Deplete

SAP

Think of what a tree might do to your energy over time.

"SAP" fits "deplete" because it means to gradually weaken or drain something, like energy or resources. The word also plays on its literal meaning—sap is the fluid inside plants, so draining it weakens the plant, reinforcing the idea of depletion. It’s a concise answer that captures both the action and the result in just three letters.