Add a simile to the given sentence to enhance its clarity.
He was showing signs of fatigue.
He was showing signs of fatigue, like a heavy weight holding him down.
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Add a simile to the given sentence to enhance its clarity.

### Response:
He was showing signs of fatigue, like a heavy weight holding him down.