[QUOTE=Joe W. Namath;4447000]Weightlifting is fine at 13. Just focus on form so he doesnt injure himself. and have him go light for awhile.[/QUOTE]POTY
If he wants to be a good athlete, then lots of reps with light weights. The level of strength a 13 yo can develop through consistent reps of manageable weight is formidable. All that raw power will be available for skill training. I've seen it go the other way and it sucks - kids that bulk up for High School football have obese lives waiting for them.