Armand Tecco, M.Ed. Endomorphs have a rounder, sometimes pear-shaped figure. However, not all endomorphs have high body-fat counts. An endomorph with average body fat usually has a large bone mass. Bone frame size for all endomorphs typically ranges from medium to large.
Ectomorphs tend to be tall and slender, and look thinner.
Most have delayed or sustained growth periods during which large increases in height are seen in relatively small amounts of time. The long bones of their arms and legs seem to develop more than those of endomorphs and mesomorphs. Ectomorphs don't always have low body-fat counts. In fact, they have just as much potential to put on body fat as endomorphs, but because of their long, thin appearance their excess fat is not always obvious. In general, their muscles are well developed, their shoulders are broad and their waistlines are narrow.