Does Lifting Weights at 13 Stunt Your Growth?

Lifting weights at 13 does not stunt your growth. Decades of research and position statements from major medical and sports science organizations confirm that properly supervised resistance training is safe for adolescents and does not interfere with normal height development. The fear persists largely because of a misunderstanding about growth plates and how they get injured, but the actual evidence points in the opposite direction: strength training during adolescence builds stronger bones and may even protect against the injuries that could, in rare cases, affect growth.

Where the Growth-Stunting Myth Comes From

The concern traces back to a real anatomical fact: growing bones have soft cartilage zones called growth plates near each end, and damage to those plates can, in theory, cause a bone to stop lengthening prematurely. Early case reports of young lifters sustaining injuries fueled the idea that heavy resistance training was inherently dangerous for kids. But a closer look at those reports reveals a pattern. The injuries were tied to dropped weights, maximal unsupervised lifts, improper technique, or horseplay around equipment, not to structured, progressive training programs.

A review in Sports Health found that the case reports of growth plate fractures and back injuries in young lifters were primarily attributed to misuse of equipment, inappropriate weight, improper technique, or lack of qualified adult supervision.¹ In other words, the injuries were caused by how kids were (or were not) being coached, not by the act of lifting itself. A separate review in the British Journal of Sports Medicine echoed this, noting that a majority of reported injuries in young lifters could be classified as accidental and that lack of qualified instruction was a key underlying factor.²

What Actually Damages Growth Plates

Growth plate injuries happen from specific types of force: shearing, avulsion (being pulled apart), and compressive impacts from severe twisting or direct blows. These are the forces you see in contact sports collisions, falls from height, or a heavy object dropping onto a limb. A controlled squat or overhead press does not produce these forces in the same way.³

There is a separate concern about repetitive microtrauma from extreme training volumes. Research has documented growth plate widening in skeletally immature children who participate at extreme levels, where the repetitive stress disrupts blood supply to the bone’s growing end.³ But “extreme levels” means something far beyond what a 13-year-old doing two or three sessions a week with age-appropriate loads would encounter. This kind of overuse is seen in young gymnasts training 30 or more hours per week, year-round, not in a teenager learning to bench press.

Running and Jumping Hit Harder Than Squatting

One of the most overlooked facts in this debate is that many everyday athletic activities produce higher peak forces on the body than weight training does. A study measuring ground reaction forces across different exercises found that depth jumps produced the highest peak forces and rate of force development, while back squats were comparable to jogging on rate of force development and produced lower peak ground reaction forces than jumping movements.⁴ If controlled lifting were genuinely dangerous for growth plates, sports like basketball, volleyball, and track would be far more threatening, since they involve repeated high-impact landings that slam force through the legs at higher magnitudes.

This comparison matters because many parents who worry about their 13-year-old touching a barbell have no concerns about the same child playing pickup basketball or doing plyometric drills in soccer practice. The mechanical reality is that the barbell produces a relatively smooth, predictable load compared to the jarring, uncontrolled forces of running, cutting, and landing from jumps.

What the Medical Establishment Actually Says

The National Strength and Conditioning Association’s position statement on youth resistance training is unambiguous: the benefits associated with adult resistance training are attainable by children and adolescents who follow age-appropriate guidelines.⁵ The NSCA is not an outlier here. The American Academy of Pediatrics, the British Association of Sport and Exercise Sciences, and the Canadian Society for Exercise Physiology have all published supportive statements on youth strength training when it is properly designed and supervised.

A narrative review in Sports Health examined weightlifting specifically in children and adolescents and concluded that the incidence and rate of injury appear to be relatively low, severe injury is uncommon, and the sport can be substantially safe and effective when training and competition are age-appropriate and properly supervised.⁶ The consensus across these bodies is clear: the question is not whether teens should strength train, but how to make sure they do it well.

Lifting Actually Strengthens Growing Bones

Far from weakening the skeleton, resistance training during adolescence appears to do the opposite. A meta-analysis of weight-bearing exercise programs in children and adolescents found that training significantly increased bone mineral content and bone mineral density during growth.⁷ The effect sizes were small, which is expected given that growing bones are already rapidly accruing mineral on their own, but the direction was consistently positive.

A study of adolescent male weightlifters took this further, finding that those with more training experience had greater bone mineral density across multiple body sites compared to both less experienced lifters and non-training controls.⁸ This was not limited to the sites directly stressed by lifting; the benefits were seen throughout the body. The researchers concluded that regardless of training volume, weightlifting stimulated bone mineral accrual in these adolescents.

Bone density built during adolescence matters for the rest of your life. The skeleton reaches peak bone mass in the late teens to mid-twenties, and having a higher peak acts as a buffer against bone loss later. Strength training during the teenage years is one of the most effective ways to push that peak higher.

Hormonal Responses That Support Growth

There is a worry, sometimes voiced on fitness forums, that heavy lifting somehow “uses up” growth potential or interferes with the hormones that drive adolescent development. The evidence suggests the opposite. A study of pubertal male weightlifters found that elite-level lifters had higher concentrations of growth hormone, IGF-1 (a key mediator of growth), and testosterone compared to non-training controls.⁹ These hormones were positively associated with bone outcomes, meaning the hormonal environment created by training was actively supporting skeletal development, not undermining it.

This aligns with what we know about exercise physiology in general. Resistance training is one of the strongest natural stimuli for growth hormone release. The idea that it would simultaneously stimulate growth hormone while somehow stunting growth is internally contradictory.

