boxing is a good thing. kids start it up because they have some grand romantic like notions of what they think boxing is and only then ever continue to do it once they realize and embrace how far from reality that idea is - either that or quit. most get out of it because they never had the idea of a good work ethic and discipline with them to begin with. at an age ilke 5, he is probably still in that romantic stage so you want to just be sure you learn him on the value of discipline and work ethic. that i think is the most important thing to take from boxing, more important than anything else. its a good time to get those things in him before he gets to an age where so many of us lacked it and needed it most.