What body type is primarily defined by muscularity?

The body type that is primarily defined by muscularity is the mesomorph. This classification represents individuals who tend to have a naturally athletic build, characterized by a higher proportion of muscle mass and strength. Mesomorphs often find it easier to gain muscle and maintain a lower body fat percentage compared to other body types. Their physiques are typically described as broad-shouldered and narrow-waisted, which contributes to a powerful and well-proportioned appearance.

On the other hand, endomorphs are generally characterized by rounder body shapes with a tendency to store fat more easily. Ectomorphs are typically lean and slender with narrow frames and struggle to gain weight or muscle. The term "skinny-fat" is not a recognized body type classification but rather describes individuals who may appear thin yet have a higher body fat percentage and lower muscle mass, combining traits from multiple body types without fitting into a distinct category.