JGfromtheNW wrote:What ages we talking about? Kids who are pre-puberty should not be lifting weights (as a general rule) for various reasons.
Karate and Martial Arts are indeed some of the best ways to teach a child discipline, respect and self-defense.
I'd like to know the 'general rule' that lays out the various reasons as to why pre-puberty adolescents should not be weight training.
Weight (resistance) training, or more appropriately, strength development, comes in 2 forms; the increase of muscle mass and/or density as well as maturing of the nervous system. Helping to mature the nervous system moves along the process of myelination or insulation of nerve fibers to allow faster conductivity of the electrical impulses.
There is an article published in "Pediatrics" titled Strength Training by Children and Adolescents
“In addition to the obvious goal of getting stronger, strength-training programs may be undertaken to try to improve sports performance and prevent injuries, rehabilitate injuries, and/or enhance long-term health.”
“Similar to other physical activity, strength training has been shown to have a beneficial effect on several measurable health indices, such as cardiovascular fitness, body composition, bone mineral density, blood lipid profiles, and mental health.”
“Multiple studies have shown that strength training, with proper technique and strict supervision, can increased strength in pre-adolescents and adolescents…In pre-adolescents, proper resistance training can enhance strength without concomitant muscle hypertrophy. Such gains in strength can be attributed to a neurologic mechanism whereby training increases the number of motor neurons that are ‘recruited’ to fire with each muscle contraction. This mechanism accounts for the increase in strength in populations with low androgen concentrations, including female individuals and pre-adolescent boys. In contrast, strength training augments the muscle growth that normally occurs with puberty in boys and girls by actual muscle hypertrophy.”
And most importantly...
“Appropriate strength-training programs have no apparent adverse effect on linear growth, growth plates, or the cardiovascular system.”
There are quite a number of studies involving prepubescent kids. One group was exposed to strength training before puberty and others were not. Then at the age of 13-14 all the subjects were put into a general strength-training program. On average, the group that had been exposed to strength training gained muscle and strength at a greater rate than the non-exposed group. They theorized there was a “priming of the pump” effect within the muscles and nervous system in the kids that had been exposed to physical training. The gains can be attributed to the hormones released during puberty; the body is flooded with testosterone and those kids that had the “priming of the pump” effect made greater physical advances, as there body was more able to utilize/maximize the hormone release.
So, this begs the question, WHAT SHOULD training look like in pre-puberty?
Strength training for kids should consist of skills like, coordination, stability, range of motion, agility, kinesthetic awareness, flexibility and balance. This should include large muscle groups that utilize body weight movements (body weight movements are still weighted/resistive) and free weights with light, manageable loads in big compound movements. Things like Olympic weightlifting, gymnastics and plyometric movements. If these exercises and movement patterns are taught at a young age the athlete will have a greater advantage in technique as they progress in age and strength, no different than teaching tumbling, or martial arts movements where muscle memory and neural endurance are super important. Also, as noted above in the Pediatrics article, strength training in children has been shown to promote increased bone mineral density. Gymnastics movements teach strength and explosiveness in the trunk, shoulders and limbs that is not found anywhere else. Plyometric movements have great carry over to speed, aiding in the Olympic movements and vice versa.
TL;DR version - I totally disagree