If you’ve ever heard that weightlifting isn’t safe for kids under 12 because it stunts their growth, you’re not alone. This myth persists despite lacking any truth, according to the American Council on Exercise. Beyond improving muscle strength, increasing bone density and lowering cholesterol, working out with weights has an often overlooked benefit -- it gives overweight children who may struggle with other sports a chance to excel in an area of physical fitness. At the appropriate age, using weights is a great way for children to strength train.
Generally, a child can begin to work out with weights at the same time she is ready for organized sports. This means, she must be able to follow directions, understand proper form and adhere to safety procedures, including always warming up before and cooling down after. For most kids, this readiness occurs around 7 or 8 years old. The American Academy of Pediatrics Council on Sports Medicine and Fitness warns against weight training before this time because the balance and body control skills are not yet fully developed.
No matter his age, a child should start with light weights and focus on repetitions. However, more than age, the beginning weight will depend on the child’s strength ability. The repetition rule is the same for all children -- if a child can’t do eight reps with the weight, it's too heavy. After a child successfully performs 15 reps, he can progress to a weight 10 percent heavier.
A young child will not develop bigger muscles from working out with weights because the hormones responsible for increasing muscle size are not yet present. Using weights at this age helps a child develop muscle strength, felt through firmer muscles. Once the hormones are present during puberty, weightlifting helps the muscles grow in size. Although puberty begins sooner for some, and later for others, most girls begin puberty at 11 and mature at 14. Most boys begin at 12 and mature at 15 or 16.
Supervision and instruction from a qualified strength-training coach is imperative. Most injuries are the result of unsafe behavior on home equipment used without supervision, reports the American Academy of Pediatrics. The AAP adds that in settings with supervision and proper technique, weightlifting injury rates are lower than injury rates from other sports or from recess at school. Olympic lifts, power lifts and single repetition maximum effort are not safe for a child of any age.