burn the candle at both ends

Example: “Working all day and studying all night, she's burning the candle at both ends.”

Origin: Arrived in English as a translation and originally meant something quite different from what it means now. Randle Cotgrave's French-English dictionary of 1611 rendered a French expression about burning the candle at both ends, and in French it described a person wasting money and resources — a candle lit at both ends is consumed twice as fast for no additional light, which made it a figure for extravagance rather than exhaustion. The modern sense of rising early and staying up late developed later in English, helped by the fact that candles were the reason the working day had two ends worth burning at all. The image was revived for a twentieth-century audience by Edna St. Vincent Millay's much-quoted poem of 1920.