One of the most common fears about weight training for young athletes is that it will damage growth plates. Here is a great quote from a respected sport scientist concerning this issue:
"It has never been shown scientifically or clinically that the periodic, non-chronic imposition of large forces by weight training on the growing body causes damage to the epiphysial [growth] plates. It is extremely misleading to focus on the alleged risks of weight training on children when biomechanical research shows that simple daily activities such as running, jumping, striking or catching can impose far greater forces on the musculoskeletal system than very heavy weight training."
Mel Siff, Ph.D.
FYI: The late Dr. Siff taught biomechanics to postgraduates, applied mechanics to undergraduates, and researched topics in exercise science that I canít begin to spell, much less pronounce. He has a Ph.D. in physiology and a master's in applied mathematics. His doctoral dissertation examined the mechanics of soft tissues, while his master's thesis dealt with how to apply mathematical models to brain waves.