STEVE INSKEEP, host:
Now, this fall, many kids playing sports are likely to suffer injuries. It's typical. One way to improve fitness and avoid injuries is weight training. That's right, weight training for kids. NPR's Patti Neighmond reports.
PATTI NEIGHMOND: Forget the image of the muscle-bound man or woman straining and sweating under a metal barbell with 40, 50 or even hundreds of pounds of weight on either side.
Mr. BROCK CHRISTOPHER (Sports Trainer, Velocity Sports Performance): Stand up nice and tall. Good. Hold that ball out. Twenty seconds.
NEIGHMOND: Jared Guerrero is 7 years old. With sturdy legs planted firmly on the floor, Jared's arms are straight out in front of his very determined-looking face. He holds a ball that looks sort of like a soccer ball, only this ball weighs 4 pounds.
Mr. CHRISTOPHER: Hold it above the head. Good. A little longer on this one. Pull that belly button to the spine.
NEIGHMOND: At Velocity Sports Performance in West Los Angeles, sports trainer Brock Christopher takes Jared through his paces: sprints and dashes, push-ups, sit-ups, squats and also weights.
Mr. CHRISTOPHER: Ready to bring the ball up?
Mr. JARED GUERRERO: Huh.
Mr. CHRISTOPHER: Ready and go and touch. One…
NEIGHMOND: This is pretty much the 7-year-old version of weightlifting. No metal bar or hundred-pound plates. The rubber ball Jared works with is called a medicine ball. They became popular 100 years ago for fitness work and rehab with the elderly. Trainer Brock Christopher.
Mr. CHRISTOPHER: The whole joy of a medicine ball is we can do 10 million different things with it.
NEIGHMOND: Years ago, weightlifting got a bad rap, says pediatric exercise researcher Avery Faigenbaum, who teaches exercise science at the College of New Jersey. Kids were doing bodybuilding in home basements, he says, lifting weights and hurting themselves either because the weights were too heavy or they dropped them. At the time, concerns were also raised about whether weight-bearing exercise was good for growing kids.
Faigenbaum says weightlifting with barbells can be safe for kids, but they have to be very closely supervised. Medicine balls are simpler, he says. They're less expensive and safer. Even if kids drop them, they're unlikely to hurt themselves. Faigenbaum adds that today's research shows weightlifting can even help build strong bones.
Professor AVERY FAIGENBAUM (Exercise Science, College of New Jersey): Weight-bearing physical activity is absolutely essential for building bone. And some people say the years of childhood and early adolescence, maybe under age 14 or so, are the ideal times to build bone. And if you miss out on this window of opportunity, you may never get it back.
NEIGHMOND: During exercise with a medicine ball, for example, the muscles pull on the bone during every push and pull. In response to that stimulus, bone-building cells migrate to the bone surface and actually start making new bone.
Faigenbaum says Olympic weightlifters have levels of bone mineral density well above their non-weightlifting counterparts. Even simple, day-to-day exercises, he says, can build bone.
Prof. FAIGENBAUM: When you perform hopscotch or jumping jacks, every hop and every skip and every jump, the bone bends just a little bit, and that bend stimulates growth. And over time, that's exactly what we want.
NEIGHMOND: And for overweight kids, resistance training can reduce the amount of actual fat by increasing the amount of muscle. Most important, though, says Faigenbaum, routine physical activity early on can prepare kids for a lifetime of exercise, with all its cardiovascular and disease-prevention benefits.
One footnote, however: Faigenbaum says exercise has to be made fun for kids, something sports trainer Brock Christopher knows well.
Mr. CHRISTOPHER: We also test them on state capitals. And watch this. See, this is how smart he is. Florida.
Mr. JARED GUERRERO: Tallahassee.
Mr. CHRISTOPHER: Connecticut.
Mr. GUERRERO: Hartford.
Mr. CHRISTOPHER: Maine.
Mr. GUERRERO: Augusta.
Mr. CHRISTOPHER: My home state, Idaho.
Mr. GUERRERO: Boise.
Mr. CHRISTOPHER: See? Unbelievable.
NEIGHMOND: And now, back to push-ups.
Patti Neighmond, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.