Many people has this misconception – muscle will turn into fat when they stop doing weight training. In fact, many women are avoiding pumping iron because of this belief.Banana will not turn into papaya. Lead will not be gold. Muscle will not turn into fat and vice versa.
Muscle and fat are both cells. Human body also has other types of cells. The type of muscle we can see is the so called skeletal muscle whereas a fat cell store fats which they get it from the blood stream.
When you stop lifting weight, the muscles will get smaller. You still have the same amount of muscle cells but they have got smaller. At this stage, if you continue to eat the same amount of food, the existing fat cells will now expand. However, the muscles are still there. In other words, as muscles shrink because of inactivity, fat has filled up the space where the muscles used to be, giving a false impression that the muscles have become fat. To make things worse, with less muscle, the metabolism is getting lower making fat is easier to be accumulated.
In short, muscle is muscle and it is not fat; fat is fat and it will not become muscle. Hopefully, this “urban legend” has been cleared after you read it.