Resistance Training in Adolescents

Video available on the internet has plenty of examples of child weight-lifters (http://www.youtube.com/watch?feature=player_embedded&v=hvQGORf674c). Policies for the use of weight gyms in schools will generally state that pupils need to be at least 14 years old. It is assumed that younger pupils using weights is not safe. Would you want your children or young clients undertaking resistance training as part of their performance enhancing or injury prevention programs? This is a question that many PE teachers will face when they working with their young athletes.

Reviews focused on the effectiveness of resistance training in children and adolescents often discuss the decades of conflicting and often damaging evidence being produced between 1960 and 1980 (Benjamin & Glow, 2003). Despite this negative history there has been a growing consensus that resistance training is beneficial. The shift was seen significantly in 1990 when the American Academy of Pediatrics stated that “recent research has shown that short-term programs in which prepubescent athletes are trained and supervised by knowledgeable adults can increase strength” in their review on strength training by children and adolescents (Committee on Sports Medicine, 1990).

The ever growing number of resistance training programs designed for children and adolescents seems to indicate that it is deemed worthwhile (Faigenbaum & Myer, 2010). In addition, to this anecdotal evidence, Behringer et al. (2010) published an analysis that demonstrates an appropriately prescribed resistance program will be effective in children and adolescents. Additionally, it was noted that larger strength gains were seen in children after the onset of puberty.

Is Resistance Training in Adolescents Safe?

Faigenbaum and Myer (2010) state that current research findings indicate a relatively low risk of injury in children and adolescents who follow age-appropriate resistance guidelines, which include qualified supervision and instruction.

Incidence of Injury

Faigenbaum and Myer (2010) came across three prospective research studies, out of a sample of 27 that were identified, that reported training related injuries in youth that interrupted training. Collectively there were 769 athletes involved. The three injuries reported were:

• Anterior shoulder pain that resolved within one week of rest
• Strain of a shoulder muscle that resulted in one missed training session
• Non-specific anterior thigh pain that resolved with 5 minutes of rest

Analysis of the data from the three studies suggests that an estimate of injury rates would be 0.176, 0.053 and 0.055 per 100 participant hours, respectively.

To put these figures into perspective, Faigenbaum and Myer (2010) identified injury rates in adolescents from a range of sports and age groups, and these figures certainly put weight lifting and resistance training in a good light. The injury rates reported are in Diagram 1.

Injury Incidence

However, they go on to report that while most of the reported injuries are muscle strains and lower back pain, if safety precautions are not followed the resulting injuries can be catastrophic. To illustrate this point they briefly present a case study; a 9 year old boy died at home when a barbell rolled off the bench press support and fell on his chest while he was playing with his brothers weights.

Location and Type of Injury

Faigenbaum and Myer (2010) identified that the back and trunk were the most frequently injured areas. One of the major concerns with injuries in youths is damage to the growth plates.

Growth Plate Injuries

Growth plates can be three to five times weaker than surrounding connective tissue, placing it at higher risk of injury with shearing and tension forces. Regrettably, injury to this section of bone could result in time lost from training and more significantly, growth disturbance. While injuries to the growth plates of youths have been reported, most of these injuries were caused by improper lifting techniques, poorly chosen training loads or lack of qualified supervision. Reports include a 13 year old boy trying to press a 30kg weight in a ‘makeshift’ home gym while alone.

The table in Diagram 2 illustrates the injury location and the exercise action and the age of the children involved in the study. 

Faigenbaum and Myer (2010)  point out that there have been no reported injuries to growth cartilage in resistance training studies that provided qualified supervision and professional guidance.

Reducing the Risks

The following are the two key factors that Faigenbaum and Myer (2010) identified as risk factors;

• Improper training technique
• Lack of qualified supervision

Thus, both the article by Faigenbaum and Myer (2010) and the American Academy of Pediatrics (2008) made recommendations on appropriate protocols for strength training in adolescents, and they included:

• Appropriate supervision by a qualified professional
• Focus on technique first, then load later
• Sub-maximal and incremental increases in load
• Ensure appropriate warm up and cool down procedures
• Ensure inclusion of exercises for all major muscle groups
• Strength training should involve 2 to 3 sets of higher repetitions (8 to 15) 2 to 3 times per week and be at least 8 weeks in duration.

Clinical Implications of This Research

Research suggests that most injuries related to youth resistance training are a result of inadequate professional supervision, which underlies poor exercise techniques and inappropriate training loads.

The risk of musculoskeletal injury resulting from age appropriate resistance training, weightlifting and plyometrics does not appear to be any greater than other sports and recreational activities in which children and adolescents regularly participate.

Comprehensive conditioning programmes designed and supervised by qualified professionals who have an understanding of youth resistance training guidelines as well as the physical and psychosocial uniqueness of children and adolescents appear to be an effective strategy for reducing sports-related injuries in young athletes.

Christopher Snell is an Australian physiotherapist who graduated from Monash University (Melbourne). Professionally he has worked with local level swimming and football (both soccer and AFL) clubs as a sports trainer, strength and conditioning coach and physiotherapist. His clinical interests include acute sports injuries, knee rehabilitation and dry needling.