There are two forms of scleroderma: localized scleroderma (primarily affects the skin, most common form found in children) and systemic sclerosis (a chronic, degenerative disease rarely seen in children). Linear scleroderma is a progressive loss of subcutaneous fat with pigment changes in the skin.
We assume that the person described here starts the work period eagerly, using stored glycogen at the beginning of the work session. Muscle glycogen remains is the major source of energy during the first half-hour. After this period we see that fatty acids and blood glucose takes over as important energy sources.
A Discovery Health answered. Muscles have big reserves of glycogen, a complex carbohydrate. Glycogen is a chain of glucose molecules; the glycogen is split into glucose by cells. Then cells use anaerobic metabolism (meaning without oxygen) to make ATP. (Adenosine triphosphate, or ATP, is the way your body uses biochemicals to store and use energy.) A byproduct from the glucose is called lactic acid.