Weightlifting and resistance training are popular activities for adolescents and children seeking to improve athletic performance and overall fitness. A persistent concern among parents and coaches is the belief that lifting weights can prematurely close a young person’s growth plates, thereby stunting their final adult height. This worry stems from the idea that heavy resistance puts too much pressure on developing bones, but major medical organizations offer a different perspective.
Why Weightlifting Does Not Stunt Growth
Physical growth that determines a person’s height occurs at the epiphyseal plates, commonly known as growth plates. These are areas of cartilage near the ends of long bones, such as those in the arms and legs, where new bone tissue is generated. Once a person reaches skeletal maturity, typically by the end of puberty, these plates harden into solid bone, and no further increase in height is possible.
The myth suggests that the compressive force of lifting weights damages this cartilage, causing the plates to fuse earlier than they should. However, research and clinical reports confirm that properly designed resistance training programs have no negative effect on linear growth or the health of these plates. The controlled stress of exercise can actually promote bone density and strength.
Injuries to growth plates are rare in supervised strength training. They are more frequently associated with unmanaged acute trauma, such as a fall or collision in competitive sports like football or soccer. Although growth plates are structurally weaker than surrounding tendons and ligaments, the forces generated during non-contact sports often exceed those encountered in a controlled weight room environment. Strength gains in pre-pubescent children are primarily due to improved neuromuscular coordination, meaning the nervous system learns to better activate existing muscle fibers.
Real Risks Associated With Improper Resistance Training
While stunting growth is not a demonstrated risk, improper resistance training carries potential for injury, mainly related to poor form and excessive load. The most common injuries are soft tissue injuries, including muscle strains and tendonitis. These typically occur when an athlete attempts to lift a weight that is too heavy or uses jerky, uncontrolled movements, but they are preventable through careful training practices.
More serious, though less frequent, injuries can involve the joints and spine, such as ligament sprains, stress fractures, or disc herniation. These risks increase when young athletes attempt maximal lifts, such as a one-repetition maximum (1-RM) lift, before their bodies are skeletally mature and their technique is ingrained. Focusing on lifting the maximum possible weight shifts attention away from proper technique, placing strain on the developing musculoskeletal system.
A lack of qualified adult supervision is a major factor contributing to injury rates. Young lifters may not recognize or correct poor technique on their own, and injuries often result from accidents or “goofing around” in an unsupervised setting. Avoiding these preventable errors is the primary focus of safe youth strength training.
Guidelines for Safe Youth Strength Programs
The most important element of any safe youth strength program is prioritizing correct technique over the amount of weight lifted. Young athletes should spend time mastering movement patterns with little or no external resistance, often starting with bodyweight exercises. Only once the athlete can perform the movement perfectly should light weight be added.
All training sessions should be overseen by a qualified professional, such as a certified strength and conditioning coach or athletic trainer. This supervision ensures the program is age-appropriate and minimizes the risk of accidents from improper equipment use. Intensity should focus on sub-maximal loads, meaning weights that allow for 8 to 15 repetitions per set until moderate fatigue is reached, rather than lifting to failure.
A proper strength program should incorporate a dynamic warm-up before lifting and a cool-down period afterward, which can include stretching. Training sessions should be structured to allow for recovery, typically with strength work performed two or three days per week. Gradual progression, where resistance is increased slowly, such as by 10% increments, is the recommended method for building strength safely.