Lifting weights stunts children's growth
There is no evidence that properly supervised resistance training stunts growth in children or teenagers. Trials in pre- and early-pubertal youth show strength gains without any effect on height, injury rates in supervised programs are low, and major sports-medicine and strength organisations endorse youth resistance training.
What the science says
- Weight training reduces final height Limited evidence
Malina's 2006 evidence-based review of 22 experimental resistance training studies in pre- and early-pubertal youth found that the programs did not influence growth in height or weight. No trial has shown a lifting program shortening a child's growth.
- Supervised youth programs are relatively safe Moderate evidence
In the same review, only 10 studies monitored injuries and only three injuries were reported, at estimated rates of about 0.05-0.18 per 100 participant-hours. Malina concluded that supervised programs with low instructor-to-participant ratios are relatively safe. The data are from small, short trials, so this supports safety under supervision rather than proving it in every setting.
- Expert bodies recommend youth resistance training Moderate evidence
The NSCA's 2009 position statement (Faigenbaum and colleagues) and the 2014 International Consensus (Lloyd and colleagues, endorsed by multiple sports-medicine organisations) both conclude that appropriately prescribed and supervised resistance training is safe and beneficial for children and adolescents. These are expert consensus documents, not new trials.
What to do instead
Children and teenagers can lift, with qualified supervision, good technique and gradual progression; what matters is coaching, not avoiding weights.
Who should be careful
This page addresses a common belief; this site's programs are for healthy adults. For a child or adolescent with a medical condition, pain or a previous injury, ask a pediatrician or sports-medicine physician before starting, and always ensure qualified supervision.
Frequently asked questions
Does lifting damage growth plates or reduce height?
A review of 22 experimental programs in pre- and early-pubertal youth found no effect on growth in height or weight.
Is it safe for teenagers to lift?
Supervised programs reported very few injuries, and the NSCA (2009) and the 2014 International Consensus both endorse appropriately supervised youth resistance training.
What does a sensible youth program look like?
Qualified supervision, 2-3 non-consecutive days per week, light to moderate loads with technique first, and no unsupervised maximal lifts.
Scientific references
More myth checks
- The anabolic window (eat protein within 30 minutes of training) Limited evidence
The idea that you must get protein in within 30-60 minutes after lifting or lose your gains does not hold up.
- Muscle confusion (constantly change exercises to keep growing) Limited evidence
Muscles do not need to be "confused" to grow; they need a progressively harder stimulus.
- Spot reduction (crunches burn belly fat, leg work burns thigh fat) Limited evidence
Training a body part does not preferentially burn the fat on top of it.
- Cardio before weights ruins your gains (exercise order matters) Moderate evidence
This one is partly true.
- High reps with light weights tone, heavy weights bulk Limited evidence
There is no special "toning" rep range.
- No pain, no gain (soreness means the workout worked) Limited evidence
Muscle soreness mostly reflects how unaccustomed a workout was, not how much muscle it will build.