How a 13-Year-Old Should Actually Train

Saying “lifting is safe” does not mean “anything goes.” The safety record depends on proper programming and qualified supervision. The NSCA’s guidelines for youth resistance training are specific and practical:⁵

• Frequency: Two to three sessions per week on non-consecutive days.
• Starting point: One or two sets of 10 to 15 repetitions with a light to moderate load, focusing on learning proper technique before adding weight.
• Progression: Over time, sets and loads can increase gradually. More advanced trainees may eventually work with heavier loads in the range of 6 to 10 reps on compound exercises, but only after demonstrating consistent form.
• Supervision: All sessions should be supervised by a qualified adult, ideally someone with a recognized certification and experience working with young athletes.

The emphasis on supervision is not just a legal disclaimer. The guidelines explicitly state that if qualified supervision, age-appropriate equipment, and a safe training environment are not available, young people should not perform resistance exercise because of the increased risk of injury.⁵ A 13-year-old learning to lift with a knowledgeable coach is in a fundamentally different risk category than one loading up a barbell alone based on YouTube videos.

Proper programs also include instruction on safety procedures and warm-up protocols.¹⁰ This is not the kind of training that involves grinding through one-rep maxes or training to failure every session. For a 13-year-old, the early months should feel almost too easy on the loading side, because the goal is building movement competency first.

Strength Training Prevents Injuries in Other Sports

Here is an irony the growth-stunting myth creates: by keeping teens away from the weight room, well-meaning parents may actually be increasing their injury risk. Research on youth athletes has found that resistance training can reduce sports-related injury risk by up to about two-thirds.¹¹ That is a substantial protective effect, and it makes sense mechanistically: stronger muscles, tendons, and bones are harder to injure during the unpredictable forces of competition.

Resistance training in young athletes also improves agility, balance, speed, and coordination.¹² These are the foundational physical qualities that help a young athlete move safely and effectively, whether on a soccer pitch or a gymnastics mat. The benefits extend beyond raw strength into general athletic development.

The Real Threat to Adolescent Growth

If lifting weights does not stunt growth, what actually does? The most plausible route by which an athletic teenager could compromise their growth has nothing to do with the weight room and everything to do with the kitchen. Relative Energy Deficiency in Sport, or RED-S, is a syndrome caused by chronic low energy availability, meaning the athlete burns far more calories than they consume over extended periods. The American Academy of Pediatrics identifies RED-S as a cause of reduced performance and impairments across various physiological systems, specifically attributable to insufficient caloric intake relative to energy expenditure.¹³

In adolescents, chronic energy deficiency can delay puberty, reduce growth hormone secretion, and impair bone development. This is documented in sports where leanness is prized and caloric restriction is common: distance running, figure skating, gymnastics, wrestling at weight. The issue is not the training stimulus itself but the failure to fuel adequately around it. A 13-year-old who starts lifting and also starts eating more to match their increased energy needs is not at risk. One who adds intense training on top of poor nutrition or deliberate caloric restriction might be, regardless of whether that training involves a barbell or a track.

Maturation Varies More Than You Think

One complication that is genuinely worth understanding: 13-year-olds are not all at the same developmental stage. Some have already hit their growth spurt, while others are a year or two away from it. A study of 11- to 15-year-olds grouped by maturity status rather than chronological age found that strength training produced smaller gains in those who had not yet reached their peak growth velocity compared to those in or past it.¹⁴ Pre-growth-spurt kids still improved, just less. This does not mean they should avoid training; it means expectations should be calibrated. A pre-pubertal 13-year-old will get stronger primarily through neural adaptations rather than muscle growth, and that is perfectly fine.

Growth plate closure also follows a timeline linked to biological maturity, not calendar age. MRI data show that girls reach at least 50% growth plate fusion between ages 14 and 17, while boys reach the same milestone between 15 and 18. Full closure at all sites occurs by about age 19 in girls and 21 in boys.¹⁵ So at 13, virtually every teenager still has open growth plates. That is not a reason to avoid training. It is a reason to train intelligently, with appropriate loads and supervision, exactly as the guidelines recommend.

Psychological Benefits That Tend to Get Overlooked

The conversation about teens and weights usually stays focused on the physical side, but there is a psychological dimension worth knowing about. A study of adolescent girls who completed 12 weeks of strength training found improvements not only in strength (about 40% on average) but also in self-efficacy about weight training, confidence in confronting challenges, and general perceived effectiveness in life. The training group improved on all these measures compared to controls, who either stayed flat or declined.¹⁶

For a 13-year-old navigating the social and emotional turbulence of early adolescence, the experience of setting a goal, working progressively toward it, and seeing measurable improvement can be genuinely transformative. The weight room is one of the few environments where effort reliably produces visible results, and that feedback loop can build confidence that spills over into academics, social situations, and general resilience. The researchers in that study went so far as to suggest strength training could form the basis of new therapeutic approaches for low self-esteem in adolescent girls.

Heavy Loads in the Real World

An interesting piece of context comes from populations where children have historically carried heavy loads as part of daily life. A study of porters in eastern Nepal documented that most had begun performing long-distance portage between ages 12 and 15, carrying goods across mountain trade routes. As adults, males in the sample carried loads averaging about 73 kg, roughly 146% of their body mass.¹⁷ The adult men in this population were shorter than global averages, but disentangling the effects of childhood load-bearing from chronic nutritional scarcity, altitude, and genetic factors is essentially impossible.

What the porter data does illustrate is how different uncontrolled, repetitive, maximal load carriage in harsh conditions with limited nutrition is from supervised, progressive barbell training in a well-fed teenager. The scenarios are barely comparable. The environmental factors that most plausibly limited height in those porters, chronic caloric deficit, inadequate protein, and disease burden, had nothing to do with the mechanical act of carrying weight and everything to do with poverty. It serves as a useful reminder that when growth is compromised in physically active young people, nutrition almost always deserves the first look.