“Do not do weights at a young age – It will stunt your growth!”
It has been a popular belief for years that weight training is not good for children, even for adolescents, since they have not yet reached their full stature, as it will stunt their growth.
Is this true?
Not long time ago, I overheard a gym member preaching another one that had brought his 16 year old son, that it is not good for the boy to do weights as it will stunt his growth. The suggestion was to “just do pull ups, as stretching the body helps with attaining a taller stature”.
I could not help myself while listening and I had to go and ask that person if he knew how the body grows… His response was “during sleep”. I was like “exactly, you are right. But how?”, then he said that he did not know the details.
So let’s delve into the biological mechanism behind growing taller.
Sleep is definitely an important part of growth. No wonder we exhibit most of our growth during our infancy, when we mostly spend our time sleeping!
During sleep, a hormone called “growth hormone” is secreted.1 As the name implies, this hormone is responsible for growth.2,3 GH increases the levels of IGF-1 which in turn stimulates cell proliferation within the bone and bone growth (both in length and density).
During puberty we have a second growth sprout. This is due to elevated levels of GH again as well as the sex hormones, i.e. testosterone and oestrogen. The two latter initially contribute to bone growth by increasing the levels of GH further, whereas towards the end of adolescence they act as a stop signal for growth, by promoting closure of the epiphyseal growth plates within the bone. 3
Exercise using weights leads to increases in both GH as well as testosterone.4 Higher intensity training (e.g. lifting weights closer to your maximum strength) results in greater release of these hormones, especially testosterone.
Research shows that weight training does not stunt the growth in pre-adolescent and early-pubertal children.5
On the contrary, since GH is the main growth promoting hormone it is a way to facilitate growth and increase the chances of reaching the full genetic potential in terms of stature. Other significant determinants of growth, are genetics and nutrition, with meeting energy and protein needs being of paramount importance.
But then why are most weightlifters short?
This does not have to do with their training hindering growth. It is just a matter of short levers being advantageous for lifting heavy weights, and thus the ones that make it to the elite level and are well known happen to be of that body shape because it allows them to lift heavier, and thus they have been selected to represent their countries.
Notable examples being Naim Suleymanoglu in weightlifting and Sergey Fedosienko in powerlifting. Both these athletes have very short femurs and arms favouring their lifts.
Concluding, weight training stunting growth is a myth that is busted, So feel free to encourage your children to enjoy the benefits of weight training.
Please make sure though that proper form is followed and this is done in a safe manner!
Stay active and healthy!
The Nutrigenius Team
1. Ribeiro-Oliveira A, Barkan AL. Growth Hormone Pulsatility and its Impact on Growth and Metabolism in Humans. in K Ho (ed), Growth Hormone Related Diseases and Therapy: A Molecular and Physiological Perspective for the Clinician, Contemporary Endocrinology. 2011:33-56
2. Olarescu NC, Gunawardane K, Hansen TK, et al. Normal Physiology of Growth Hormone in Adults. [Updated 2019 Oct 16]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South
3. Murray PG, Clayton PE. Disorders of Growth Hormone in Childhood. [Updated 2016 Nov 16]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK278971/
Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279056/
4. Craig BW, Brown R, Everhart J. Effects of progressive resistance training on growth hormone and testosterone levels in young and elderly subjects. Mech Ageing Dev. 1989;49(2):159‐169. doi:10.1016/0047-6374(89)90099-7
5. Malina RM. Weight training in youth-growth, maturation, and safety: an evidence-based review. Clin J Sport Med. 2006;16(6):478‐487. doi:10.1097/01.jsm.0000248843.31874.be