Does Muscle Turn To Fat?

Oh, the horror: you work out for months and years, then take a break and next morning you wake up and all that muscle has turned to fat. Can that really happen?

Can Muscle Turn Into Fat?

I didn’t even really know that this was on people’s minds when thinking about working out, but the question has come up again and again, so we better address it.

The answer is nope, muscle does not turn into fat. It’s simply that when you stop working out, your body starts building back your muscle mass. Then, if you keep eating as much as before, you burn less energy and all the unneeded calories end up on you as energy reserves. Yes, “energy reserves” is a nice way of saying you will build up some beautiful bigger fat layers:

So, as said in the video, to not have your “muscles turn into fat” should you have to take a break from working out, simply adjust your daily calories and at least try to throw in a “maintenance” workout here and then. Keeping your muscle mass is easier than getting it and if your body feels at least some of it is still needed, it won’t build all of it back.

But Can You Turn Fat Into Muscle?

While we are at it, let’s also examine the other way around: can you turn fat into muscle? This works only in the sense that you can use body fat as the energy you fuel your workouts with, but the muscles themselves need protein to get bigger. If you were chubby and work out while eating enough to keep your body weight constant,  your muscles would become bigger, but the fat layer covering them would remain as before.

It is possible to lose fat while gaining muscle, but that is an entirely different thing and requires being a bit strict about your nutrition.

Picture courtesy of Warren Brown.