength training was discouraged in children under the age of 14. The fear was that it would hurt their young bodies and delay their growth. But new research out of Boston suggests pumping iron is not only safe for kids, it's beneficial.

"Instead of stunting bone growth, it is the best thing to stimulate bone growth and to add muscle to bone," says exercise researcher Dr. Wayne Prescott.

Kids in the study strength trained twice a week for eight weeks, and the results were impressive. They increased lean tissue by about two pounds, and that tissue is essential to keeping fit and fighting childhood obesity.

"In the old days, you would wrestle around and climb trees and things of that nature, but that doesn't happen too much anymore," says Dr. Prescott. "So a nice sensible, progressive, supervised strength training program provides that [exercise] in a very sound and beneficial way."

Fitness experts say most kids can start a strength training program as early as age seven. But they warn that it's important to use equipment that is designed for children.

Marshall says strength training for adults and children is very different. Adults often power-lift, which involves doing two or three repetitions of heavy weights. In children, experts encourage a higher number of repetitions with lighter weights.

The best way to observe whether children are over-exerting themselves is to see if they can do at least 15 repetitions of any exercise easily, she says. Lifting too much can damage growth plates, which are the areas of growing tissue near the end of the long bones in children and adolescents.

There are some strength training risks. Marshall says 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 Certified Strength and Conditioning Specialist degree (CSCS). Also make sure the teacher has worked with kids before. A class should have no more than 10 kids per instructor. In beginner classes, the teacher-student ratio should be even lower.

Marshall also says any child doing strength training should avoid improper technique, such as lifting a weight the wrong way or working out on a machine designed for adults, because improper technique can cause serious problems, such a muscle tears or growth plate damage.