Why do muscle twitch (or twinge)?
Muscle twitch could be related to too much stress, caffeine, poor diet or lack of exercise.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
### Instruction: Why do muscle twitch (or twinge)?
### Input: 
### Response: Muscle twitch could be related to too much stress, caffeine, poor diet or lack of exercise.