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The Truth About Strength Training for Kids

Written on December 7, 2009 at 7:00 am, by Eric Cressey

A while back, I attended a seminar in Houston, and while the primary topic was how to improve pitching performance, one of my biggest takeaways was with respect to adolescent physiological development.  Long-time Phillies rehabilitation consultant Phil Donley presented some excellent data on when bones actually become skeletally mature.  The next day, another speaker made a what was, in my opinion, an uninformed comment about how kids shouldn't strength train at young ages because it would stunt their growth.

Let's start with Donley's very intriguing numbers (which have actually been available in the literature for over two decades now); we'll stick with the shoulder girdle just to keep things to-the-point.  In a baseball population, the epiphysial plate most commonly injured from throwing at the shoulder is located at the proximal humerus (Little League Shoulder); this physis (growth plate) accounts for about 80% of humeral growth, and matures by age 19 in most folks.


We've seen a lot of kids come through our door with this issue because of throwing (internal rotation of the humerus during throwing is the fastest motion in sports) and even some traumatic falls - but I can honestly say that I've NEVER seen one from strength training.  So, anecdotal evidence for me shows that strength training for kids is far from what could be considered "dangerous" for developing bones.


Now, here's where it gets more interesting: bone maturation isn't uniform across the body.  While the proximal humeral growth plate might mature at 19, the distal (down by the elbow) physis is finished between ages 10 and 16.  The proximal and distal radius plates might mature anywhere between 14 and 23.  Meanwhile, the clavicle matures at ages 22-25, and the scapula generally matures by age 22.  How many of you have ever heard of a college football being held out of weight training for all four years of his participation because all that bench pressing might stunt the growth of his clavicles and scapulae?  It just doesn't happen!  In reality, we know that the strength training benefits of increased muscle size and strength actually protect him from injury on the field.


In other words, violent (throwing) and traumatic (falling) events far exceed any stress on a young athlete's bones that we could possibly apply in a strength training setting, where the environment is controlled and overload is gradually and systematically increased over time as the athlete becomes more comfortable with it.  I'd make the argument that a young athlete should start resistance training as early as his/her attention span allows for it; the emphasis, of course, would be on body weight exercises, technical improvement, and - most importantly - keeping things fun.

If you really think about it, an athlete is placing a ton of stress (4-6 times body weight in ground reaction forces, depending on who you ask) each time he/she strides during the sprinting motion.  Kids jump out of trees all the time.  They lug around insanely heavy backpacks relative to their body mass.  Performance, general health, and self-esteem benefits aside, it's only right to give them a fighting chance in trying to avoid injury.

Also, another great point Phil made (although it was on an unrelated topic, it pertains to us) was that as an adolescent athlete grows, his center of gravity moves further up from the ground.  This is a big part of the "lapse" in coordination we see in kids during their growth spurts.  A little bit of strength goes a long way with respect to maintaining the center of gravity within the base of support, and makes an athlete more comfortable "playing low" (hip and knee flexion) to bring that center of gravity closer to the base of support.

All that said, appropriate resistance training is not only safe for kids; it's also tremendously beneficial.  In a review just published by Faigenbaum and Myer, the authors concluded:

Current research indicates that resistance training can be a safe, effective and worthwhile activity for children and adolescents provided that qualified professionals supervise all training sessions and provide age-appropriate instruction on proper lifting procedures and safe training guidelines. Regular participation in a multifaceted resistance training program that begins during the preseason and includes instruction on movement biomechanics may reduce the risk of sports-related injuries in young athletes.

Dr. Avery Faigenbaum has actually published a ton of great research (including position stands for numerous organizations) on the topic of strength training for kids in recent years; you can find all of it by searching for his last name at www.pubmed.com.

In the meantime, I hope this blog can help to eliminate the gross misconception in the general population that resistance training can't be beneficial for children.  When performed correctly and made fun, it is safe and provides tremendous benefits to kids in both the pre-adolescent and adolescent stages.

For more insights on the best approaches - and common mistakes - with training youth athletes, I'd encourage you to check out the Mike Boyle's resource, Complete Youth Training. After reviewing it, I told Mike that I enjoyed it not only as a strength and conditioning coach, but also as a parent of three daughters. I think the most compelling statement Mike made in the entire resource is that one of the most impactful things he's done with his daughter (an accomplished D1 hockey player) was to strength train a minimum of two days per week since she was 11 years old. When you've got strength at a young age - and you preserve/build it over the years - the rest of your training becomes that much more productive.

