Does Weight Training Make Children Shorter?
No, properly supervised weight training does not stunt growth or make children shorter. Multiple pediatric guidelines and research studies confirm that resistance training programs do not negatively impact linear growth in children and adolescents when appropriate safety protocols are followed 1, 2, 3.
Evidence Against Growth Stunting
The concern about weight training affecting height is a myth not supported by medical evidence:
Experimental resistance training programs did not influence growth in height and weight of pre- and early-adolescent youth across 22 reviewed studies 3. Children who participated in supervised weight training programs showed normal growth patterns identical to non-training peers.
The American Academy of Pediatrics explicitly endorses weight training for middle school-aged children (10-12 years) and adolescents when proper supervision and technique are maintained 1, 2. This endorsement would not exist if growth stunting were a legitimate concern.
Growth plate injuries from properly supervised resistance training are extremely rare, with injury rates of only 0.053-0.176 per 100 participant-hours in monitored programs 3. The theoretical concern about physeal (growth plate) damage has not materialized in clinical practice 4.
What Actually Does Affect Height
It's important to distinguish weight training from factors that genuinely impact growth:
Severe caloric restriction and malnutrition cause stunted growth, not exercise 1. Energy restriction in obese children on poorly controlled weight reduction diets has led to reductions in height velocity 1.
Nutritional stunting before age 24 months can cause irreversible growth deficits 5, but this relates to inadequate nutrition, not physical activity.
Genetic factors and parental height are the primary determinants of adult stature 6. One-third of children who are short at age 7 remain short as adults regardless of activity level, largely due to genetic programming.
Safe Weight Training Guidelines by Age
Middle School Children (10-12 years) 1, 2:
- Use small free weights with high repetitions (15-20 reps)
- Require close supervision by qualified instructors
- Demonstrate and maintain proper technique
- Avoid maximum lifts (squat lifts, clean and jerk, dead lifts)
- Focus on shorter sets rather than heavy weights
Adolescents at Physical Maturity (Tanner Stage 5) 1, 2:
- May safely progress to longer sets with heavier weights
- Can reduce repetitions while increasing resistance
- Continue emphasizing proper technique
- Still require supervision, though less intensive
Additional Benefits of Weight Training
Beyond not causing harm to growth, resistance training provides significant health benefits:
- Improves motor skills, visual tracking, and balance in developing adolescents 2
- Reduces cardiovascular risk factors including blood pressure and cholesterol 2
- Enhances bone health and body composition with increased fat-free mass 7
- Strength gains are significant and measurable in pre-pubertal and early-pubertal youth 3
Critical Safety Requirements
The key to safe weight training is proper implementation 1, 2, 4, 7:
- Medical clearance before starting
- Qualified professional instruction and supervision
- Progressive overload (gradual increase in resistance)
- Age-appropriate equipment and weight selection
- Emphasis on technique over maximum weight lifted
The bottom line: Weight training does not make children shorter when conducted with appropriate supervision, proper technique, and age-appropriate protocols. The persistent myth likely stems from theoretical concerns about growth plate injuries that have not been substantiated in actual practice.