I felt the need to put this blog series together following a number of comments received on my social media in response to some of videos highlighting the work our younger athletes in the gym.
Typically, those commenting tend to disagree with the concept of children under the age of 16 lifting weights as part of their long term physical / athletic development.
It is my aim, within this series, to demonstrate how important I believe weight training actually is for children.
Despite the outdated misperceptions that resistance training was unsafe or inappropriate for youth, there is now a compelling body of scientific evidence that supports its use by children and adolescents for a wide range of performance, health, and injury reducing benefits.
Over the coming blog series, I aim to dispel some of these myths, explain the benefits of weight training for children as well as offer some basic and general guidance of how it should be prescribed safely and effectively.
Skeletal system and growth related issues:
There appears to be traditional fears and misinformed concerns that weight training can damage the developing skeleton. An idea that developing bone is more fragile and therefore at an increased chance of fracture should it be exposed to external loads such as that experienced during weight training. To offer an example, I've recently had one or two negative comments regarding some of my younger athletes being taught to squat correctly using a barbell.
I am not familiar with the origin of these concerns. If you're a parent/carer or even coach, you have every right to ensure that you are familiar and happy with what your son/daughter or athlete is being asked / advised to do. If, for some reason, you have be told they should not take part in weight training for various reasons, then I hope that this series of posts will offer some clarity and improve your confidence that weight training is in fact very important.
In my opinion, it's time we put this to bed and started looking at the bigger picture.
The idea that weight training is detrimental to youths and adolescents is arguably harmful to their long term athletic development and general health.
These worries, time and time again, have been falsified by reports and studies indicating that childhood itself may actually be the ideal opportunity to build bone mass and enhance bone structure through participating in weight training based physical activities and training (Vicente-Rodriguez, 2006; Gunter, et al. 2011)
The external loads / forces experienced by these tissues may actually make them more robust and therefore less likely to become injured.
Fears that resistance training can injure the growth-plates of youths are not supported by scientific reports, which instead indicate that the mechanical stress placed on the developing growth plates during weight training, or high strain/impact sports such as weightlifting and plyometrics are actually beneficial for bone formation and growth during both childhood and adolescence (Virvidakis, et al. 1990; Conroy, et al. 1993)
Participation in high impact sports, weight training and physical activity programmes, which include multi-joint, moderate to high intensity resistance exercise, can help to optimise bone mineral development during childhood and adolescence (Blimkie, et al. 1996; Bass, 2000; Álvarez-San Emeterio, et al. 2011; Dias Quiterio, et al. 2011)
To be clear, there is no scientific evidence indicating that weight training will have an adverse effect on growth during childhood or adolescence, nor reduce eventual height in adulthood (Falk and Eliakim 2003; Malina, 2006)
It goes without saying, of course, that the complete avoidance of sport- and physical activity related injuries is not possible. Injuries themselves are multifactorial, often relating to poor technique, fatigue/tiredness or traumatic impact (think contact related injuries in sports such as rugby, boxing, martial arts etc).
That being said, weight training programmes that are appropriately designed and sensibly progressed for youth may help to reduce the likelihood of injuries.
Generally speaking, weight training can help develop the overall robustness and resilience of tissues, improve movement literacy and coordination which in turn will help prevent injuries associated with bounding, landing, change of direction, jumping, throwing, falling etc.
Don't just take my word for it, here are some useful examples / studies to highlight this point. By looking at the date in which some of these studies where published, you'd be right to question why this age-old myth still exists today...
Lehnhard and colleagues (1996) were able to significantly reduce injury rates with the addition of a weight training programme to a male soccer team.
Cahill and Griffith (1978) incorporated weight training into their pre-season conditioning for adolescent football teams and reported a reduction in non-serious knee injuries, as well as knee injuries that typically required surgery. Not just over one, but four competitive seasons.
Hejna et al. (1982) reported that young athletes who incorporated weight training in their exercise programme suffered fewer injuries and recovered from injuries with less time spent in rehabilitation as compared to team-mates who did not weight train.
Soligard et al. (2008) successfully reduced the risk of severe and overuse injuries in female youth athletes, following the implementation of a programme that incorporated weight training exercises.
Emery and Meeuwisse (2010) reported a reduction in overall injuries and acute injury incidence in youth athletes with the use of an integrative neuromuscular training programme focused on weight training.
