No, it doesn't. Properly supervised, well-designed resistance training has never been shown to damage growth plates, reduce adult height, or harm cardiovascular development in young people.
That is not a fringe position. It is the settled view of the American Academy of Pediatrics, the 2014 International Consensus on youth resistance training, and every major review published in the last two decades.
Below is where the myth came from, what the research actually found, and what "well-designed" has to mean for that evidence to apply to your kid.
Where the myth came from
The concern dates to the 1970s and 80s, when very little research existed on young people and weights. The reasoning went: growth plates can be injured, lifting loads bones, therefore lifting must injure growth plates.
It was a plausible-sounding chain of logic that nobody had tested. It spread parent to parent and coach to coach until it hardened into common knowledge. The research that followed did not support it, but by then the belief had a thirty year head start.
What growth plates actually are
Growth plates, or epiphyseal plates, are areas of cartilage near the ends of long bones. They are where lengthening happens, and they fuse in the late teens or early twenties.
They can be injured, and an injury can affect growth. But the mechanism matters. Growth plate injuries come from acute trauma: a fall from height, a collision, a bad landing, a twisting force. They are not a known consequence of progressive, supervised resistance training.
What the research found
The American Academy of Pediatrics, in its 2020 policy paper in Pediatrics, lists "resistance training stunts growth" explicitly as a myth, and states that well-designed programmes have not been shown to negatively affect growth plate health, linear growth, or cardiovascular health in youth.
The 2014 International Consensus statement, published in the British Journal of Sports Medicine and endorsed by professional bodies across sports medicine, exercise science and paediatrics, reached the same conclusion and went further, recommending resistance training as part of youth physical development.
Reviews going back decades agree. Studies of resistance training programmes in pre-adolescent and adolescent youth have consistently found no effect on height or growth rate.
The comparison nobody makes
A teenager sprinting puts several times their bodyweight through their legs with each stride. Landing from a jump generates more. A tackle in rugby, more again.
These forces comfortably exceed anything a young person encounters in a well-programmed gym session, where loads are moderate, controlled, and progressed slowly.
If a parent is comfortable with Saturday sport but not with the gym, the logic does not hold together. The gym is the more controlled of the two environments, not the less.
What it does do
The research is not merely neutral on youth strength training. It is positive.
Bone. Adolescence is when peak bone mass is built. Loading the skeleton during these years is associated with higher peak bone mass, which is the single best protection against osteoporosis in later life.
Injury prevention. Strength and neuromuscular training is among the most effective tools available for reducing sports injuries in young athletes, including knee and ACL injuries.
Movement competence. Learning to squat, hinge, land and brace transfers into every sport a young person plays.
School. Reviews have found small but consistent positive effects of youth resistance training on cognition, on-task behaviour and academic outcomes.
Mental health. A 2025 umbrella review in the Journal of the American Academy of Child & Adolescent Psychiatry, pooling 21 systematic reviews across 375 trials and over 38,000 young people, found moderate reductions in depression and anxiety symptoms among children and adolescents who exercised.
What "well-designed" has to mean
Every finding above carries the same qualifier: well-designed and properly supervised. That qualifier is doing real work, and it is worth being specific about what it excludes.
Supervision by someone qualified, not a mate and not a YouTube video.
Technique before load. Movement quality is the thing being trained in the early phase. The weight is incidental.
No maximal lifting. One-repetition-maximum testing is not appropriate for developing athletes, and the AAP says so directly.
Programming to developmental stage, not to chronological age and certainly not to what their friends are lifting.
Progression measured in months, not sessions.
An unsupervised teenager loading a barbell to impress someone is a different activity to the one the research describes. The evidence supports the second thing, not the first.
When to check with a doctor first
Talk to your GP before starting if your teenager has an existing injury, a diagnosed heart condition, is recovering from surgery, or has any medical condition where exercise capacity is a question. That is ordinary caution rather than a reflection on strength training specifically.
References
Stricker PR, Faigenbaum AD, McCambridge TM (2020). Resistance Training for Children and Adolescents. Pediatrics. https://ncys.org/wp-content/uploads/2022/10/Resistance-Training-for-Youth_AAP-Position-Paper.pdf
Lloyd RS, Faigenbaum AD, Stone MH, et al. (2014). Position statement on youth resistance training: the 2014 International Consensus. British Journal of Sports Medicine, 48(7), 498–505. https://pubmed.ncbi.nlm.nih.gov/24055781/
Faigenbaum AD, Myer GD (2010). Resistance training among young athletes: safety, efficacy and injury prevention effects. British Journal of Sports Medicine, 44(1), 56–63. https://bjsm.bmj.com/content/44/1/56
Systematic Umbrella Review and Meta-Meta-Analysis: Effectiveness of Physical Activity in Improving Depression and Anxiety in Children and Adolescents (2025). Journal of the American Academy of Child & Adolescent Psychiatry. https://www.jaacap.org/article/S0890-8567(25)00208-4/fulltext
Ministry of Health (2017). Physical Activity Guidelines for Children and Young People (5–17 years). https://www.tewhatuora.govt.nz/assets/Our-health-system/Preventative-Health/physical-activity-guidelines-for-children-and-young-people-may17.pdf
Written by Dean Williams, Founder & CEO of The Right Fit, a personal training business with studios in Epsom, Ponsonby, Takapuna and Remuera, Auckland. Cert IV and Cert V in Fitness, Master of Fitness Business (Max Fitness College). Australian Personal Trainer of the Year 2011, NSW Young Entrepreneur of the Year 2014. Last reviewed July 2026.
We run supervised strength training for teenagers aged 13–17 across our four Auckland studios.
