Does Lifting Weights Stunt Growth? What the Research Actually Shows

No. There is no credible evidence that supervised, age-appropriate resistance training stunts a child's growth or damages healthy growth plates. A review of the research on physical activity and the epiphyseal growth plates found no link between structured strength training and reduced adult height (PMC). The American Academy of Pediatrics has held this position for well over a decade: properly supervised resistance training is safe and beneficial for children and adolescents.

The myth persists anyway. Here is where it came from, and what actually does put a growing bone at risk.

None of this means every gym or program is automatically safe. It means the growth-plate fear specifically, the idea that lifting itself damages a growing bone, is not supported by the evidence. The real safety questions are about supervision and technique, covered below.

Growth plates, the epiphyseal plates near the ends of long bones, are real, and they are softer than surrounding bone tissue until a child finishes growing. That biological fact got flattened, over decades of gym-class folklore, into the idea that lifting weights near a growth plate injures it. The two ideas are related but not the same.

Growth plate injuries are common in active kids. They account for a meaningful share of childhood fractures, most often in athletes ages 10 to 16 (physeal injuries in youth sports, PMC). But the leading causes are acute trauma and repetitive overuse from contact sports, running, pivoting, jumping, and unsupervised training, not properly coached resistance training (PMC).

Early caution around youth strength training also dates back to a handful of case reports and small, poorly controlled studies from decades ago, before better-designed research existed. Those early warnings hardened into conventional wisdom well before the evidence caught up.

Research on youth sports injuries points to a consistent, short list of actual risk factors, and supervised resistance training is not one of them:

• Unsupervised maximal lifts, where a young athlete attempts a heavy single rep without a coach correcting form
• Poor technique under load, loading a movement pattern the athlete has not yet learned to control
• Repetitive overuse without recovery, the same stress, sport-specific or gym-based, applied without enough rest between sessions
• Contact and collision, since the bulk of physeal injuries in youth sports come from contact sports and acute trauma, not the weight room (PMC)

None of these are arguments against strength training. They are arguments for supervised, technique-first programming, which is exactly what the age-by-age guidance from the AAP and NSCA already recommends. The same supervision principle applies whether the activity is a squat, a sprint, or a hockey drill.

Ontario hockey parents often worry more about the weight room than about the sport their child already plays every day, but the data points the other way. Growth plate and other injuries in youth sports concentrate in contact and collision activity, along with running, pivoting, and jumping-heavy movement, not supervised strength training (PMC). Hockey involves all of those movement patterns, plus body contact once checking is introduced.

A well-run strength program does not add to that risk. Done right, it can reduce it, by building the tissue capacity, coordination, and body control that help an athlete absorb contact and awkward landings.

Reviews of youth resistance training research consistently find the opposite of the growth-plate fear: supervised, age-appropriate programs are linked to improved bone mineral density during childhood and adolescence, when combined with adequate nutrition, not reduced growth (NSCA position statement). The review of physical activity and epiphyseal growth plates found no evidence that resistance exercise itself damages healthy growth plates when technique and load are appropriate for the athlete (PMC).

Boys are also more likely than girls to suffer growth plate injuries overall, and children carrying excess body weight face added stress on bones during any high-impact activity, not just lifting (PMC). Body weight and mechanics matter more than whether a barbell is involved.

This tracks with a broader pattern in bone research: mechanical loading, applied progressively, is one of the main stimuli that helps developing bone build density. A growing skeleton generally responds to appropriate load by adapting and strengthening, not by stalling out. None of this means training is risk-free, no physical activity is. It means the specific fear of stunted growth is not what the evidence shows.

Part of it is outdated caution from decades ago, before enough long-term data existed. Part of it is a reasonable-sounding but incorrect mental shortcut: growth plates sit near joints, joints move under load, so load must be risky. The research does not support that leap once supervision and technique are accounted for.

Fear also travels faster than nuance. A story about a teenager injured lifting unsupervised in a garage gym spreads further than a study showing no effect from a well-coached program, even though the two situations are not comparable.

For parents, the practical test is whether a specific program teaches technique before adding load. Our age-by-age guide to youth strength training covers what that looks like from age 6 through the teen years.

A short conversation with a coach or program director usually reveals whether growth-plate safety is being taken seriously in practice, not just in a waiver:

• How do you progress a young athlete from bodyweight to loaded movements?
• What is your ratio of coaches to athletes during a strength session?
• Do you test 1-rep maxes with kids, and if so, at what age?
• How do you handle an athlete who cannot yet control a movement pattern?

A program with clear answers to these questions is following the same supervision-first approach the AAP and NSCA recommend. Testing trends, not just a coach's word, can also confirm a program is working; see our guide to what off-ice testing actually measures. If your family is also weighing training against an upcoming Ontario hockey tryout season, the physical prep principles are the same: technique and consistency beat maxing out.

The growth-plate fear does not hold up against the research. What does carry real risk is unsupervised training, poor technique, and overuse without recovery, the same things that cause injuries in any youth sport.

Fearing the weight room because of growth plates, while treating checking, falls, and unsupervised high-volume ice time as automatically safe, gets the risk backwards. The evidence points toward supervision and technique as the real safety lever, in the gym and on the ice alike. For the full picture on evaluating a program's safety, see our youth strength training safety guide.

This article is for general education, not medical advice. If your child has a bone, joint, or growth-related health concern, talk to their doctor before starting or changing a training program.