“Burning the candle at both ends” means using so much time and energy that you wear yourself out. People use it when someone is staying up late, getting up early, and trying to do too much at once.
The image is easy to understand. If a candle is lit at both ends, it burns faster and will not last as long. In the same way, a person who keeps pushing hard from both sides of the day can become tired, stressed, or ill.
This expression has been used in English for a long time, and the candle image is the key to its meaning. You do not need to picture a real candle in modern use, but that picture explains why the idiom suggests waste, strain, and a shorter supply of energy.
- She has been burning the candle at both ends since she started her new job.
- If you keep burning the candle at both ends, you will feel it by Friday.
It often has a warning tone. It suggests that hard work is not the only issue. The problem is doing too much without enough rest.