Of course, the more specific the weight training exercise, the more likely it is to reduce the injury risk of that specific joint or tissue. I will get on to the basics of how to structure youth weight training in another part to this blog series, however it is important to understand that weight training that is focused to address the risk factors associated with common youth sport injuries (e.g. low fitness level, muscle imbalances and errors in training) has the potential to reduce overuse injuries by up to 50% (Micheli, 2006; Valovich-McLeod, et al. 2011). That is huge!
To give you an example, several investigations indicate that reduced hamstring strength is related to both hamstring strains and ACL injury (Yamamoto, 1993; Jonhagen, 1994; Myer, et al. 2009). Weight training protocols incorporated into pre-season and in-season conditioning programmes have been found to reduce these injury risks, and also decrease anterior cruciate ligament injuries in young athletes (Hewett, et al. 2006; Myer, et al. 2006). I am sure you can appreciate how important this is when you consider that a full recovery from an ACL injury can often take longer than 18-months, and therefore be the cause of early retirement from sport.
Ultimately, well structured and long-term weight training programmes that increase muscle strength, enhance movement mechanics, and improve functional abilities such as speed, power, flexibility etc appear to be the most effective strategy for reducing sports-related injuries in young athletes (DiStefano, 2010, Emery and Meeuwisse, 2010).
Interestingly, there is also evidence supporting the use of weight training in preparing youths to withstand and tolerate exposure/introduction to sport as they transition from early school-age through to early adolescence. It is suggested that there is an apparent decline in free time and physical activity among children as they begin school (Nader, et al. 2008, Nyberg, et al. 2009) and it seems that the musculoskeletal system of some aspiring young athletes may not be prepared for the demands of sports practice and competition as a result. Research has suggested that physical activity levels in youth peak at approximately 6 years of age, and consistently decline throughout childhood and into youth (Tudor-Locke, Johnson and Katzmarzyk 2010) up until a point when they find a sport that they enjoy competing in. Consequently, the joints and tissues of some young athletes may be ill prepared to handle the demands of weekly sports practice and weekend competitions. These findings indicate that young athletes should participate regularly in resistance training programmes prior to sports seasons to reduce their risk of sports related injury. Weight training, from an early age can help prepare their tissues and skeletal system for exposure to sport, competition and increased physical activity as they grow, thus helping to reduce the likelihood of overuse related injuries.
Tissues that are strong, explosive, elastic and resilient are less likely to become strained, stressed, ruptured and inflamed. A well-structured and progressive weight training programme that has the young athlete's long term development in mind will help develop such robustness and reduce the likelihood of them getting hurt and having to take time away from training.
Video: 9 year old Scarlett's very first coaching session on the hang-clean + jerk
Part 2 will be released in the next few days detailing the long list of benefits that children can experience from incorporating regular weight training into their long term athletic development strategy
References for your own reading:
Álvarez-San Emeterio, C., Palacios-Gil Antuñano, N., López-Sobale, A.M. and González-Badillo, J.J. Effect of strength training and the practice of alpine skiing on bone mass density, growth, body composition and the strength and power of the legs of adolescent skiers. Journal of Strength and Conditioning Research, 25: 2879–2890. 2011.
Bass, S.L. The prepubertal years – a unique opportune stage of growth when the skeleton is most responsive to exercise. Sports Medicine, 30: 73-78. 2000.
Blimkie, C.J., Rice, S., Webber, C.E., Martin, J., Levy, D. and Gordon, C.L. Effects of resistance training on bone mineral content and density in adolescent females. Canadian Journal of Physiology and Pharmacology, 74: 1025–1033. 1996.
Cahill, B. and Griffith, E. Effect of preseason conditioning on the incidence and severity of high school football knee injuries. American Journal of Sports Medicine, 6: 180-184. 1978
Conroy, B.P., Kraemer, W.J., Maresh, C.M., Fleck, S.J., Stone, M.H., Fry, A.C., Miller, P.D. and Dalsky, G.P. Bone mineral density in elite junior Olympic weightlifters. Medicine and Science in Sports and Exercise, 25: 1103- 1109. 1993.
