How can a 14 yr old boy get noticable pecs.?

I know this sounds weird but if you have heard of alexander ludwig from race to witch mountain, I would like to find out his workout, because he has the the type of chest muscles that I want. The kind that stick out a little when you have a shirt on. And if this helps I am not at all fat. I think I am as tall as alex. I have abs already but they look weird without chest muscles. Thanks a million.