At the end of races i usually can't stand up, legs full of lactic etc. this can be anywhere from 1500-8k. It's nothing serious; i never throw up, but i just feel completely dead for at least a minute before i can walk and get back to normal.
Is this a usual result of pushing yourself hard? am i just being a pusy? I find i try to give it everything in the last few hundred metres of a race; my pacing isn't great.