Literature available on resistance training for ages 9-14?

Does anyone know of any literature available that discourages resistant training in younger age groups? Two of my sons are swimming for a local club and the coach wants my 10 year old to use a drag suit and paddles. Before I confront the coach on this issue I need some literature that suggests resistant training in pre-puberty individuals is misquided. Does anyone know of any articles suggesting younger age groups should use more technique related drills instead of power driven sets? I need evidence against this practice to show the coach and other parents. My opinion isn't enough. I have a couple of Go Swim articles and articles off of the USA Swimming site, but I feel I need more. Thanks for any response. Your sons' coach is an idiot. Look at most health and fitness book for kids or PE training books for potential teachers.

Does anyone know of any literature available that discourages resistant training in younger age groups? Two of my sons are swimming for a local club and the coach wants my 10 year old to use a drag suit and paddles. Before I confront the coach on this issue I need some literature that suggests resistant training in pre-puberty individuals is misquided. Does anyone know of any articles suggesting younger age groups should use more technique related drills instead of power driven sets? I need evidence against this practice to show the coach and other parents. My opinion isn't enough. I have a couple of Go Swim articles and articles off of the USA Swimming site, but I feel I need more. Thanks for any response. Your sons' coach is an idiot. Look at most health and fitness book for kids or PE training books for potential teachers.