Some of the most serious and prevalent chronic health conditions facing children today include obesity, which has risen from 5% in the early 1970s to more than 25% today. Also, asthma has nearly doubled in prevalence from the 1980s, and type 2 diabetes has risen by 43% [1].



We have a generation defined by physical inactivity, labor-saving technological advances combined with abundant supply of energy-dense foods. Essentially this environment has accelerated the development of adult-related chronic disease conditions in children and adolescents, ensuring a shorter lifespan and extended suffering throughout their lifetime, unless something is done soon to reverse this trend.

Why resistance exercise?

From a physiological perspective, no other form of activity provides so many health benefits. Recent findings indicate that resistance exercise can offer unique benefits for children and adolescents when appropriately prescribed and supervised. Children and teens can improve cardiovascular risk profile, facilitate weight control, strengthen bone, enhance psychological well-being, improve motor performance skills, and increase resistance to sports-related injuries.

In fact, a compelling body of scientific evidence indicates that children and adolescents can significantly increase their strength above and beyond growth and maturation; providing that the resistance exercise program is structured correctly in terms of intensity, volume, and duration. [2-5]

Body composition

The potential influence of resistance exercise on body composition has become an important topic of investigation, given that the prevalence of obesity among children and adolescents continues to increase worldwide [8]. Currently, childhood obesity, with its associated comorbidities (e.g., type 2 diabetes) and their likelihood of persistence into adulthood are critical public health threats. It has recently been suggested that resistance exercise may offer observable health value to obese children and adolescents [9].

The nature of resistance exercise which is characterized by short periods of physical activity interspersed with brief rest periods between sets and exercises is more consistent with how youth move and play [10] and allow obese youth to enjoy resistance exercise. Several studies reported favorable changes in body composition in children and adolescents who were obese or at risk for obesity after participation in a resistance exercise program [11-13]. For example, participation in a 16-wk resistance exercise program significantly decreased body fat and significantly increased insulin sensitivity in adolescent males who were at risk for obesity [13].

There is even some data to suggest that resistance exercise may be an effective nonpharmacologic intervention in hypertensive adolescents, provided submaximal loads are used and proper exercise procedures are followed [14]. Also, limited data suggests that resistance exercise characterized by moderate loads and a high number of repetitions can have a positive influence on the blood lipid profile of children [15].

participation in a 16-wk resistance exercise program significantly decreased body fat and significantly increased insulin sensitivity in adolescent males who were at risk for obesity

Is it safe?

Contrary popular belief, resistance exercise is a very safe activity. As with most physical activities, resistance exercise does carry some degree of inherent risk of musculoskeletal injury, yet this risk is no greater than the risk associated with many other sports and recreational activities in which children and adolescents regularly participate. Current findings indicate that a very low risk of injury in children and adolescents that adhere to age-appropriate resistance training guidelines [1,2].

The contention that the overall health of children and adolescents is likely to improve rather than be adversely affected by regular participation in a resistance exercise program is supported by statements from professional organizations such as the American Orthopaedic Society for Sports Medicine, Canadian Society for Exercise Physiology [6], British Association of Exercise and Sport Sciences, IOC Consensus Statement [7] and National Association for Sports and Physical Education. The potential positive influence of these good health habits developed in children and adolescents on the adult lifestyle should be recognized.

Dispelling the myth

There is the traditional concern that resistance exercise would be harmful to the immature bones of kids and teens. An area of concern related to youth resistance exercise is the potential for training-induced damage to the growth cartilage, which is found at 3 main sites in a growing child’s body: the growth plates near the ends of the long bones, the cartilage lining the joint surfaces (articular cartilage), and the points at which the major tendons attach to the bones (apophysis).

Because growth cartilage is ‘‘pre-bone,’’ it is weaker than adjacent connective tissue and therefore more easily damaged by repetitive microtrauma. In some cases, damage to this area of the bone could result in time lost from training, significant discomfort, and growth disturbances [30]. The greatest concern for youth who are following a resistance exercise program may be the risk of repetitive-use soft tissue injuries. In particular, the risk of injury to the lower back and shoulder are of concern [31]. So the risk is more from incorrect repetition and loading, not the activity itself. To eliminate any potential risk, expert instruction and supervision is a necessity with children and teens participating in resistance exercise.

If resistance exercise guidelines are followed, regular participation in resistance exercise can maximize bone mineral density during childhood and adolescence [18]. Additionally, there is no detrimental effect of resistance exercise on linear growth in children and adolescents.

the risk is more from incorrect repetition and loading, not the activity itself. To eliminate any potential risk, expert instruction and supervision is a necessity with children and teens participating in resistance exercise.

