noun
running out of energy; running out of strength
Used when physical or mental energy is depleted, often in sports, work, or daily life contexts.
マラソンの最後でエネルギー切れを起こした。
I ran out of energy at the end of the marathon.
長時間の勉強でエネルギー切れだ。
I'm out of energy from studying for a long time.