Peter's Principles - Exercise
Muscles and Fat
Can your muscle turn to fat if you stop working out? The answer is no. Although it may appear as if that is the case, muscles and fat are two totally different physiological entities.
So what happens when you stop working out? Your muscles will shrink. It's called muscle atrophy. As the muscle shrinks, it takes up less space and fat cells move in to take its place, giving you a less toned, flabby appearance. You can reshape those shrunken muscles though, by working out again.
Remember, what you don't use you lose; and that goes for muscles, too.