Health experts have long promoted the idea of kids playing sports, swimming, hiking, biking and just plain running around. But when it comes to another form of exercise, strength training, the jury has been out.
Specialists once cautioned that strength training was a no-no before puberty, when the growth plates – the areas of tissue near the ends of each long bone that allow the bone to grow – close. Growth-plate injuries can impact the growth of a limb. But studies have shown that weight-training injuries are rare in kids. “In fact, it’s far less frequent than with soccer or any other contact sport,” says Kaiser Permanente family and sports medicine specialist Thad Woodward, M.D.
And it has many benefits. These include increased strength, coordination and bone density and a proven reduction in sports injuries, including ACL injuries. Kids who strength train may also experience less back pain. And there are emotional benefits as well – especially for tweens and teens. “It improves your mental outlook,” says Woodward. “A lot of times at this age, they’re undergoing a lot of emotional stress through peer pressure, and it gives them the confidence to deal with that.”
To be clear, we’re not talking about bodybuilding – which emphasizes improving appearance. Strength training, according to Woodward, focuses on building strength with “anything that gives your muscles resistance as you’re doing exercise.” This could be rubber bands, a machine or even your own body weight.
Woodward, whose 10-year-old daughter plays basketball on a co-ed team, says most kids can start strength training around age 9, but be sure your child is mature enough to follow directions and check in with your pediatrician first.
You could pick up some resistance bands or begin with body-weight exercises such as sit-ups, pushups and planking. Getting help from a professional trainer who has experience with children is a good idea, and your own trainer or your child’s pediatrician, school or sports coach can likely refer you to one.
Learn the trainer’s suggested exercises along with your child (Woodward suggests making videos with your phone), and continue to supervise your child’s workouts at home. “Make sure that you are familiar enough with the exercises they’re doing to spot if they’re doing it improperly,” Woodward says.
Kids should strength train no more than three days per week. For each exercise, they should do just two or three sets of about 12-15 repetitions that they can easily complete. “If they’re straining and they’re really pushing and they’re cheating by putting other muscle groups in there, that’s not what we’re doing,” says Woodward.
Most injuries in kids happen when they are training with excessive weight and/or improper form. It’s OK for kids to be a tiny bit sore after a workout, but they shouldn’t be limping or flinching when they use their arms.
If your child is training correctly, you’ll see strength gains in as little as six or eight weeks – but there won’t be any bulking up. “They’re not really building muscle mass,” says Woodward. “It’s more that they’re coordinating the nerves and the muscles to work together for a certain activity. You’ll see them gain strength, but they’re not getting any bigger.”