Health Myth: Muscle Can Turn to Fat

Maybe this myth was started by the marketing department of a health club chain. People often worry that once they stop regularly working out, their muscle will become fat. But muscle CANNOT turn into fat, because they’re made of two very different types of cells. People get fat when they stop working out, because they continue to eat the same amount of food, but burn off fewer calories. As a result, their unused muscles grow soft while they simultaneously gain excess body fat. If you stop exercising, you’ll still have the same NUMBER of muscle cells—but each will get thinner. If you continue to eat the same amount of food, *the fat cells, which were already there, will expand. This is the basic weight gain equation:  if your "calories in" are greater than your "calories out," then your fat cells will begin to bloat and gloat. But under no circumstances will your muscle cells morph to fat cells.