I'd strongly encourage you to check it out, whether you're a strength and conditioning professional, rehabilitation specialist, sport coach, or parent of a young athlete. There's some excellent information in there for everyone. You can learn more HERE - and it's on sale for $50 off through Sunday at midnight.

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36 Responses to “The Truth About Strength Training for Kids”

  1. Nick Koproski Says:

    It gets frustrating sometimes to hear exercise “myths” being practiced/preached as the norm today. Makes no sense that children cannot practice specified resistance training, yet they roll around, fall down and jump off things. Mabye one day this misconception will be six feet under. Dr. Avery Faigenbaum is the man.

  2. Kevin @ Team KUSA Says:


    I am the coach of a National Level Olympic Taekwondo team. Our athletes range between the ages of 8 and 14 right now. Can you please guide me on when we should start resistance training with them and how much/often?

    I’ve wanted them to do it but I don’t know enough about child physiology in regards to resistance training at this point.

    They do extremely difficult workouts for speed, agility, coordination, balance, and power, but we haven’t yet incorporated resistance (other than “rip cord” resistance bands that go on the leg when they practice their kicks or the myoplex kinetic bands when working for speed and explosiveness.

    Please give me some advice. Thanks!

  3. Derek Says:

    Thanks for a great article on a topic near to my heart.

  4. TJ Says:

    If anything, the earlier the better when it comes to establishing an extremely solid foundation. With proper instruction and fun (as noted) early on, it can only mean great things for the future, and that’s not even taking into account the relation to future sports participation.

    Get kids moving properly (or more precisely help them to maintain what they had as a baby, some might say), and teach them to enjoy physical activity while appreciating the need to progressively challenge themselves, and any benefits would be incalculable.

  5. Natalie Says:

    I love this blog. I couldn’t agree more that children to practice great and successful workout regiments aswell as adults. It is what keeps our youth strong and healthy. It also teaches discipline and responsibility to want to reach a goal. Children don’t certainly understand they are exercises if you can make it fun for them. They feel it is more of a game. We need our young ones to strive and challenge themselves. Great stuff can’t wait to read more.

  6. Rich Says:

    Mel Siff revisited.

    It’s surprising to hear that a lecturer in 2009 still believes this.

  7. Mik Says:

    How in the world are people going to give good counsel to kids if they don’t know squat about what they are doing themselves? If you pay the monthly at a exercise factory, you know that the kids who pass for trainers are telling people to do fifteen different bicep exercises, fifteen reps of eight series. You know they say nothing to the guy doing pulldowns behinds his neck. They say nothing to the guy doing curls in the squat rack. They are there to make sure the women don’t get bulky, and to make sure that no one ever squats or deadlifts. You would not want your pulse to accelerate now would you?

  8. jerry weinstein Says:

    Wolff’s Law validates the value of overload & it’s effect on bone growth(density).

    In the early days of baseball, players were known to be “country strong” as a result of their work on the farm in their primative years.


  9. Rick Kaselj Says:



    Great post.

    It is difficult to put all these groups together:
    – Children in a weightroom seeing what the maximum is they can lift
    – Children that read something on the internet about strength training for performance
    – Children in a periodized supervised program

    Rick Kaselj of http://www.ExercisesForInjuries.com


  10. Derek Shore Says:

    Great article Eric – Years ago I had the good fortune to work with Phil Donley while I worked for the Phils. He essentially designed possibly one of the most complete shoulder routines at that time. With his consultation, our athletic trainers were able to consistently determine whether a player would blow out his elbow or shoulder. These were professionals as young as 17, not amateurs. I’ve seen players ignore the warnings from the trainers and ruin their careers over it. If anything, lifting weights can only help athletes get stronger and more stable where it matters. If this is not a strong enough statement for the advocacy of using weights with youth, I don’t know what is.

  11. Eric Cressey Says:


    It’s a bit of a tough question to answer specifically. I just always remind people that it’s “resistance training,” not just “weight training.” You can use body weight stuff, bands, free weights, manual resistance, you name it. The goal at those ages is to master technique and keep it fun – and once those two goals are accomplished, you can start looking to progressively increase resistance.

    My hunch is that given the body control martial artists tend to have, they’ll be able to handle some additional loading sooner than the typical kids their age.