Dias Quiterio, A.L., Carnero, E.A., Baptista, F.M., and Sardinha, L.B. Skeletal mass in adolescent male athletes and nonathletes: relationships with high-impact sports. Journal of Strength and Conditioning Research, 25: 3439- 3447. 2011
DiStefano, L.J., Padua, D.A., Blackburn, J.T., Garrett, W.E., Guskiewicz, K.M., and Marshall, S.W. Integrated injury prevention program improves balance and vertical jump height in children. Journal of Strength and Conditioning Research, 24: 332-342. 2010
Emery, C.A. and Meeuwisse, W. The effectiveness of a neuromuscular prevention strategy to reduce injuries in youth soccer: a cluster-randomised controlled trial. British Journal of Sports Medicine, 44: 555-562. 2010
Falk, B. and Eliakim, A. Resistance training, skeletal muscle and growth. Paediatric Endocrinology Reviews, 1: 120-27. 2003
Gunter, K., Almstedt, H. and Janz, K. Physical activity in childhood may be the key to optimizing lifespan skeletal health. Exercise and Sports Science Reviews, 40: 13-21. 2011.
Hejna, W.F., Rosenberg, A., Buturusis, D.J. and Krieger, A. The prevention of sports injuries in high school students through strength training. National Strength Coaches Association Journal, 4: 28-31. 1982
Hewett, T.E., Ford, K.R. and Myer, G.D. Anterior Cruciate Ligament Injuries in Female Athletes: Part 2, A Meta- analysis of Neuromuscular Interventions Aimed at Injury Prevention. American Journal of Sports Medicine, 34: 490- 498. 2006
Jonhagen, S., Nemeth, G. and Eriksson, E. Hamstring injuries in sprinters: the role of concentric and eccentric hamstring muscle strength and flexibility. American Journal of Sports Medicine, 22: 262-266. 1994
Lehnhard, R.A., Lehnhard, H.R., Young, R. and Butterfield, S.A. Monitoring injuries on a college soccer team: the effect of strength training. Journal of Strength and Conditioning Research, 10: 115-119. 1996
Malina, R. Weight training in youth-growth, maturation, and safety: an evidence-based review. Clinical Journal of Sports Medicine, 16: 478-487. 2006
Micheli, L. Preventing injuries in team sports: What the team physician needs to know. In F.I.M.S. Team Physician Manual (2nd edition). K. Chan, L. Micheli, A. Smith, C. Rolf, N. Bachl, W. Frontera and T. Alenabi Eds. Hong Kong: CD Concepts, 2006. pp. 555-572.
Myer, G.D., Ford, K.R., Brent, J.L. and Hewett, T.E. The effects of plyometric versus dynamic balance training on power, balance and landing force in female athletes. Journal of Strength and Conditioning Research, 20: 345- 353. 2006
Myer, G.D., Ford, K.R., Barber Foss, K.D., Liu, C., Nick, T.G. and Hewett, T.E. The relationship of hamstrings and quadriceps strength to anterior cruciate ligament injury in female athletes. Clinical Journal of Sports Medicine, 19: 3-8. 2009
Nader, P., Bradley, R., Houts, R., McRitchie, S. and O’Brien, M. Moderate to vigorous physical activity from ages 9 to 15 years. The Journal of the American Medical Association, 300: 295-305. 2008
Nyberg, G., Nordenfelt, A., Ekelund, U. and Marcus, C. Physical activity patterns measured by accelerometry in 6- to 10-yr-old children. Medicine and Science in Sports and Exercise, 41: 1842-1848. 2009
Soligard, T., Mycklebust, G., Steffen, K., Holme, I., Silvers, H., Bizzini, M., Junge, A., Dvorak, J., Bahr, R. and Andersen, T.E. Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomized controlled trial. British Medical Journal, 337: a2469. 2008
Tudor-Locke, C., Johnson, W.D. and Katzmarzyk, P.T. Accelerometer-determined steps per day in US children and youth. Medicine and Science in Sports and Exercise, 42: 2244-2250. 2010.
Valovich-McLeod, T.C., Decoster, L.C., Loud, K.J., Micheli, L., Parker, J.T., Sandrey, M.A. and White C. National Athletic Trainers’ Association position statement: prevention of pediatric overuse injuries. Journal of Athletic Training, 46: 206-220. 2011
Vicente-Rodriguez, G. How does exercise affect bone development during growth? Sports Medicine. 36: 561-569. 2006.
Virvidakis, K., Georgiu, E., Korkotsidis, A., Ntalles, A. and Proukakis, C. Bone mineral content of junior competitive weightlifters. International Journal of Sports Medicine, 11: 244-246. 1990.
Yamamoto, T. Relationship between hamstring strains and leg muscle strength. A follow-up study of collegiate track and field athletes. Journal of Sports Medicine and Physical Fitness, 33: 194-199. 1993