Resistance Training in Children
Pediatrics published a review of the research on resistance training in children and adolescents. The researchers concluded that the ability to improve muscle strength increases with age and maturation without noticeable advancement noted during puberty. The duration of the study and the frequency of performed sets had a positive outcome on improving muscle strength.
Reference: Behringer, Michael, vom Heede, Andreas, Yue, Zengyuan, Mester, Joachim
Effects of Resistance Training in Children and Adolescents: A Meta-analysis
Pediatrics 2010 126: e1199-e1210