Does Strength Training Stunt Growth?

Does strength training stunt growth? That is a common question and concern among parents of growing children. In this article, you’ll find out what the science says and whether you can safely let your kids hit the weights without fear that they’ll harm their bones.

Strength Training for Children: Current Recommendations

The benefits of youth strength training are numerous and well-established. Regularly lifting weights or engaging in other muscle-strengthening activities is essential for muscular fitness, regardless of age. In addition, resistance training is like a smorgasbord of positive health effects. The WHO recommends that children and adolescents perform strength training at least three times per week.¹

Despite this, many parents, trainers, teachers, coaches, and even health professionals hesitate to introduce strength training at an early age. Unfounded beliefs that lifting weights is unnecessary and unsafe for children are common to this day. One of the biggest fears is that weight training will stunt a child’s growth. 

Benefits of Strength Training for Children

Decades of scientific research show that resistance training at a young age is safe and offers many benefits that lay the foundation for a strong body and life-long health. Virtually all authorities, including the American Academy of Pediatrics and the American College of Sports Medicine, support participating in resistance training from a young age for health and performance reasons.^{2 3 4}

• Improved muscular fitness and motor skills. A low level of muscular strength is a considerable risk factor for functional disadvantages, and youth are just as vulnerable to inactivity and the consequences of muscle disuse. It’s much easier to maintain a healthy and fun habit of exercise established during childhood than doing something about a problem much later in life. 
• Increased bone mineral density. Moderate-to-high intensity resistance exercise builds bone mass and strengthens the skeleton during childhood and adolescence. Staying away from weight-bearing exercise during the growing years may lead to long-term bone-health issues later in life.
• Mental health. Strength training is good for the body and the brain. Children who lift weights show enhanced self-esteem, improved body image, and greater feelings of self-worth.
• Improved body composition. Studies show that participating in a strength training program improves body composition in overweight youth. Best of all, it creates a positive experience and promotes body positivity. Being overweight often means a reduced tolerance for aerobic training. Traditionally recommended activities such as jogging are less likely to be fun for children who are overweight or obese, and most of us, young or old, won’t keep doing something we don’t like, even if it’s good for us.
• Makes inactive kids more active. Lack of it physical activity is a big problem in today’s society. More than a quarter of the world’s adult population is not physically active enough to maintain good health. The foundations of healthy adult life are often cemented during childhood. Research shows that children participating in strength training increase their daily levels of spontaneous activity, making it a great starting point when trying to get inactive kids to become more active.
• Reduces the risk of injury. For young athletes, a training program that increases muscular strength is the most effective way to reduce sports-related injuries. Even children who don’t participate in youth sports benefit from strength training. Physical inactivity is a general risk factor for injury, and weight training prepares any child for the demands of an active, healthy lifestyle.

Does Strength Training Stunt Growth?

Despite these documented positive effects of lifting weights at an early age, the notion that resistance training during childhood will stunt linear growth lives on. It prevents many young people from taking up weight lifting, even when they want to and even though it would benefit their health and muscular development.

Growth plates, or epiphyseal plates, are layers of cartilage at the end of our long bones. They add length and width to the bones of young people during the growth period. Soon after puberty, they vanish and are replaced by solid bone.⁵

The fear that weight-lifting stunts growth in children likely stems from the belief that weight-bearing stress could cause damage to these growth plates.

Is that fear warranted? Does strength training stunt growth? According to scientific evidence, the answer is no.

Growth plates can be damaged in several ways. Physical abuse, radiation exposure, certain diseases, and neurological and genetic disorders might harm them. However, strength training and weight lifting have no apparent adverse effect on linear growth or growth plate health.^{2 3}

Epiphyseal plate fractures are prevalent in children. Unlike common bone fractures, they are more challenging to diagnose but account for around 30 % of all bone injuries.⁶ Most growth plate injuries heal fully without complications, with stunted growth being relatively rare.

Lifting weights, however, has not been implicated in children’s growth plate fractures or injuries. According to up-to-date scientific research, nothing suggests that resistance training adversely affects linear growth during childhood and adolescence. Also, lifting weights during childhood does not reduce the eventual average height or how tall someone turns out as an adult.^{7 8 9} Resistance training during childhood is associated with improved bone health, along with numerous other benefits.

Risks of Strength Training During Childhood

Of course, all types of physical exercise, strength training included, comes with a risk of injury. Youth resistance training is no exception, but this risk is no greater than in other sports where children commonly participate.¹⁰ In fact, both regular strength training and weightlifting appear safer than most other sports.¹¹

Nearly 80 % of all youth strength training-related injuries are accidental and likely preventable.¹² Instead of being a result of strength training itself, they are caused by dropped weights, pinched hands and feet, improper technique, and misuse of equipment. Kids being kids and horsing around in the weight room, in other words. That’s why supervision by a qualified trainer and proper technique is essential when introducing children to the weights.

When to Start Lifting?

Okay, so lifting weights won’t stunt your child’s bone growth, but how young is old enough to start?

A common myth is that you should wait until at least 12 years old before starting resistance training. However, according to science, children are ready for strength training as soon as they can follow instructions and observe proper form and safety rules.¹³ It’s more about mental development than physical attributes, although body awareness is also a factor to consider. Most children are ready for strength training, both mentally and physically, between the ages of 5–7.

