Does Weight Lifting Stunt Growth? A Science-Based Guide to Strength Training for Kids
Quick Takeaway
Safety First: Properly supervised strength training does not stunt growth in children or adolescents.
Real Risks: Growth plate injuries are far more commonly caused by falls, collisions, and repetitive overuse — not resistance training.
The Benefits: Age-appropriate strength training improves bone density, coordination, confidence, and injury resistance.
Context Matters: Forces placed on joints during running and jumping are often higher than those during controlled lifting.
Key Principle: Movement is preventive medicine — even in childhood.
Why This Myth Exists
The belief that strength training — specifically weight lifting — stunts growth has persisted for decades. It arose from early concerns based on:
Case reports from industrial accidents
Poorly supervised lifting environments
Adult bodybuilding programs applied to children
As pediatric exercise science evolved, modern research and professional consensus became clear: properly designed, supervised strength training is safe for children and adolescents.
Myth vs. Fact: A Quick Breakdown
| The Myth | The Science-Based Fact |
|---|---|
| "Lifting weights stunts growth." | Genetics and nutrition determine height. Proper training can actually increase bone density. |
| "Kids should wait until 16 to lift." | Children can start as early as 7 or 8 (or whenever they can follow directions). The focus changes, but the activity is safe. |
| "Heavy weights destroy growth plates." | Growth plate fractures are almost exclusively caused by accidents (drops/falls) or improper form, not the resistance itself. |
| "High reps are safe; low reps are bad." | Technique matters most. Even light weights are risky if the child has poor form or lacks supervision. |
Physics Check: Putting “Heavy” Into Context
Parents often worry a dumbbell is “too heavy,” yet rarely worry about playground running.
Consider the forces involved:
Jumping & Running: Joints absorb forces of 5–7× body weight during impact.
Strength Training: A controlled squat or lift typically produces lower joint forces.
The Backpack Factor: Many children carry backpacks weighing 15–20% of body weight daily — often more load than a supervised lift.
Growth plates are living tissue designed to tolerate mechanical loading — not fragile glass structures.⁵,⁶
What the Evidence Actually Shows
Large reviews and consensus statements consistently demonstrate:
No evidence that strength training reduces final adult height
No increased risk of growth plate injury with supervised programs
Lower injury rates in youth athletes who participate in resistance and neuromuscular training
Strength training is often protective, strengthening tendons and ligaments and reducing injuries in other sports like soccer or basketball.¹⁻³,⁷
Exercise Benefits by Age Range
Early Childhood (≈5–8 years)
At this stage, “strength training” does not mean barbells.
What it looks like
Climbing, crawling, jumping
Carrying objects
Play-based movement
Benefits
Motor skill development
Balance and coordination
Early bone loading
Focus: Variety and play matter more than structure.⁴,⁵
Late Childhood / Pre-Puberty (≈9–12 years)
This is a critical window for movement literacy.
What it looks like
Bodyweight exercises (push-ups, lunges)
Resistance bands
Technique-focused instruction
Benefits
Neuromuscular control
Injury prevention
Early gains in bone density
Focus: Form, control, and confidence — not maximal load.¹,²,⁷
Adolescence (≈13–18 years)
As puberty progresses, adolescents can tolerate more structure.
What it looks like
Supervised resistance training
Progressive loading
Programs that support sports participation
Benefits
Peak bone mass development
Strength and power
Mental health and confidence
Focus: A major opportunity for lifelong musculoskeletal health.²,⁴,⁸
Why Some Elite Athletes (Like Gymnasts) Appear Short
This is selection bias — not growth suppression.
Think basketball: we don’t say basketball makes you tall. Taller athletes succeed because height helps.
Gymnastics works the same way:
Shorter, lighter athletes have mechanical advantages
They’re more likely to excel and remain in the sport
Taller athletes self-select out earlier
Long-term studies show no reduction in adult height among gymnasts.⁹
Delayed puberty can occur in some elite athletes, but this is linked to low energy availability, not resistance training.¹⁰
What Parents Should Look for in a Safe Program
1. Qualified Supervision
Supervision means qualified coaching, not just an adult present.
Look for credentials like CSCS or youth-specific certifications.¹,²
2. The 10–15 Repetition Rule
If a child can’t perform 10–15 reps with perfect form, the weight is too heavy.
Youth training should avoid 1-rep max testing and focus on technique.
3. Gradual Progression
Increase loads slowly (≈5–10%)
Only after technique is mastered
4. Enjoyment Over Intensity
If a child dreads training, it’s not sustainable.
The goal is a lifelong relationship with movement, not short-term performance.
When Exercise Becomes a Problem
The issue isn’t too much movement — it’s how movement is managed.
Risk factors include:
Sudden spikes in training volume
Inadequate rest and recovery
Poor nutrition
Early specialization pressure
These increase the risk of overuse injuries, stress fractures, burnout, and Relative Energy Deficiency in Sport (RED-S).¹⁰⁻¹²
Bottom Line
Strength training does not stunt growth when done correctly.
Age-appropriate exercise supports bone health, injury prevention, confidence, and long-term wellbeing.
The real risks come from poor supervision, excessive volume, and narrow specialization — not from kids learning to move well.
Movement is medicine, even in childhood.
References
Stricker PR, Faigenbaum AD, et al. Resistance Training for Children and Adolescents. Pediatrics. 2020.
Faigenbaum AD et al. Youth Resistance Training: NSCA Position Statement. J Strength Cond Res. 2009.
Faigenbaum AD et al. Youth Resistance Training: Past, Present, and Future. Pediatr Exerc Sci. 2009.
Lloyd RS et al. Long-Term Athletic Development. J Strength Cond Res. 2015.
Malina RM. Growth, Maturation, and Physical Activity. Human Kinetics. 2004.
Caine D et al. Growth Plate Injuries in Youth Sports. Clin J Sport Med. 2006.
Myer GD et al. Neuromuscular Training and Injury Prevention. Am J Sports Med. 2011.
Daly RM et al. Exercise and Bone Health in Children. J Bone Miner Res. 2013.
Malina RM et al. Growth and Maturation of Artistic Gymnasts. Sports Med. 2013.
Mountjoy M et al. IOC Consensus: RED-S. Br J Sports Med. 2014.
Tenforde AS et al. Overuse Injuries and Burnout in Youth Sports. Br J Sports Med. 2014.
Gabbett TJ. Training–Injury Prevention Paradox. Br J Sports Med. 2016.
McCrory P et al. Consensus Statement on Concussion in Sport. Br J Sports Med. 2017.
Medical Disclaimer
This blog is for educational purposes only and is not a substitute for medical advice. Always consult a qualified healthcare professional before starting or modifying an exercise program for your child.
