Strength Training for Kids: Here is Your Preteen Strength Blueprint
22 Studies find big performance gains without growth or injury risks.
Think kids can’t benefit from strength training until their teens? Science says otherwise. This systematic review looked at over 600 prepubertal children and found that properly designed strength training for 7-12-year-olds can meaningfully improve strength, power, coordination, and body composition, without the safety risks many people still worry about.
PMID: 36981742
Key Points
Aim
To analyse the current scientific evidence on how different strength training variables (duration, frequency, intensity, volume, exercises, etc.) impact neuromuscular (performance/skills) and morphological (body composition) adaptations in healthy prepubertal children with no prior strength training.
Methods in Brief
Study Type: Systematic review (22 studies, 604 kids; avg. age ~10)
Population: Boys (n=473) & girls (n=131), all Tanner Stage I (prepubertal)
Training Programs: 104 different strength programs analysed
Variables Examined: periodisation, duration, frequency, intensity, volume, movement speed, rest, exercise type
Outcomes: Strength, jump/sprint performance, agility, coordination, balance, flexibility, lean mass, and body fat.
Results
Neuromuscular (Performance) Adaptations
Strength gains in 100% of programs — biggest improvements with:
8–12 weeks duration
2 sessions/week
Low training volume (1–2 sets, low total reps)
Moderate intensity (60–80% 1RM) for strength
Maximal movement speed for speed/power
Multi-joint & machine or plyometric exercises
Jumping & sprinting also significantly improved (especially with plyometrics & high-speed lifting)
Flexibility, agility, balance, and coordination improved in some protocols
Morphological (Body Composition) Adaptations
Body fat ↓ in 19 programs; lean mass ↑ in 17
Muscle size changes were minimal—strength gains largely from neural adaptations
Benefits were seen across sedentary, recreationally active, and sport-trained kids
Strength Training in Pregnancy: The Secret to a Happier, Healthier Nine Months
Ever wonder how strength training can make a real difference for pregnant women—especially when it comes to quality of life, pain, and mood? This review tackles the big question of whether lifting weights or doing strength exercises during pregnancy offers benefits that go beyond just aerobics—and the results are promising, but with some important caveats.
Practical Takeaways for Parents & Coaches
Start as early as 7–8 years old—if technique, safety, and supervision are in place
Two sessions per week are ideal to allow recovery
Keep sessions short and volume low to avoid overload
Start with multijoint, bodyweight, machine-based, and basic plyometric drills
Progress from technique at moderate speed to explosive intent at high speed once the basics are mastered
Expect strength, power, coordination, and body comp improvements—but not big muscle growth (that comes later with puberty hormones)
Bottom-Line
Strength training in prepubertal children is safe, effective, and highly beneficial when supervised.
Gains are from the brain and nervous system, which are getting better at controlling muscles, not from “bulking up.”
Think of it as building athletic foundations early to support lifelong fitness and lower injury risk.
Reference
Sánchez Pastor A, García-Sánchez C, Marquina Nieto M, de la Rubia A. Influence of Strength Training Variables on Neuromuscular and Morphological Adaptations in Prepubertal Children: A Systematic Review. Int J Environ Res Public Health. 2023 Mar 9;20(6):4833. doi: 10.3390/ijerph20064833. PMID: 36981742; PMCID: PMC10049541.
You can also find me at dannyleejames.com for more personal stories, training advice and coaching.