In fact it has been demonstrated that adolescent weightlifters displayed levels of bone mineral density [19] and bone mineral content [20] well above values of age-matched controls. It appears that the osteogenic response to exercise in youth can be enhanced by sensibly prescribing multi-joint, moderate to high intensity Pinnacle exercises, such as bench press, squat and their variations.

Important considerations

Obviously, an increase in sports participation by youth is desired – we all want out kids to be more active and reap the social integration and benefits that sports provide. However, an alarming number of sports-related injuries are regularly documented in the ill-prepared or improperly trained young athlete [21,22]. Sport-related injuries are a significant cause of hospitalization and health care costs during childhood and adolescence [23] and are also one reason why some young athletes drop out of sports [24].

 

regular participation in resistance exercise can maximize bone mineral density during childhood and adolescence...there is no detrimental effect of resistance exercise on linear bone growth.

Preseason conditioning programs that included resistance exercise decrease the number and severity of injuries in high school football players [26] and the incidence of injury in adolescent soccer players [27]. Also, reduce the incidence of serious knee injuries in adolescent female athletes [28]. Therefore, an appropriately designed resistance exercise program may help reduce the likelihood of sports-related injuries in young athletes [25].

Contrary popular belief, resistance exercise is a very safe activity, any risk is no greater than the risk associated with many other sports and recreational activities in which children and adolescents regularly participate

Resistance Training Guidelines for Children and Adolescents

• To date, no scientific evidence indicates that a correctly structured resistance training program designed by an accredited professional is a higher-risk activity than other sports and activities in which youth regularly participate.

• There is no minimal age requirement for participation in a youth resistance exercise program. However, children should have the emotional maturity to follow direction and should be eager to try this type of activity. Conversely, The Personal Trainer should develop the skills to coach age-group participants at a level they understand.

• Trainers and parents should be aware of the considerable amount of time it takes to teach correct lifting and progression. The two most important considerations in the development of programs are the quality of instruction and rate of progression. This is why expert instruction for children & teens is paramount.

• The greatest concern may be the risk of repetitive-use soft tissue injuries. In particular, the risk of injury to the lower back and shoulders [31]. This is why expert supervision must be maintained for children & teens. Parents may want little Johnny or Mary to perform resistance exercises correctly, but they must be wiling to invest in a professional to supervise every session!

• All training modalities can be safely and effectively implemented; resistance machines, free weights, medicine balls; elastic bands, isometric contractions, and body weight exercises. Although a limitless number of exercises can be used to enhance muscular strength in children, it’s important to consider a child’s body size, fitness level, and exercise technique experience. The choice of exercises should promote muscle balance across joints and between opposing muscle groups (e.g. quadriceps and hamstrings) [1].

• Above all the goals should include teaching children about their bodies, promoting an interest in physical activity and having fun.
It is obviously important for coaches and trainers to work with established, up-to-date guidelines. That’s why Metabolic Precision implements the most progressive, internationally recognized guidelines within one complete science-based, research-proven, system.

This article is a small part of a Complete Guide to Resistance Exercise With Special Populations - just one part of the MP Level 2 Transformation Specialist Certification. Learn more here.






Dr. Paul Henning is leading scientist at the Military Performance Division, United States Army Research Institute of Environmental Medicine. Paul's an avid bodybuilder, lives the MP lifestyle and is a proud member of the MP Team. Read more from Dr Henning here.






