Youth Strength Training: No it won’t stunt growth
There is a lot of hesitation that is involved when deciding whether or not to invest into a strength training program for youth athletes. When I mention “youth” I am referring to athletes that are preadolescent (around 11-13) and adolescent (around 14-17). These hesitations come from concerns of the safety and productivity of such training. The number one myth (yes, myth) that is introduced is the idea that strength training will stunt a kids growth.
In order for growth to be stunted there has to be a pretty traumatic event that occurs to a growth plate. A lot of force without a lot of strength to protect it. I have to be careful what I say because I would be lying if I said strength training could never damage growth plates. Because it can, if done incorrectly. In my opinion, preadolescent athletes are rarely ready to perform exercises with heavy weight (relative to their weight) until their early high school years. This is due to the fact that strength training is developmental. I tell all my athletes that you have to earn the right to put a bar on your back. This is why investing in a well-rounded and professional strength coach is a vital component to developing a youth athlete.
Information on epiphysial plate or physis (growth plates) injuries have been around for many years, but for whatever reason people ignore the reality of them. Many people do not understand how most growth plate injuries occur or the data behind these specific growth plates. First off, growth plates are responsible for the lengthening of the long bones in the body, hence the fact that injuring them can stunt a kid's growth. There are many, but one difference between adults and kids is that there are growth plates present in kids. Due to the presence of growth plates there is a chance that these growth plates can become injured through different types of mechanisms. In adults, when the bone is fully mature the growth plates will harden (ossification) and become one bone, which will significantly decrease (if any) any chance of injury happening to them. Here is the interesting part, in a non uniform manner physis throughout the body go through many years of growth until they hit full maturation. When a kid goes through a rapid growth spurt the physes, which are already weaker than the ligaments and tendons surrounding them are even more likely to get damaged. I like to think this occurs in kids who develop a lot of new growth (bone length) quickly and lose coordination (I call it the baby giraffe phase).
So the question is, why don’t athletes start strength training when bones are fully maturated? Let me answer this the best way I can. Each bone in the body reaches bone maturation at different stages in life. For instance, the growth plate at the proximal tibia will fully mature at a different time than the growth plates of the fingers. Let me put this into perspective. The growth plate that is commonly injured in youth baseball players is located at the proximal (top) humerus which is known as little league shoulder. This specific growth plate doesn’t fully mature until about the ages 17-19, which up to that point makes it possible to get injured. There is a physis at the distal (bottom) part of the radius where the wrist and hand meet that is the most common growth plate injury (gymnast wrist). This physis can mature anywhere between the ages of 14-23. Growth plate injuries in the ankle are the second most common and can lead to growing deformity in the tibia in some instances. I have seen countless youth athletes with growth plate injuries, but never have I seen one from strength training. Mechanisms such as throwing, running, falling and collisions have far more stress on a kid's growth plates than anything that can be done in the weight room. If you think about it, if you really want to decrease the chance of a kid having a growth plate injury don’t let them throw, run, ride a bike -- basically just don’t let them be a kid. If a youth athlete has been diagnosed with little league shoulder a Doctor will tell them not to throw for months. How bout this scenario, hey kid, you play baseball but I don’t want you to throw a baseball and by the way don’t forget when you get on your bike to wear your bubble wrap suit! That sounds crazy right? Because it is. This idea that strength training will stunt growth is a myth and a huge one at that. Strength training is done in one of the most controlled environments that puts emphasis on technique, quality of movement, performance enhancement and just overall fun.
So should athletes wait to strength train until they are in college when most long bones are mature? Absolutely not. Some growth plates don’t mature until the age of 25, so should college athletes not strength train? Telling a college football player that they shouldn’t lift because they may have a chance of damaging a growth plate sounds absurd. Here’s the thing, you know what is really good at preventing growth plate injuries? Muscle size and muscle strength. Strength training will increase muscle size and strength, which can act as a protecting mechanism for youth athletes while they play their sport. At the end of the day, it sounds like strength training is way more beneficial than detrimental. As I mentioned above, strength training can also help with the “Baby Giraffe” stage by accelerating the time it takes to get a youth athlete comfortable in athletic positions and movements.
If you still are not convinced, even the National Strength and Conditioning Association has made a position statement saying:
Despite outdated concerns regarding the safety or effectiveness of youth resistance training, scientific evidence and clinical impressions indicate that youth resistance training has the potential to offer observable health and fitness value to children and adolescents, provided that appropriate training guidelines are followed and qualified instruction is available. In addition to performance-related benefits, the effects of resistance training on selected health-related measures including bone health, body composition, and sports injury reduction should be recognized by teachers, coaches, parents, and health care providers. These health benefits can be safely obtained by most children and adolescents when prescribed age-appropriate resistance training guidelines.
I love the statement “despite OUTDATED concerns” because the myth that strength training will stunt a kids growth started back in the 70s and 80s. There was simply not enough evidence on the matter back then. This idea should stay in the 70s and everyone should move on to recent evidence backing the effectiveness of youth strength training.
If people care about kids and want them to perform at a high level, stay injury free and just have fun they need to invest in a proper strength and conditioning program/coach. Sports put countless amounts of stress on youth athletes due to the frequency and volume of sprinting, jumping, throwing, hitting etc.. and the best way to counteract all that stress is to perform strength training a couple times a week. As little as two 1 hour sessions a week can go a long way in preparing and developing a well-rounded athlete.
References
Faigenbaum, A., Kraemer, W., Blimkie, C., Jeffreys, I., Micheli, L., Nitka, M., & Rowland, T. (2009). Youth resistance training: Updated position statement paper from the national strength and conditioning association. Journal of Strength and Conditioning Research, 23(5), S60-S79.
