The question we get asked more than any other. What the international consensus actually says about young athletes and resistance training, and what it doesn't.
It is the first thing almost every parent asks, usually in some version of the same sentence: won't lifting weights stunt his growth? It is a fair question, it has been asked for forty years, and the answer has been settled for a while now. What has not been settled, and what actually determines whether your child is safe in a gym, is everything that comes after the word yes.
What the evidence says
The reference point is the 2014 International Consensus on youth resistance training, published in the British Journal of Sports Medicine. It was adapted from the UK Strength and Conditioning Association's position statement and then reviewed and endorsed by professional bodies across sports medicine, exercise science and paediatrics. Its conclusion is that resistance exercise can be a safe, effective and worthwhile method of conditioning for children and adolescents, provided age-appropriate training guidelines are followed.
That last clause is the whole thing. The safety finding is not a blanket permission slip, and it is not an endorsement of any room with a barbell in it. It is conditional on the training being programmed and supervised for the athlete in front of you. Strip the supervision out and you are no longer looking at the thing the research examined.
Where the growth plate myth came from
The fear traces back to a small number of case reports from decades ago, almost all involving unsupervised children attempting maximal or near-maximal lifts, frequently at home, with no instruction and no progression. That is a genuine injury risk and nobody disputes it. It is also not what supervised resistance training looks like, and building a blanket rule out of it is like banning swimming because of a case series drawn entirely from people who could not swim.
The comparison that matters is not weights versus nothing. Your child is already loading their growth plates several times a week. A contested tackle, a hard landing off a rebound, a sidestep on a wet field and a sprint into a corner all send far more force through a young joint, far less predictably, than a coached squat at a weight the athlete has earned. The consensus position is that the risk in supervised, age-appropriate resistance training is low, and that the training itself is one of the better tools available for reducing injury risk in sport.
The honest part most gyms leave out
The same consensus is careful about a second claim, and we will be too. Resistance training clearly improves muscular strength and power in adolescent athletes. Whether that automatically converts into better sport performance is less settled: around half the studies reviewed reported a positive effect on performance, but the objective evidence supporting those specific claims was limited.
So the accurate promise is that a well-run program makes an athlete stronger, more powerful and more able to tolerate the load their sport puts on them. Whether that shows up as more minutes, a higher grade or a rep jersey depends on a dozen things a gym does not control. Anyone telling you a squat number guarantees selection is selling something.
When can they start?
Readiness, not birthday. The markers we actually use are whether the athlete can follow instruction in a group setting, accept correction without disengaging, and hold a stable position under light load for the length of a set. Plenty of ten-year-olds meet all three. Some fifteen-year-olds meet none of them, and the honest answer there is to spend a block on movement quality and body weight before anything gets loaded.
It is worth saying plainly that starting is not the same as maxing. A first block for a young athlete looks like learning to brace, to hinge, to land softly and to control one leg at a time. The weight on the bar is close to the least important variable in that block.
What age-appropriate actually means
- Technique earns load. The bar does not get heavier because the calendar moved or because a training partner added weight.
- Qualified supervision, watching every set, rather than a program handed over at the door and a coach on a phone.
- Volume and intensity planned around the athlete's sport, school and season, not stacked on top of them.
- Progression measured against the athlete's own baseline rather than against the person next to them.
- Growth tracked alongside training, because a fast-growing athlete needs different loading to a stable one.
- The coach willing to take weight off, which is the hardest part and the clearest signal you are in the right room.
Questions worth asking any gym
If you are assessing a facility for your child, the useful questions are not about equipment. Ask what qualifications the person running the session holds. Ask what the coach-to-athlete ratio is on the floor. Ask how they decide when an athlete is ready to add load, and what they do when a fourteen-year-old turns up having grown five centimetres over a school holiday. Ask what they measure, and how often they measure it again.
A room that can answer those is a room where the safety finding applies. A room that cannot is one where it does not, regardless of what the research says in general.
That is why every athlete training at our Centre of Excellence is tested before they are programmed. It is not a sales exercise. It is how you find out what age-appropriate means for one specific ten to nineteen year old, rather than for a category.