  12. Darrick Ervin Says:

    Good Article. Unfortunately this myth is widely spread around the world.

  13. jon Says:

    Great article! I would agree that the original person that questioned the safety of adolescent weight training was very uneducated. As a physical therapist, we need to try and change the exercise science/ physical therapy professions. It is entirely too easy to call yourself an expert now days. Just because you “call” yourself a trainer does not mean that you have any more knowledge than a person that reads a few magazine articles on exercise. Look for a trainer that is certified by either the NSCA (national strength and conditioning association) or the ACSM (american college of sports medicine). Also, We as fitness and physical therapists need to try and educate the general public on the principles of proper fitness, training, and rehabilitation.

  14. Lisa Says:

    Glad to see this one exploded.I spent my summer holidays on my grandad’s farm in Ireland and my age and size was not taken into account when piking straw and hay bales (which must have weighed at least 40kg) off the ground on a pitchfork and into a trailer, or when hauling rocks out of the ground so we could get the ground ready for sowing, or chopping big logs or flipping tires across the yard so their dad could change a flat. My cousins were the strongest, most athletic kids I’ve ever seen. They are in their 40’s now and play hurling 5 days a week and work dawn till dusk on their farms. Their fitness and strength would put guys and women half their age to shame

  15. Matt Carlin Says:

    Guys check the Australian Strength & Conditioning Position Stand on Resistance Training for Children & Adolescents. Very thorough and well researched by some of Australia’s leading S&C Coaches.


  16. Matt Carlin Says:

    Guys check the Australian Strength & Conditioning Position Stand on Resistance Training for Children & Adolescents. Very thorough and well researched by some of Australia\’s leading S&C Coaches.


  17. Steve Vieraa Says:

    Good article! I have had my 6yo son in gymnastics for about two years. I think the benefits from gymnastics will provide many benefits for physical progression from here on out. Lots of jumping, stretching and tumbling, plus balance, coordination, body awareness and strength development from bodyweight stuff. So I believe 🙂

  18. Jeff Beard Says:

    Eric, Could not agree with you more about strength training with kids. I have taken classes from Avery and I have been working with kids (age 8 and up) for a long time now and have never had an issue mainly due to I strongly supervise their form and technique and do not allow them to lift too heavy of resistence. Thanks.
    Jeff Beard

  19. Gordon Wayne Watts Says:

    I’m glad you gave hard facts on exercise and youth –I actually didn’t know for sure.

    Anyhow, these myths about “kids can’t lift weights” are not unlike *other* stupid myths I’ve recently heard:

    *** Women will look like men if they lift heavy.

    *** Supermarket milk does the body good.

    Caveat: That 2nd MISstatement is not so obvious, but see team websites to verify this this –and don’t take my word, but see and believe:

    ** http://NotMilk.com



    — or, if you’re feeling lucky: Google milk and cancer … one thing is sure: NO actual studies (peer reviewed scientific studies) have found ANY type of milk is good — they just don;t always agree on which type (skim, 2%, etc.) is most poison.

    Sorry to rant … but other countries KICK OUR BUTT in cancer rates, life-span, etc.

  20. Rees Says:

    To date, I still think this is probably one of your better pieces.

    I’m amazed at how many people are still worried about such things.

  21. Tony Dague Says:

    Adolescent female deficit in strength to weight ratio-a recipe for ACL injury. If we could somehow get the kids to strength train rather than when after injuries occur.

  22. Greyson Peltier Says:

    Is the car pushing part of the Cressey training system for kids? 🙂

  23. Russell Andrews Says:

    I train middle and high school Athletes and started my Son at 11 yrs old on the kettlebells. There wasn’t much strength gains until he hit puberty. During this pre-puberty training, he grooved his form and movement patterns. Now at 14yo and 140lbs he is highly functional, very strong, in great condition, and he does many different types of training. I don’t limit to one form of training. We do a lot of the kettlebells and body weight exercises, with a few of the power barbell choices.. I say start early with grooving the movement patterns and the strength comes later…

  24. Brad Adams Says:

    I have a question if I have a set indentical twin boys and one starts weight training at 14 and the other starts at 19, will the one that 14 be stronger by 21-24 how about bigger or heavier? given the same exact genetics to begin with? Thanks, Brad

  25. Marcus H Says:

    Store milk is bad? is this true? Can’t tell if this is legit or not? whats your take Eric?

