Both of my sons started lifting weights as early as 6 or 7 they are 16 and 13, I started with nothing more than a broom stick to teach tech. These things that say they shouldnt start so young is hog wash, as long as you are giving them the proper instruction and not pushing the weight there is NOTHING wrong with it, Boyd Eply a Nationaly recognized strength coach, who I even talked to about this subject had his own kids start at an early age, said that it can only benifit them if given the proper instruction. Both my sons have benifited greatly because of it, and neither has had their growth stunted or any of the other ol wives tales taht come from lifting to early.