No, Lifting Weights Won't Stunt Your Kid's Growth

Every season, a parent pulls me aside with some version of the same worry: won't lifting weights stunt my kid's growth? It's one of the most common questions I get, and it almost always comes from a good place. A parent paying attention, who heard something somewhere, who wants to do right by their kid before signing them up for anything.

So let me answer it directly, because the science here is not actually murky. It just hasn't caught up to a myth that's been floating around for decades.

Will Lifting Weights Stunt a Child's Growth?

No. There is no credible evidence that properly supervised strength training stunts growth in children or adolescents. None.

The fear centers on the growth plates, the areas of developing cartilage near the ends of long bones where growth happens. The concern is that loading those bones could damage the plates and limit a kid's height. It sounds plausible, which is part of why the myth has lasted. But the research doesn't support it. The major organizations that have studied youth training, including the American Academy of Pediatrics and the National Strength and Conditioning Association, have reviewed the evidence carefully and landed in the same place: resistance training is safe and beneficial for kids when it's coached correctly. Done right, it builds stronger bones, not weaker ones.

The growth-plate injuries that do happen in young athletes overwhelmingly come from sports, from a bad landing on the basketball court or a collision on the field, not from a coached strength session.

Where the Myth Actually Came From

It's worth understanding why this idea took hold, because the origin tells you exactly what to avoid.

Decades ago, a handful of reports linked growth-plate injuries to weightlifting in young people. The problem wasn't strength training as a concept. It was the conditions. Those injuries came from kids attempting maximal lifts with no supervision, no instruction on technique, and loads far beyond what they could control. A 12-year-old trying to one-rep-max a barbell in a garage with nobody watching is a real risk. That has almost nothing to do with what structured youth strength training looks like.

The myth survived because it sounds responsible. Telling a kid to wait until they're older feels like the cautious choice. In reality, the cautious choice is teaching them to move well under light load early, with a coach watching, so they never end up as the unsupervised kid loading a bar they have no business touching.

So What Age Can Kids Actually Start?

Readiness matters more than a number on a birth certificate. The general guidance, and what I've found true in practice working with young athletes in the South County area, is that kids can begin structured strength work as young as seven or eight, provided they can follow instructions, stay focused for a short session, and respect the training environment.

At that age, "strength training" doesn't mean a loaded barbell. It means bodyweight movements, light implements, and learning to squat, hinge, push, and pull with clean technique. The early years are about building motor skills and a relationship with training, not chasing numbers. As a young athlete matures, demonstrates control, and shows they can handle progression responsibly, the load increases gradually. By the time they reach high school, an athlete who started early already moves better than most of their peers and is ready for real loading.

If your kid is asking to start, that interest is worth honoring. The answer is rarely "wait." It's "let's start the right way."

What Youth Strength Training Should Look Like

A good youth session looks more like a skill practice than a bodybuilding workout, and that's by design.

Technique comes before load, every time. We teach a young athlete to own the movement pattern with their bodyweight or a light dumbbell before anything heavier enters the picture. The reps stay submaximal, meaning we're never grinding out a max attempt or pushing a kid to failure on a heavy lift. The focus is on quality of movement, consistency, and gradual, intentional progression over months. Some days a session looks like a circuit of squats, push-ups, carries, and jumps. The athlete is building coordination, body awareness, and a foundation that will pay off for the rest of their athletic life.

What it does not look like is a scaled-down version of an adult powerlifting program or a college team's offseason block. Young athletes have school, sport practice, growth, and the rest of their lives pulling on their recovery. The program has to fit inside that reality, not bulldoze it. This is the same principle I've written about regarding [how often high school athletes should actually lift](/blog/how-often-should-high-school-athletes-lift-weights), and it applies even more to younger kids.

The Real Risk Isn't the Weight Room

Here's the part that surprises most parents. The weight room, done properly, is one of the safest places a young athlete spends their time, and it actively reduces their injury risk everywhere else.

The genuine threats to young athletes today are overuse and early sport specialization. Kids playing one sport year-round, with no offseason and no varied movement, accumulate repetitive stress on the same joints and tissues until something gives. That's where a large share of youth sports injuries come from, not from coached strength work. Structured strength training is part of the solution. The research on neuromuscular and resistance training in young athletes is consistent: it meaningfully lowers the rate of sports injuries, including the serious knee injuries that sideline kids for a year or more. A stronger, better-coordinated athlete absorbs force better, lands better, and breaks down less.

So the question isn't really whether strength training is safe for your kid. The honest question is whether you can afford to leave them weaker than they need to be in a sport that's going to demand a lot from their body.

How We Train Young Athletes at Output Performance

At Output Performance in Affton, we coach young athletes the way the research says they should be coached. Technique first, age-appropriate loading, progression that's earned, and a coach watching every rep. Parents are often surprised at how much of the early work is teaching kids to move, not loading them up. That's the point. We're building athletes for the long run, not impressing anyone in a single session.

If you're a parent in the St. Louis area wondering whether your young athlete is ready to start training the right way, learn more about our [team training program](/services/team-training) and let's talk about what a real foundation could look like for them.