lets just say sport fighting where two people choose to rough each other up...
[as the other situations you could potentially avoid, and that may be the "best training" for physical confrontation - not creating the background scenarios in which these 'confrontations' happen.]
So, the one thing you need is to be able to take a beating/toughen your body. [talking of sport fighting]
You ever seen those monks who can do amazing feats with their bodies because they toughened it up over the years?
Take your hand and hit them as hard as you can and you might be the one walking away with something broken. - Amazing how their bodies have been conditioned.
Ill tell you with the little Thai Boxing experience I have, it hurts being kicked even with pads.
Get hit in the stomach time and time again stings quite a bit... etc.
So you want to sport fight, then toughen your body up... get flexible, get coordinated, etc.
You want to stay out of a fight... learn who you are, "know theyself".
Trust me, from experience, I could have avoided certain situations had my attitude/thoughts been in the right place.
Consider this, you wont always be in prime condition - give you a few years and then you age and its over for the 'brutal sports' and you will have to learn other ways to fend for yourself... and the thought patterns, if you will, is key to be sure.
[sorry, I know its not the hip answer]