Written By: Ryan Miller MS, CSCS
Resistance training, also termed strength training, is implemented across all age groups to improve health. For children and adolescents especially, it offers several benefits; some of those are increased self-esteem, increased bone mineral density (BMD), and improved body composition. But strength training among this population has encountered a strong amount of grief. Many people are doubtful because of the possibility of destroying growth plates or developing injuries. However, most, if not all, cases of injuries in children can be avoided. Research has displayed that the underlying cause of injuries to the adolescent population is the lack of sound form during training in order to ensure safety (Baechle & Earle, 2011). Most kids are able to perform the basic movements involved in such training, but performing these movements with the correct technique is the most crucial element.
A common misconception is that strength training can stunt the growth of children. Strength training has no effect on the genotypic maximum height. In fact, it actually exerts a favorable influence on growth at any stage of development as long as the proper measures are taken (Baechle & Earle, 2001). This can be seen through increases in BMD from high-impact exercises and resistance training. Children display adaptations in muscular strength, endurance, and power. Many of these adaptations occur through neural responses at the beginning a resistance training program. Most literature evaluates adaptations to neural responses, especially since invasive measures of muscular hypertrophy would be a bit unethical in children. Resistance exercises may alter anatomic and psychosocial parameters, reduce injuries, and improve motor skills and sport performance.
Strength training can also help alleviate the increasing worldwide epidemic of childhood obesity, which comes as a surprise to some. Many factors play a role in the development of childhood obesity. Strength training specifically has proven effective in combating it, because adolescents enjoy its demands and rewards, it is not as taxing or redundant as aerobic exercise, and all individuals can experience success on an individual level.
In sports, overuse injuries are the most common injuries in adolescents, and these are said to be prevented if the athletes were better prepared physically. Strength training can provide extra preparation for children in their respective sports (Benjamin, Kimberly, & Glow, 2003). Adolescents who participate in a strength training program generally exhibit increased self-esteem: they often feel successful and motivated when they can complete certain techniques flawlessly and with more weight than in a previous testing session (Faigenbaum et al., 1997). This same investigation also noted that the participants’ parents observed an increased drive to perform challenging or new daily tasks – meaning resistance training in children can not only provide physical benefits, but also behavioral ones.
Perhaps the most common concern for adolescents with resistance training involves the risk of injury to the epiphyseal plate. This is where the common notion of “stunted growth” originated. This area of the bone has not ossified and is therefore prone to injury. Epiphyseal plate injuries have been reported, but these reports came to surface from the adolescents performing heavy overhead lifts in an unsupervised setting. According to the literature, it seems that if children are taught the correct techniques, use proper loads, and are monitored by strength professionals or knowledgeable adults, these injuries occur at a minimal rate (Bernhardt et al., 2001).
Contrary to what most parents and guardians believe, resistance training can actually be an effective stimulus for bone growth and mineralization. Adverse effects have not yet been confirmed, and therefore the belief that stunted growth can occur from resistance training (RT) has not been validated (Benjamin & Glow, 2003). Resistance training often involves high-impact, weight-bearing exercises. These modalities are strongly associated with increases in BMD and bone mineral content (BMC). In the study cited above, an adolescent RT group yielded significantly higher BMD and BMC values than age-matched controls. These values were obtained in 51 school-age participants via total body DXA scan.
In another study, researchers concluded that adolescent weight-lifters who regularly train and perform heavy multi-joint compound movements display levels of BMD much higher than values of age matched controls (McKay et al., 2004). The more active a child, the more susceptible the child is to injury. This modality of exercise can potentially serve as a safety precaution to reduce possible injuries within the population by enhancing BMD and BMC values.
As a side note, BMD and BMC are often used interchangeably. However, there is a distinction. Bone mineral content (BMC) is the measurement of bone mineral found in a specific site (typically measured in the femur). Bone mineral density (BMD) is found by taking BMC values and dividing it by total area.
Bone mineral density adaptations can also be seen over an extended period of time. When resistance training is implemented during the adolescent years, the incidence of chronic conditions such as osteoarthritis and osteopenia can be significantly reduced. This time is a crucial period for formation of bones, and most peak bone formation occurs during this state of development (Behm et al., 2008). Low peak bone mass is associated with high risks of fractures and breaks, as well as an increased risk of developing osteoarthritis and osteoporosis. Higher BMD and BMC in children mean the population will be less susceptible to immediate and long-term injuries.
