Does Muscle Really Convert To Fat When We Stop Exercising ?

Those of us whose gym memberships collected dust last winter or expired months ago may be left with physiques that went from firm to flabby.

So did all those muscles simply melt to fat from more time on the couch and less at the sports club?

That might be the popular explanation, experts say, but it's not exactly true. When people stop exercising and shift into couch potato mode, their muscles begin to shrink, clearing the way for adipose tissue, or fat, to slowly replace them. At the same time, many people who stop exercising often continue to consume the same amount of calories as they took in during their more active days, despite the fact that their energy expenditure is no longer nearly what it once was.

All of this can create the illusion that a lean six-pack and bulging set of biceps turned to fat, but muscle and fat are two distinct tissues that can never convert to the other.

"What happens is that the ratio of fat to muscle has changed, If you have atrophy of the muscle, then other tissue can move in and take its place."