I haven't yet found an english word that can do the same duty as the Japanese phrase, "yake-kuso". The two roots of this phrase are yaku, a verb meaning to burn/fry, as in yakisoba (fried soba noodles) or sukiyaki (which literally translated means 'desires/likes/preferences, fried'), and kuso, which is the Japanese equivalent of the word shit. Together as yake-kuso, they are used to describe the state or state-of-mind which occurs when one hits one's second wind in a seemingly impossible situation. I have heard friends exclaim "Ah, Yake-kuso ja!" when they slap-happily continue to plug away at something tho they feel that all hope is lost. Nobody I asked was able to come up with an etymology for the phrase, but I have a theory: it could be that, at the point where one feels all is lost but is nonetheless not allowed to give up, that there is nothing left to burn as fuel for their effort but shit. Nasty? Perhaps, but it suits.