Strength training or resistance training involves the performance of physical exercises that are designed to improve strength (force production of muscles) and endurance. Long held myths have resulted in much ambiguity concerning adolescents and strength training which need to be addressed.
Perhaps the greatest myth is that strength training will result in growth plate (cartilage that hasn’t turned to bone yet) injuries. The rare case reports of epiphyseal plate fractures can in fact be attributed to misuse of equipment, improper lifting technique, lifting inappropriate amounts of weight, or training without a qualified adult trainer. Indeed, a well supervised, well designed strength training program following recommended loads, sets, and repetitions which are physique and age appropriate carries no greater risk to adolescents than any other youth sports activity. 
Another myth regarding youth and strength training is an increased incidence of soft-tissue injuries, particularly to the low back. However, similar to growth plate injuries, soft-tissue injuries are the result of poor technique, too much weight, or ballistic lifts. When injury does occur, it is most often while using free weights. Again, an organized and supervised strength training program can prevent such injuries.
Other concerns regarding adolescents and strength training include stunted growth, lack of strength increases due to a lack of testosterone, and a variety of safety issues. However, it is accepted among various associations including The American Academy of Pediatrics, American College of Sports Medicine, and British Association of Sport and Exercise Science to name a few, as well as several review articles that resistance training in youth will improve muscular strength and endurance if performed under the supervision of a qualified instructor, using proper techniques, gradual training progression, and a proper warm-up and cool-down.
Strength training, when done properly by a trained fitness professional within an adolescent’s capacity, can have many health benefits for adolescents. Strength training can favourably influence bone growth and development in youth by increasing bone mineral density. It can safely improve power, balance, and coordination as well as overall health and mental and physical well-being. In a world where technology and increasingly longer periods of sitting and inactivity are the norm, the health benefits of resistance training in adolescents outweigh the potential risks.
By: Maryann Fabrizio, Registered Physiotherapist