Another main concern is the repetitive occurrence of soft tissue injury. The low back and shoulders are most commonly used in strength movements. They are where a vast majority of soft tissue damage from repetitive use manifest. Although injuries have been reported within the literature, their severity was not fully interpreted. Most “injuries” subsided after several minutes of rest, not to mention that a meta-analysis evaluating resistance training and youth populations studied in 27 investigations revealed these injury notes: “shoulder discomfort that was resolved within a week, shoulder strain resulting in one missed training session, and leg pain that was resolved with a few minutes’ rest” (Faigenbaum et al., 2009).
When beginning a resistance training program with children, compound movements should constitute most of the lifts. These movements provide the strongest stimulus for adaptation to occur. In the beginning, they may be difficult for the child to perform. This learning period is absolutely critical in the development and enjoyment of resistance training during youth. Movements must be broken down in a phase-by phase-manner; it is very unlikely to have a child perform a squat, bench, or deadlift flawlessly.
My recommendation would be to require the young athlete to perform several sets of several bodyweight repetitions with sufficient form – particularly the movements that can be performed without using any type of bar. For instance, squats, push-ups, deadlifts, and pull-ups can all be performed without any additional equipment. Once children can perform the reps with good form and technique, you can introduce the broom stick and PVC pipe. There are also padded bars that come in lighter weights that they can begin training on before moving to the barbell.
Too often it is a race to put weight on the bar. We all know how important technique and form is for us – it should be of even great importance for the younger athlete, as this is the foundation they will lay in their resistance training journey. We must be patient and create an enjoyable learning environment for them to develop the necessary skills to partake in exercise in a safe and efficient way.
Periodization for children doesn’t have to be tricky. Ultimately, providing a way for the children to enjoy resistance training is most important. Programming certain phases within their training hasn’t received much attention within the literature. However, when looking at the grand scheme of things, children are fairly limited. They don’t possess the same cumulative response from training that we as adults do; therefore hypertrophic adaptation is limited. Nonetheless, performing a few sets of each movement in the middle rep range (8-15) will allow children to execute reps with weight while still maintaining proper form during the exercise. Once they reach the upper limit of the rep ranges, you can add additional weight.
Requiring children to resistance train in order to increase sport performance may have some merit. To date, the few studies examining resistance training and its effects in children have shown very little benefit to sport performance. However, motor skills (running, jumping, throwing, etc.) and flexibility can be significantly improved, which may lead to the notion of improved performance. Resistance training may not directly improve sport performance, but it may prepare children for successful and enjoyable sports participation (Faigenbaum et al., 2009). Children and parents looking to improve their child’s skills should focus more on training the necessary sport skills rather than strength and conditioning characteristics. Very little, if any, literature looks upon the benefit of youth training and long term sports performance.
Furthermore, as a child ages and experiences puberty, changes will start to approach significance. Training frequency evaluated in literature, and two to four times per week is typically deemed an appropriate frequency. Training any more than four days a week does not provide additional strength gains, but could be looked upon as a chore rather than an enjoyable activity. Keep sessions shorter, aim to get in, get the work done, and then get out. Lastly, parents should factor in the total amount of “work” (practices, training sessions, etc.) that their children perform on a monthly and yearly basis: allowing time for a kid to just be a kid is important.
Overall, strength training provides many beneficial outcomes, mentioned previously, and the risks can be potentially avoided all-together. Therefore, safety and monitoring during training are the most crucial factors so that each child is allowed the proper foundation and guidance to obtain benefit.
About The Author
Ryan Miller obtained his undergraduate degree in Kinesiology-Applied Exercise Science from the University of Arkansas. During that time, he was also a member of the Razorback football team. Prior to Arkansas, he spent two years at Butler County Community College where he also played football. After graduating from the U of A, Ryan went to the University of Central Missouri and completed a Master’s degree in Exercise Science. Currently, he attends the University of Oklahoma pursuing a PhD in Exercise Physiology.
Baechle, T. R., Earle, R. W., & National Strength and Conditioning Association (U.S.). (2000). Essentials of Strength Training and conditioning. Champaign, Ill: Human Kinetics.
Benjamin, H. J., & Glow, K. M. (2003). Strength training for children and adolescents. Physician and Sports Medicine, 31, 19-26.
Bernhardt, D. T., Gomez, J., Johnson, M. D., Martin, T. J., Rowland, T. W., Small, E., & Bar-Or, O. (2001). Strength training by children and adolescents. Pediatrics, 107, 1470-1472.
Faigenbaum, A., Zaichkowsky, L. D., Westcott, W. L., Long, C. J., LaRosaLoud, R., Micheli, L. J., & Outerbridge, A. R. (1997). Psychological effects of strength training on children. Journal of Sport Behavior, 20, 164-175.