Quote Originally Posted by Lint
Don't get me wrong, someone who practices MMA would have the advantage in a punch up since you are trained to take and deliver punishment but as soon as weapons or multiple opponents are involved (typical in a street fight) it becomes a whole new ball game.
Traditional arts also have a lot of conditioning exercises for building endurance such as:
* jabbing palms and fingers at a gravel-filled bag (known as Iron Palm or Iron Hand)
* bumping limbs against teach other (known as "knocking")
* gradual striking of parts of the body

Here are some videos showing conditioning exercises to harden parts of the body:
http://www.youtube.com/watch?v=8fKSoB2GByM
http://www.youtube.com/watch?v=poN-ExZRQxw
http://www.youtube.com/watch?v=im9NzBciths