  26. Eric Cressey Says:


    Give this series on dairy a read:


  27. Eric Cressey Says:


    I’d give the “edge” to the one who starts at a younger age.

  28. Eric Cressey Says:

    Well said, Russell.

  29. FLASH Gordon Wayne Watts Says:

    After seeing visits to my website, coming from ALL over the galaxy, and referred from your article here, Eric, I decided to see what all the furor was about…

    And, I noticed you replied to a dairy question (where the questioner apparently read my article and wanted your “doctor’s 2nd opinion”).

    Since I am not an expert on the healthiness of ‘natural’ milk (in other words, NON-pasteurized, UN-homogenized *RAW* milk -that’s NOT ‘low-fat’ or ‘non-fat’ –and which is from grass-fed cows that don’t get stuffed full of antibiotics, hormones, and other chemicals –and that don’t walk around in their own waste products while being made to produce obscenely large amounts of unsanitary milk), I decided to slowly and carefully read Brain St. Pierre’s 3-article series.

    Now that I’ve grossed everyone out (smile!) with my clarifications above, I want to say:

    THANK YOU Brian & Eric for vindicating me here… I *thought* I was right about the gross nastiness of ‘regular’ supermarket milk, but now I’m sure.

    While I admit I sometimes slip up & grab a burger (meat) or milkshake (which contains *some* milk products), I now feel “smart” once again – thanks to your 3-article series above.

    ONE QUESTION: What if I chug a small 3.1 or 3.8 fluid ounce ‘protein’ shot with whey, casein, and collagen protein sources –isn’t collegian made from ground up horse bones or something? And, isn’t casein a GLUE -and a factor in increased cancer?

    ALSO: I’ve heard that the body can only absorb & metabolize 50 grams of protein at a time. Is this so? (And, if true, could I “get around” this simply by drinking a protein shot both before *and* after my workout — and also by making sure I have “real” food as well as “supplement” protein shots?

    Thx! // Gordon //

  30. David Kittner Says:

    Great post as usual Eric! Before everyone rushes out and puts their kids through grueling strength and conditioning workouts I want to remind everyone of a few things of which I’m grateful you mentioned in your post:

    1. Keep it fun. A lot of body weight work can be done through games and activities. Make it work and you’ll the interest of the kids.

    2. Have children master movements using their own bodyweight prior to using external weight or resistance.

    2. Development of sound movement patterns is crucial when kids’ nervous systems are plastic and highly adaptable. Think simple to complex, slow to fast.

    3. Keep activities developmentally appropriate and progressive. Every activity should consist of regressions and progressions.

    4. Developing athletic foundations is a long term process not a short term event. Make the journey fun!

    5. Kids are not miniature adults. Treat them as such.

    6. Not everyone is meant to work with kids I don’t care how great they may be with adults. If you’re looking for someone who understands working with kids check out the IYCA data base for a qualified coach near you:


    Keep up the great work Eric.


  31. Matt Says:

    Please stop the dairy conversation and talk to REGISTERED DIETITIAN (not a “nutritionist,” “doctor,” “med student,” or “personal trainer” “guru” or any other “expert”) immediately!!!


    Great strength training article! I’ve recently read that strength training is great for kids and it surprised me too. http://www.exrx.net is a great strength training site with an official stance that it’s great for kids as long as it’s appropriate.

  32. Eric Cressey Says:

    Well said, David! Thanks for the contribution.

  33. Coach Cortez Says:

    Great stuff. Moderate body weight training and good nutrition is a critical need for young athletes and helps in reducing injuries.

  34. Joe Says:

    Annoying how my dad doesn’t let me lift he doesn’t understand

  35. Cindy Says:

    I am totally in favor of my 12 year old son weight training. He participates in sports year round, but I am not certain about how to determine how much is right for his body type and size… 5-3″ and 90 lbs with avg frame… from dumbbells, bench, etc….

  36. Frank Escobedo Says:

    I would add to that community gymnists and in large part dancers to that Eric. Very few athletes in other disciplines cover the varietal spectrum than those mentioned. I train ball players exclusively, some play other sports, most don’t. But of the whole, the guys who have experienced martial arts (mixed or singular), dancing or gymnastics are by far more advanced in movement quality, ROM and strength. What rings true is the resistance training effect of these “sports” than any other traditional sport our society tends toward.

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