In terms of body composition, what does an ectomorph typically represent?

An ectomorph typically represents a body type characterized by a low body fat percentage and a thin frame. This somatotype is often associated with individuals who have a slender build, long limbs, and narrow shoulders. Ectomorphs generally find it challenging to gain weight, whether it's in the form of fat or muscle mass, due to their fast metabolism. This body type reflects a lean appearance with a lower propensity for storing body fat, which is why the option accurately aligns with the defining characteristics of an ectomorph.

The other options do not accurately describe an ectomorph. For instance, a high body fat percentage characterizes an endomorph, while a muscular build is more reflective of a mesomorph. A balanced physique could describe a combination of body types, but it does not specifically apply to the ectomorphic classification. Thus, identifying an ectomorph as having low body fat with a thin frame is a precise way to define this body type.