First and foremost your body is your weapon. If your weapon is dull and stiff it is going to be useless when you need it - kind of like leaving your gun in your sock drawer. You're weapon is your body and it needs to be honed to a razor edge and the only way that's going to happen is if you learn to use it. I'm not talking about maxing out on your bench and biceps curls. I'm talking about learning how to move your body: push-ups, squats, handstands, etc. Getting the feeling behind how the muscles, joints and connective tissue work together to generate power - you can't learn this doing curls and triceps kickbacks - I know you think you can but you can't.
Take a few minutes to check out this article by Paul Wade and see if the information in it could help you move better and maybe live a little longer...