system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why do muscles become less strong?

So when you workout, you're making like micro tears in the muscles, which then heal stronger. Thus the muscle becomes stronger 

But shouldn't that muscle just stay strong? Like if you workout less but you're still using that muscle, why is it becoming less strong?
gpt
>But shouldn't that muscle just stay strong? Like if you workout less but you're still using that muscle, why is it becoming less strong?  
  
Muscle tissue is very expensive to maintain. Your body doesn't like maintaining things it doesn't need since that's valuable energy that could be used for survival. Accordingly, muscles that don't get used are disassembled and used for sustenance.