It does not make your body exhausted, it reduces your currently available energy.
Your body stores energy when not needed and releases energy when needed. But needed means your brain thinks you need it.
When you are depressed nothing seems to be important. When nothing important is going on your brain decides it is a good time to rest and save energy.
If something happened to scare you or otherwise think something important was going on, you would have a flood of energy.
Latest Answers