In Reply to: the three types body posted by Rob on May 24, 19100 at 10:35:00:
I believe you are thinking of the three somatotypes; ectomorph, mesomorph, and endomorph.
Classis ectomorphs are taller, and have more slender frames. They tend to have a higher percentage of slow-twitch (endurance) muscle fibers. They also have a harder time adding muscle, but seem to be able to eat anything without gaining fat.
Endormorphs are stockier, have a higher bodyfat, and tend to have a higher percentage of fast-twitch (sprint) muscle fiber. They can add muscle quickly, but also can gain fat very easily, and have trouble losing it.
Mesomorphs are considered to be the happy medium- muscular, but lean.
Most people are somewhere on a sliding scale between ecto and endo. By knowing what your body's natural tendencies are, you can tailor your diet and exercise programs to go with the flow, instead of fighting it.