At What Age Can a Child Work Out With Weights?

If you've ever heard that weight lifting 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 other, often overlooked benefits. It helps children develop a positive self-image, self-esteem and mental discipline. It also gives overweight children who may struggle with other sports a chance to excel in an area of physical fitness.

Generally, children can begin to work out with weights at the same time they are ready for organized sports. This means they are able to follow directions, understand proper form and adhere to safety procedures, including always warming up before and cooling down after a workout.

For most kids, this readiness occurs around 7 or 8 years old, according to KidsHealth from Nemours, a nonprofit children's health system. It's not advisable to use weights before this time because the balance and body control skills are not yet fully developed.

Read more: Is It Healthy for a 15-Year-Old to Lift Weights?

Before puberty, children will not develop bigger muscles from working out with weights because the hormones responsible for increasing muscle size are not yet present. Although puberty begins sooner for some, and later for others, most girls begin puberty at 11, according to the American Academy of Pediatrics. Most boys begin puberty a couple of years later than girls.

As such, the focus of weight training before puberty should be on mastering proper form and technique, not building big muscles. Using weights at this age helps a child develop muscle strength, felt through firmer muscles.

Once the hormones are present during puberty, weight lifting helps the muscles grow in size. Note that children may also experience a temporary decline in balance and body control following a growth spurt. Trainers and coaches can work with children to adjust to their new body size while gaining strength with weight training.

Read more: The Average Weight Bench Press for a 15-Year-Old

As children begin a weight lifting routine, they should start with light weights and focus on high 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.

Children should avoid lifting heavy weights as their growth plates mature. These growth plates, located inside the ends of teenagers' bones, are more delicate than the surrounding bones, muscles, tendons or ligaments. They are also weaker during periods of rapid growth.

According to Stanford Children's Health, too much weight may stress or damage the joints and ligaments and separate a teen's growth plates. To avoid injury, keep the focus on weight training and muscle strengthening rather than heavy lifting.

No matter what age they start working out, make sure children have adequate guidance to prevent injuries and get the most out of their training. Supervision and instruction from a qualified strength-training coach is imperative. Note that Olympic lifts, power lifts and single-repetition maximum effort are not safe for a child of any age.

Without that supervision, children may practice unsafe behavior on home equipment. They might use weights that are too heavy for them or even drop weights on themselves while trying to work out.

It's also important to monitor children for any signs of overuse injuries. An overuse injury results from damage caused to a bone, muscle, ligament or tendon caused by repetitive stress.

When children don't have adequate time for muscles to heal from a weight-training session, injuries are more likely. To prevent overuse, children should aim to strength train about three times a week, according to the Physical Activity Guidelines for Americans.