1To exhaust one's strength — to be completely worn out physically or mentally; also used figuratively for losing hope of success.
マラソンの後半で力尽きて、歩かざるを得なかった。
In the latter part of the marathon I ran out of strength and had to walk.
彼は最後まで戦ったが、力尽きて試合に負けた。
He fought until the end but ran out of strength and lost the match.
徹夜での作業により力尽き、机で寝てしまった。
After working all night I exhausted myself and fell asleep at my desk.