In the 1970’s there was a research study that examined the short stature of child labors in Japan. The children were put to work at an early age doing work that involved lifting heavy objects such as hod for construction, etc. These researchers concluded that the major reason for the limited growth in these children was because lifting heavy weights broke down the epiphyseal plates (growth plates) of the long bones of the children which resulted in shorter stature than their peers. Another reason given, which was secondary, was that heavy lifting at an early age forced premature testosterone production early and this resulted in the closure of the plates. This fostered the myth of lifting weights at an early age stunted the child’s growth.
Retrospective studies done in the 90’s of the above research formed a different conclusion that the main cause of the stunted growth of these children was nutrition. It was mainly an agrarian culture with the vast majority of the children’s calories coming from vegetables and rice and very little protein. When this same cohort was studied some years later when more protein was introduced into their diet the children were found be the same stature as their peers.
Unfortunately this myth, like the muscle bound myth and full squats is harmful to the knees, still persist with those that want to believe the worst about strength training. Somewhat improbably, from that scientific finding and other similar reports, as well as from anecdotes and accreting myth, many people came to believe “that children and adolescents should not” practice weight training, said Avery Faigenbaum, a professor of exercise science at the College of New Jersey.
There is no data to support that lifting heavy weights will harm children other than injuries from inappropriate training and coaches errors in judgment. So what does the data from the NEISS (National Electronic Injury Surveillance Survey) tell us about injures to adolescence and youth and resistance training. The injury rate of adolescence Olympic weightlifter is 1.39 ( per thousand participants), youthful power lifters is about the same 1.38 and weightlifting injuries to football player in the weight room is .45. The NEISS data Report did not distinguish between injuries associated with resistance training and those associated with competitive weightlifting sports. Data were based on injuries that patients said were related to weightlifting exercises and equipment. It would incorrect to conclude injuries were caused by such activities and equipment. As a comparison to other injuries in youthful sports, the injury rate per thousand participants for HS football is 81.1, HS wrestling is 75, and judo is 542 (multiple injuries and times) and girls HS volleyball is 4.9.
Many of the reported injuries were actually caused by: poor training, excessive loading, poorly designed equipment, unsupervised access to the equipment, fatal injury of a 9 year old, where a barbell rolled off a bench press support and fell on his chest, and lack of qualified supervision
In an updated NSCA position paper (reference included), is that adolescence strength training is effective and safe with proper qualified instructions, safe equipment, etc.
Traditional area of concern for children is the potential for training induced damage to the epiphysis or growth plate. The epiphysis is the weak link in the young skeleton. The strength of cartilage is less than that of bone and damage to this area could cause the epiphysis to fuse, resulting in deformity or loss of growth.
The distal femoral physis is largest & fastest growing physis in the body.it contributes to approx:
– 70 % length of femur
– 37 % of length of entire limb
– 0.375 inch (1.0 cm) of growth / yr
– it fuses w/ metaphysis between ages of 14 & 16 yrs in girls and between ages of 16 & 18 yrs in boys.
The dark lines on the image below are the ephysis areas of the long bone of the thigh, the femur.
A few cases have been reported* on epiphysis plate fracture. Most of these injuries were due to: Improper lifting techniques, deadlift, bench press, overhead press, and maximal lifts when not prepared, and lack of qualified supervision. ( reference cited)
Bottom line is that weightlifting (RT) is safe and effective for children and adolescence with the provisos that the exercises are supervised by qualified persons, with safe equipment and environment. The myth of RT stunting growth in children has been proven to be wrong, even though it persists in many aspects of the exercised community, including pediatricians. Fractures of the ephysis is a reality but very rare in a supervised and safe environment. There is increasing evidence that increases in strength from RT in children and adolescence is mostly from the neuromuscular system rather from the muscular system, but that is another topic.
*Rowe, PH, “Cartilage fracture due to weightlifting” Brit J Sports Med. 13:130-131. 1979
Artical written by: Dr. Borden