Pumping Iron Boosts Testosterone In Kids

By Stan Lopez Senior Staff Writer
June 2, 2017

About forty years ago, child laborers were observed and it was ascertained that even with their hard life these children were unusually short. The hours spent lifting heavy objects and other extreme physical labor had inhibited their growth spurt. So from that observation and various other commonly held myths, it came to be believed "that children and adolescents should not" lift weights, said Avery Faigenbaum, a professor of exercise science at the College of New Jersey. That is now a respected belief. A recent report has stated that there are still many educators and parents who believe that children lifting weights will "result in short stature, epiphyseal plate" - or growth plate - "damage, lack of strength increases due to a lack of testosterone and a variety of safety issues."

The Research:

In the Pediatrics Journal, researchers with the Institute of Training Science and Sports Informatics in Cologne, Germany, analyzed children and weight lifting over the course of sixty years. The study was for boys and girls from ages six through eighteen. After extensive research it was proven that children almost always reaped the benefits of lifting weights. They were stronger. The effect was more dramatic with teenagers than the pre-adolescents. The gains in strength conditioning held very steady. There were no huge differences after puberty, though at that age boys are filled with an excess of testosterone. This caught the researchers off guard. Although, consistency was present throughout. The children who weight trained twice weekly showed far better improvement than the ones who trained only once per week. And the twice weekly workouts always showed a consistent gain over any who worked out once per week or less. So children who lift weights, it was proven, will not necessarily hurt themselves. And a major new review just published in Pediatrics, along with other evidence, suggests that lifting weights is safe, beneficial and absolutely required for optimal health.

Study Conclusions:

So the studies concluded that, "regardless of maturational age, children generally seem to be capable of increasing muscular strength." And, young people develop differently than adults. They rarely add bulk. Adults typically add bulk when they weight train, known as muscular hypertrophy (or commonly known as building up). Children don't normally gain muscles through weight lifting as much as an adult would, which is the reason for the surprising results of the study. Their gains involved "neurological" changes, Dr. Faigenbaum said. Their nervous systems and muscles interact differently. Other tests have proven that kids develop a larger gain in motor-unit activation within their muscles after lifting weights. A motor unit is a single neuron and all of the muscle cells that it controls. When more motor units fire, a muscle contracts more efficiently. So, strength training in kids seems to free the natural strength of their muscles, activating unused power.

The study, which disproves a commonly held belief about weight training for children - that the gains are not significant - is in line with the wisdom of most scientists who have been involved with the project. "We’ve worked with kindergartners, having them just use balloons and dowels" as weight resistance tools, "and found that they developed strength increases," said Dr. Faigenbaum, an expert on the subject of children and weight lifting. (His most recent book is called "Youth Strength Training.")

Youth Weight Lifting is Important:

And that is why weight lifting for kids is crucial, an ever growing group of experts says. "We are urban dwellers stuck in hunter-gatherer bodies," said Lyle Micheli, M.D., the director of sports medicine at Children’s Hospital Boston and professor of orthopedic surgery at Harvard University, as well as a co-author, with Dr. Faigenbaum, of the National Strength and Conditioning Association’s 2009 position paper about children and resistance training. "That’s true for children as well as adults. There was a time when children ‘weight trained’ by carrying milk pails and helping around the farm. Now few children, even young athletes, get sufficient activity" to fully strengthen their muscles, tendons and other tissues. "If a kid is a couch potato and then you throw them into a sports program, they don’t have the tissue strength to withstand the forces involved in their sports. That makes for injury."

So by lifting weights, child athletes can avoid injury, not the other way around. "The scientific literature is quite clear that strength training is safe for young people, if it’s properly supervised," Dr. Faigenbaum says. "It will not stunt growth or lead to growth-plate injuries. That doesn’t mean young people should be allowed to go down into the basement and lift Dad’s weights by themselves. That’s when you see accidents." Common injuries occur to the hands and feet. "Unsupervised kids drop weights on their toes or pinch their fingers in the machines," he said.

Staying Safe:

The best strength conditioning routines for kids are easier than expected. "The body doesn’t know the difference between a weight machine, a medicine ball, an elastic band and your own body weight," Dr. Faigenbaum said. Working with local schools, he often leads gym class warm-ups that involve passing a medicine ball (usually a "1 kilogram ball for elementary-school-age children" and heavier ones for teenagers) or holding a broomstick to teach lunges safely. He has the children doing extensive and varied exercises. They do some push-ups, perhaps one-handed on a medicine ball for older kids. (For specifics about creating strength-training programs for young athletes of various ages, including teenagers, and avoiding injury, visit strongkid.com, a Web site set up by Dr. Faigenbaum, or the Children’s Hospital Boston sports medicine site.)

When to Start:

The best age to start weight lifting, Dr. Faigenbaum said: "Any age is a good age. But there does seem to be something special about the time from about age 7 to 12. The nervous system is very plastic. The kids are very eager. It seems to be an ideal time to hard-wire strength gains and movement patterns." And if planned properly, "it can be so much fun that it never occurs to the kids that they’re getting quote-unquote ‘strength training’ at all."