References:
1. Faigenbaum, A.D., et al., Youth resistance training: updated position statement paper from the national strength and conditioning association. J Strength Cond Res, 2009. 23(5 Suppl): p. S60-79.
2. Brown, E.W. and R.G. Kimball, Medical history associated with adolescent powerlifting. Pediatrics, 1983. 72(5): p. 636-44.
3. Blimkie, C.J., et al., Effects of resistance training on bone mineral content and density in adolescent females. Can J Physiol Pharmacol, 1996. 74(9): p. 1025-33.
4. Faigenbaum, A.D., et al., Effects of different resistance training protocols on upper-body strength and endurance development in children. J Strength Cond Res, 2001. 15(4): p. 459-65.
5. Faigenbaum, A.D., et al., Preliminary evaluation of an after-school resistance training program for improving physical fitness in middle school-age boys. Perceptual and motor skills, 2007. 104(2): p. 407-15.
6. Behm, D.G., et al., Canadian Society for Exercise Physiology position paper: resistance training in children and adolescents. Appl Physiol Nutr Metab, 2008. 33(3): p. 547-61.
7. Mountjoy, M., et al., IOC consensus statement on training the elite child athlete. Clin J Sport Med, 2008. 18(2): p. 122-3.
8. Ogden, C.L., et al., Prevalence of overweight and obesity in the United States, 1999-2004. JAMA, 2006. 295(13): p. 1549-55.
9. Benson, A.C., M.E. Torode, and M.A. Fiatarone Singh, Effects of resistance training on metabolic fitness in children and adolescents: a systematic review. Obes Rev, 2008. 9(1): p. 43-66.
10. Bailey, R.C., et al., The level and tempo of children's physical activities: an observational study. Med Sci Sports Exerc, 1995. 27(7): p. 1033-41.
11. Benson, A.C., M.E. Torode, and M.A. Fiatarone Singh, The effect of high-intensity progressive resistance training on adiposity in children: a randomized controlled trial. Int J Obes (Lond), 2008. 32(6): p. 1016-27.
12. Schwingshandl, J., et al., Effect of an individualised training programme during weight reduction on body composition: a randomised trial. Arch Dis Child, 1999. 81(5): p. 426-8.
13. Shaibi, G.Q., et al., Effects of resistance training on insulin sensitivity in overweight Latino adolescent males. Med Sci Sports Exerc, 2006. 38(7): p. 1208-15.
14. Hagberg, J.M., et al., Effect of weight training on blood pressure and hemodynamics in hypertensive adolescents. J Pediatr, 1984. 104(1): p. 147-51.
15. Sung, R.Y., et al., Effects of dietary intervention and strength training on blood lipid level in obese children. Arch Dis Child, 2002. 86(6): p. 407-10.
16. Bass, S.L., The prepubertal years: a uniquely opportune stage of growth when the skeleton is most responsive to exercise? Sports Med, 2000. 30(2): p. 73-8.
17. Hind, K. and M. Burrows, Weight-bearing exercise and bone mineral accrual in children and adolescents: a review of controlled trials. Bone, 2007. 40(1): p. 14-27.
18. Turner, C.H. and A.G. Robling, Designing exercise regimens to increase bone strength. Exerc Sport Sci Rev, 2003. 31(1): p. 45-50.
19. Conroy, B.P., et al., Bone mineral density in elite junior Olympic weightlifters. Med Sci Sports Exerc, 1993. 25(10): p. 1103-9.
20. Virvidakis, K., et al., Bone mineral content of junior competitive weightlifters. Int J Sports Med, 1990. 11(3): p. 244-6.
21. Intensive training and sports specialization in young athletes. American Academy of Pediatrics. Committee on Sports Medicine and Fitness. Pediatrics, 2000. 106(1 Pt 1): p. 154-7.
22. Caine, D., C. Caine, and N. Maffulli, Incidence and distribution of pediatric sport-related injuries. Clin J Sport Med, 2006. 16(6): p. 500-13.
23. Micheli, L.J., R. Glassman, and M. Klein, The prevention of sports injuries in children. Clin Sports Med, 2000. 19(4): p. 821-34, ix.
24. Grimmer, K.A., D. Jones, and J. Williams, Prevalence of adolescent injury from recreational exercise: an Australian perspective. J Adolesc Health, 2000. 27(4): p. 266-72.
25. Abernethy, L. and C. Bleakley, Strategies to prevent injury in adolescent sport: a systematic review. Br J Sports Med, 2007. 41(10): p. 627-38.
26. Cahill, B.R. and E.H. Griffith, Effect of preseason conditioning on the incidence and severity of high school football knee injuries. Am J Sports Med, 1978. 6(4): p. 180-4.
27. Heidt, R.S., Jr., et al., Avoidance of soccer injuries with preseason conditioning. Am J Sports Med, 2000. 28(5): p. 659-62.
28. Mandelbaum, B.R., et al., Effectiveness of a neuromuscular and proprioceptive training program in preventing anterior cruciate ligament injuries in female athletes: 2-year follow-up. Am J Sports Med, 2005. 33(7): p. 1003-10.
29. Risser, W.L., J.M. Risser, and D. Preston, Weight-training injuries in adolescents. Am J Dis Child, 1990. 144(9): p. 1015-7.
30. Caine, D., J. DiFiori, and N. Maffulli, Physeal injuries in children's and youth sports: reasons for concern? Br J Sports Med, 2006. 40(9): p. 749-60.
31. Risser, W.L., Weight-training injuries in children and adolescents. Am Fam Physician, 1991. 44(6): p. 2104-8.