issue of the year for me, when do you call a day quits, I can think of at least three or four days where I kept on going after I was pretty hurt (bruised/cracked ribs, thumbs, split lips, pulled groin), and I paid the price most of those ones afterwards...
worst was ribs on 270ing into a flat rail, which I had been stomping the hell out of for a morning. then proceeded to biff chest first, and get up only to self-destruct to near nutting, that ended my day.
but when do you back down from a trick you know you can do? or when do you stop for a day just to avoid hurting yourself...