Of course, we’re not talking about a bodybuilding or powerlifting training program at that age, but rather the introduction of strength training as an enjoyable part of experiencing physical activity. With experience, traditional strength training and weightlifting can be introduced. Experienced youth athletes can train like an adult and use heavy weights. If anything, adolescent lifters recover faster and have a lower risk of resistance training-related joint and muscle injury than adults.

There are no inherently “bad” strength-training exercises for a child. Instead of focusing on age, base exercise selection on the child’s size, experience, and motor skills. The training program should cover the entire body to ensure muscular balance. Free weights, bodyweight exercises, resistance bands, and machine-based training are effective options as part of resistance training programs for children.

Most important: the training can’t be a chore. It should be playful and fun to encourage long-term engagement and prevent boredom.

Sample Strength-Training Program for Children

In StrengthLog’s Training Program for Children and Adolescents, you’ll find both bodyweight and free-weight exercises. We designed the program according to current scientific recommendations for strength training for children. With this program, your child effectively and safely trains the entire body, strengthening all major muscle groups, gaining functional capacity, and improving balance.

It’s not a program for a 5-year-old gripping their first dumbbell, as it contains exercises that require a certain level of body awareness that come a little later. Children develop at different rates, but the age span of 9 to 12 is ideal for starting StrengthLog’s Training Program for Children and Adolescents. Older kids and adults can also follow this program to build a strong and healthy body. As a parent, you can enjoy the same workout as your child, and you’ll both benefit from it.

The program consists of two different full-body workouts. The first workout is called Workout A, and the second Workout B. Alternate between the two for a varied and fun training week, like this:

Workout A

Workout B

Workout A

Workout B

And so on.

We suggest you start with two training sessions per week, increasing the frequency to 3 times per week if and when your child wants to.

You can read more about this training program here:

>> StrengthLog’s Training Program for Children

Workout A

1. Body Weight Lunge or Dumbbell Lunge: 2 sets x 10 repetitions
2. Box Jump: 2 sets x 10 repetitions (use a lower box than in the linked instructions)
3. Bench Press: 2 sets x 10 repetitions
4. Lat Pulldown: 2 sets x 10 repetitions
5. Dumbbell Row: 2 sets x 10 repetitions
6. Back Extension: 2 sets x 10 repetitions
7. Triceps Pushdown: 2 sets x 10 repetitions
8. Dumbbell Curl: 2 sets x 10 repetitions
9. Lying Leg Raise: 2 sets x 10 repetitions
10. Plank: 1 set x max time

Workout B

1. Dumbbell Squat: 2 sets x 10 repetitions
2. Step Up: 2 sets x 10 repetitions
3. Lying Leg Curl or Seated Leg Curl: 1 set x 10 repetitions
4. Push-Up or Kneeling Push-Up: 3 sets x 10 repetitions
5. Inverted Row: 2 sets x 10 repetitions
6. Back Extension: 2 sets x 10 repetitions
7. Triceps Pushdown: 1 set x 10 repetitions
8. Dumbbell Curl: 1 set x 10 repetitions
9. Sit-Up: 1 set x 15 repetitions
10. Oblique Sit-Up: 2 sets x 15 repetitions

The program also available in the StrengthLog workout tracker. You can download StrengthLog for free using one of the buttons below.

The Bottom Line

Proper strength training is a safe form of exercise. It offers children and younger athletes strength gains and numerous health benefits.

Does strength training stunt growth?

No.

Claims that lifting weights during childhood stunts natural growth is one of the biggest myths preventing kids of all ages from hitting the weights. Fortunately, scientific evidence does not support these claims. Lifting weights is for everyone: from young children to the oldest of old.

If you liked this article, check out our in-depth review of strength training for children:

>> Strength Training For Children and Adolescents: Benefits, Risks, and Practical Recommendations

References

1. Br J Sports Med. 2020 Dec;54(24):1451-1462. World Health Organization 2020 guidelines on physical activity and sedentary behaviour.
2. Br J Sports Med. 2014 Apr;48(7):498-505. Position statement on youth resistance training: the 2014 International Consensus.
3. Pediatrics. 2020 Jun;145(6):e20201011. Resistance Training for Children and Adolescents.
4. ACSM Sports Medicine Basics. Youth Strength Training.
5. Front. Endocrinol., 09 January 2012. Genetic regulation of the growth plate.
6. StatPearls, July 31, 2021. Pediatric Physeal Injuries Overview.
7. Clinical Journal of Sport Medicine: November 2006 – Volume 16 – Issue 6 – p 478-487. Weight Training in Youth-Growth, Maturation, and Safety: An Evidence-Based Review.
8. Pediatr Endocrinol Rev. 2003 Dec;1(2):120-7. Resistance training, skeletal muscle and growth.
9. Pediatric Exercise Science 13(4):357-372. The Effect of Long-Term Resistance Training on Anthropometric Measures, Muscle Strength, and Self Concept in Pre-Pubertal Boys.
10. Br J Sports Med. 2010 Jan; 44(1): 56–63. Resistance training among young athletes: safety, efficacy and injury prevention effects.
11. Journal of Strength and Conditioning Research: February 1994 – Volume 8 – Issue 1 – p 53-57. Relative Safety of Weightlifting and Weight Training.
12. Journal of Strength and Conditioning Research: October 2009 – Volume 23 – Issue 7 – p 2054-2060. Youth Versus Adult “Weightlifting” Injuries Presenting to United States Emergency Rooms: Accidental Versus Nonaccidental Injury Mechanisms.
13. Br J Sports Med. 2022 Jun 9. Mythology of youth resistance training.