<<< lots of young athletes, (e.g. gymnasts where they start them young and push them hard) have stress fractures of the pars interarticularis, which basically attaches the body of the vertebra to the facet joints - this can lead to forward slippage of the vertebral body in relation to the one below it. >>>[/quote]
This is the trouble with this though. All the research I’ve seen declaring these warnings attempts to extrapolate conclusions about weight training from high impact activities like gymnastics where these types of things are known to occur albeit in fairly extreme cases as well.
I haven’t seen any evidence to indicate that weight training in anything like sane applications is detrimental to even young children. Quite to the contrary many predictable benefits have been identified.
I’m not known to be one who is overly enthused by the fitness and health recommendations of the mainstream scientific communities, but for what it’s worth here’s a piece from the American Academy OF Pediatrics.
On an anecdotal note my daughter has been seriously training for about half a year now (her idea) and has undergone a pronounced growth spurt along with being the strongest, healthiest 11 year old girl I’ve ever seen.
Her strength has gone through the roof in truly eye popping fashion practically by accident. She does eat lots of good food which I’m sure isn’t hurting.