Lifting Weights Won’t Make Children Shorter!

Whether you are a parent, potential parent, or you know a parent, you should read this.
In the age of AirPods and wireless chargers, it’s about time we stop hearing the classic phrase: “you’re too young to lift weights”, or “lifting weights will make you short, look at all the weightlifters”, or “lifting weights will damage your bones and joints”… We can go on with all the myths we hear on a daily basis and the stuff we were exposed to while growing up and it’s about time we set it straight: you are NEVER too young to lift!
It is a common misconception that lifting weights is bad for kids and adolescents, because it assumingly puts too much stress on the bones and joints, diverts energy from bone growth so the muscles can grow instead, and the best claim among all is that when your upper traps get bigger, they push your spine down and prevent it from getting taller.
The myth that weightlifting stunts growth can be traced back to a misinterpretation of an old Japanese study on children working in mines. Researchers observed that these children were shorter than their peers and assumed the cause was lifting heavy loads. In reality, their reduced stature was far more likely explained by other factors: the chronic stress of harsh labor, poor socioeconomic conditions that affected nutrition and sleep, and spending most of their time underground with limited exposure to natural light. These influences, not resistance training, were the true contributors to their stunted growth. This historical misunderstanding continues to fuel misconceptions, especially when combined with observations about athlete body types in different sports.
These claims and misconceptions are supported by the fact that powerlifters and Olympic lifters are generally shorter (1,2). The average height of all weightlifters in the London 2012 Olympics, for example, was 166.6 cm, while the average height of all basketball players in the same event was 192.1cm (3). Basketball players were the tallest in the Olympics, while the shortest athlete was unsurprisingly a weightlifter, Lapua Lapua who is 140 cm tall/short! (3–5). But does this mean that weightlifting makes you shorter while basketball makes you taller?
NO.
 
Figure 1 - Average height of weightlifters in London Olympics 2012
The reason these athletes have such contrasting heights is not due to the type of sports they play, and it’s actually vice-versa. To excel in their respective sports, these athletes took advantage of their anthropometrics: basketball players have a better advantage when they’re tall so they can reach the net easily and be able to receive-send better passes, whereas weightlifters have a better advantage being shorter and having relatively shorter limbs, which helps them travel less distance with an incredibly heavyweight. Imagine a 192.1cm weightlifter attempt a snatch vs. a 166.6cm competitor, the taller lifter will have much more distance to travel from the bottom position, putting him in a disadvantage. This doesn’t mean that a tall person cannot become a weightlifter or a shorter person can’t be a basketball player, but this rather just explains why these overall numbers are found (you can read and watch more about the height contribution here).
A common concern about resistance training for youth is the injuries caused and delaying growth. But as long as resistance training is supervised and performed in a safe environment, it will not lead to any growth retardation, which is reported by several studies (6–8). As a matter of fact, a 1-year prospective study performed on the incidence of injuries on school children showed that resistance training contributed to only 0.7% of 1576 injuries sustained. The biggest contributors to injury were American football (19%), basketball (15%), and football (2%) (9).
Another concern and misconception about youth training is that it may crush the spine and cause injury. This concern was amplified in the 1970s and 1980s when several injuries admitted to hospitals were documented during resistance training (9,10). However, these sustained injuries turned out to be the outcome of very faulty techniques, excessive loading, poorly designed equipment, and lack of adult supervision (9). When performed safely, the benefits of resistance training on kids far outweigh any potential risk.
To sum it up, any type of physical activity that kids and adolescents perform in a safe and supervised environment is beneficial and essential for their health. Resistance training should not be feared and can actually improve bone formation and growth that is essential during the development period of a human being (11,12). Make your kids MOVE more and LIFT more!

REFERENCES
1. Keogh JWL, Hume PA, Pearson SN, Mellow P. Anthropometric dimensions of male powerlifters of varying body mass. J Sports Sci. 2007 Oct 1;25(12):1365–76.
2. Mayhew JL, Piper FC, Ware JS. Anthropometric correlates with strength performance among resistance trained athletes. J Sports Med Phys Fitness. 1993 Jun;33(2):159–65.
3. Anthropometry of Olympic Athletes 2012 [Internet]. [cited 2019 Jul 29]. Available from: https://www.topendsports.com/events/summer/science/anthropometry-2012.htm
4. Tuau Lapua Lapua Bio, Stats, and Results [Internet]. Olympics at Sports-Reference.com. [cited 2019 Jul 29]. Available from: http://www.sports-reference.com/olympics/athletes/la/tuau-lapua-lapua-1.html
5. Tuau Lapua Lapua. In: Wikipedia [Internet]. 2018 [cited 2019 Jul 29]. Available from: https://en.wikipedia.org/w/index.php?title=Tuau_Lapua_Lapua&oldid=825109236
6. Falk B, Eliakim A. Resistance training, skeletal muscle and growth. Pediatr Endocrinol Rev PER. 2003 Dec;1(2):120–7.
7. Malina RM. Weight training in youth-growth, maturation, and safety: an evidence-based review. Clin J Sport Med Off J Can Acad Sport Med. 2006 Nov;16(6):478–87.
8. Burt LA, Greene DA, Ducher G, Naughton GA. Skeletal adaptations associated with pre-pubertal gymnastics participation as determined by DXA and pQCT: a systematic review and meta-analysis. J Sci Med Sport. 2013 May;16(3):231–9.
9. Faigenbaum AD, Kraemer WJ, Blimkie CJR, Jeffreys I, Micheli LJ, Nitka M, et al. Youth resistance training: updated position statement paper from the national strength and conditioning association. J Strength Cond Res. 2009 Aug;23(5 Suppl):S60-79.
10. National Electronic Injury Surveillance System (NEISS) [Internet]. CPSC.gov. 2018 [cited 2019 Jul 30]. Available from: https://www.cpsc.gov/Research--Statistics/NEISS-Injury-Data
11. Vicente-Rodríguez G. How does exercise affect bone development during growth? Sports Med Auckl NZ. 2006;36(7):561–9.
12. Lloyd RS, Faigenbaum AD, Stone MH, Oliver JL, Jeffreys I, Moody JA, et al. Position statement on youth resistance training: the 2014 International Consensus. Br J Sports Med. 2014 Apr;48(7):498–505.