I would say he's not to young to start learning the basic excercises and how to lift weights properly. Also I think the most important thing would be a good knowledge of nutrition and diet. A good diet is something that can stay with him the rest of his life. I started lifting when I was 13. Just a home gym with a Sears 150lb. weight set. Also, if he hasn't gone through puberty, and he is trying to get bigger and pack on the muscle, forget it. He'll have to wait a while
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