Lifting weights does not make you shorter, and there is no credible evidence that supervised resistance training damages growth plates or reduces adult height. Major pediatric and sports medicine organizations, including the American Academy of Pediatrics, have specifically dropped their older warnings against youth strength training and now recommend it as part of healthy development (AAP, 2024). The confusion mostly traces back to old, poorly designed injury reports from decades ago, not current research.
Key Takeaways
- No scientific evidence shows that properly supervised weight lifting makes a person shorter.
- Growth plates close on a hormonal timeline tied to puberty, not to whether someone lifts weights (KidsHealth).
- The “shorter by evening” feeling after a hard workout comes from spinal disc compression, and it reverses overnight (Kim et al.).
- Genetics accounts for roughly 80% of the variation in adult height between people, with nutrition, sleep, and activity filling in the rest (Visscher, in Scientific American).
- Injuries in youth lifting programs come from poor form, too much weight too soon, or no supervision, not from resistance training itself.
- The American Academy of Pediatrics and the 2014 International Consensus Statement on youth resistance training both support age-appropriate lifting programs.
Does Lifting Weights Make You Shorter? The Short Answer
No. Properly performed resistance training has never been shown to stunt growth or shrink adult height in children, teens, or adults. This idea has circulated for so long that it feels like established fact, but the research says otherwise. A 2020 clinical report published in Pediatrics concluded that well-designed resistance training programs show no negative effect on linear growth, growth plate health, or cardiovascular health in young people (Stricker et al., 2020).
The myth persists for a reasonable-sounding reason: growing bones look fragile, and lifting heavy things looks intense. Put those two ideas next to each other and the fear writes itself. But growth plates are more resilient than that image suggests, and the mechanical stress from controlled lifting tends to support bone development rather than damage it.
Where Did the Myth That Weight Lifting Stunts Growth Come From?
Early Concerns About Growth Plate Injuries
The fear started decades ago, built on isolated case reports of growth plate fractures in kids doing unsupervised, poorly programmed lifting, often in industrial labor settings rather than structured gyms. Those early reports got generalized into a blanket rule: weights stunt growth. That leap was never supported by the actual mechanism.
Growth plates, or epiphyseal plates, are bands of cartilage near the ends of long bones like the femur and tibia. They are softer than mature bone, which makes them more vulnerable to acute trauma, like a bad fall or a direct blow. But controlled, progressive loading from resistance training is a very different kind of stress than a fracture, and the two got conflated for years.
What Modern Research Says
The consensus has shifted, and it shifted a while ago. The 2014 International Consensus Statement on youth resistance training, published in the British Journal of Sports Medicine, stated plainly that concerns about harm to the developing skeleton have been replaced by evidence that childhood may actually be an ideal window for building bone mass through weight-bearing activity.
The American Academy of Pediatrics goes further, listing “stunts growth or harms growth plates” directly as a myth, with the fact being that well-designed programs show no negative effects and may help build stronger bones (AAP). The American College of Sports Medicine has reached a similar conclusion, adding that some research points to possible benefits for skeletal development rather than harm.
How Height Actually Increases During Growth
Genetics Plays the Biggest Role
Genetics explains most of the height difference between one person and the next, generally around 80% of it, based on large twin and sibling studies (Scientific American). That number varies a bit by population and sex, but the overall pattern holds across most research on the subject. Two short parents can still have a tall child, and genetics and height work in more complicated ways than a simple average of the parents’ heights would suggest.
Hormones, Nutrition, Sleep, and Physical Activity
The remaining 20% or so comes down to environment, and growth hormone release, protein and micronutrient intake, sleep quality, and general physical activity all play a part. None of these factors work in isolation. A teenager who eats well but sleeps five hours a night is still working against the system that drives most nighttime bone growth.
Weight lifting fits into that picture as one input among many, and a supportive one at that, since it stimulates bone density through mechanical loading rather than competing with the growth process.
Can Weight Lifting Damage Growth Plates?
Understanding Growth Plates
Growth plates close on a hormonal schedule tied to puberty, not to activity level. For girls, closure typically happens between ages 13 and 15; for boys, it’s usually 15 to 17, though the exact timing varies by bone and by individual (KidsHealth). Once a growth plate fuses into solid bone, that particular bone stops lengthening, whether or not the person ever picked up a weight.
When Injuries Can Actually Occur
Real injuries in youth lifting programs trace back to a short list of causes: poor technique, too much weight added too fast, no qualified supervision, or lifting through fatigue instead of resting. None of these causes are unique to weight training. A kid who runs on a bad ankle or plays through shin splints faces a similar risk profile.
The fix is not avoiding resistance training. It’s coaching, appropriate loads, and enough recovery between sessions.
Benefits of Weight Lifting for Kids and Teenagers
Stronger Bones and Muscles
Resistance training builds bone density during exactly the years when the skeleton is laying down the mineral reserves it will rely on for the rest of a person’s life. Youth strength programs have also been linked to a meaningful drop in sports-related injuries, since stronger muscles and connective tissue absorb more force before something gives out.
Better Sports Performance and Confidence
Faster sprint times, better jump height, improved balance and coordination: these are the practical payoffs coaches actually see in athletes who lift. There’s a psychological side too. Teenagers who get stronger tend to carry that confidence into other parts of competition, not just the weight room.
Safe Weight Lifting Guidelines for Young Athletes
Recommended Starting Age
There’s no single magic age. Readiness depends more on a child’s ability to follow instructions and maintain body control than on a birthday. Most pediatric guidelines suggest that once a child can participate safely in organized sports, generally around age 7 or 8, basic supervised resistance training with light loads is appropriate.
Best Practices for Safe Training
- Start with bodyweight movements before adding external load
- Prioritize form over how much weight is on the bar
- Use qualified supervision, especially early on
- Build in rest days between sessions targeting the same muscle groups
- Progress load gradually, in small increments, not by feel
Programs that follow this structure are consistent with what the does weight training stunt a child’s growth research actually supports.
Common Myths About Weight Lifting and Height
Myth: Heavy Weights Compress the Spine Permanently
Lifting does compress the spine slightly, but the effect is temporary and reverses overnight. One imaging study measuring the distance between L1 and S1 found a decrease of about 2.1% from morning to evening, driven by fluid loss in the intervertebral discs during the day (Kim et al.). That’s the same mechanism behind feeling “taller” first thing in the morning, and it happens whether or not someone lifts weights that day.
Myth: Basketball Makes You Taller but Weight Lifting Makes You Shorter
Both halves of this belief mix up correlation and causation.
| Claim | What’s Actually Happening |
|---|---|
| Basketball makes players taller | Tall people are more likely to be recruited into and stick with basketball; the sport doesn’t add inches |
| Weight lifting makes people shorter | Any apparent height loss is same-day disc compression, not a permanent change |
| Height determines sport success | Genetics sets the height ceiling well before either sport enters the picture |
Selection bias explains the basketball pattern better than biology does. Coaches recruit tall kids, and tall kids who are already good at the sport tend to keep playing it. That’s a very different mechanism than “basketball adds height,” even though the correlation in a gym full of pro players looks convincing at a glance.
Final Thoughts
Weight lifting has never been shown to make anyone shorter, at any age, when it’s done with reasonable supervision and technique. Height comes down mostly to genetics, with sleep, nutrition, and hormones filling in the rest of the picture. For parents deciding whether to let a teenager start lifting, the more useful question isn’t whether it’s safe. It’s whether the program has decent coaching behind it.
