It’s true- they can’t.
Why, you ask?! Because muscle and fat are two separate and distinct tissues. There is no physical capability to change from one to the other.
With muscles, you either “use it, or lose it!” When you’re not using muscle, it will literally just waste away. When that happens, it’s called atrophy.
Here’s a good example for you:
Think about someone who wears a cast on a broken leg/ arm. When the cast has been removed, the leg or arm that’s been unused will be smaller than they were before. If it was true that muscle turned to fat from not being used, you’d see a fatter leg or arm after removing the cast- that isn’t the case, though.
With that being said, don’t let those muscles waste away!
It’s Friday and I hope you all have a wonderful weekend!