Hi. I'd like to reccomend Martial Arts as a great way to improve self discipline, strength, lung power, and learn how to defend yourself. I have taken martial arts for almost two and a half years now(I think). I'm one belt below brown, and I can tell you: I'm a lot stronger, better self disciplined, and stronger lung-wise than I was before I started! It's a great thing to do, but don't take it at some karate school that promises you a black belt in six months, or that makes all your goals easy to attain.All in all, karate is a great way to improve lung strength and body strength.