When one's resources or energy begin to dwindle, the word "be depleted" may come to mind. However, there are a plethora of synonyms available that can be used to convey this same idea. For example, one could say their reserves have been exhausted, their stockpile has been emptied, or their energy has been drained. Other options include being depleted, being diminished, or being spent. In more formal language, one might use the phrase "running low" or "running out of." Whatever the choice of synonym, the idea remains the same: a state of depletion has been reached, and action is needed to restore what has been lost.