Which body type is typically long and narrow with difficulty gaining weight?

The body type characterized as long and narrow, with difficulty gaining weight, is indeed the ectomorph. Ectomorphs typically have a slender build, with narrow shoulders and hips, and they often find it challenging to put on muscle mass or increase body fat. This is primarily due to a fast metabolism which means that their bodies burn calories at a quicker rate than other body types.

Ectomorphs also tend to have long limbs and minimal body fat, which can contribute to their overall lean appearance. Their unique metabolic profile necessitates a specific approach to nutrition and training if they aim to gain weight or muscle mass, often requiring higher calorie intake and resistance training.

In contrast, mesomorphs generally have a more muscular and stocky build and can easily gain muscle, while endomorphs tend to have a rounder physique with a propensity to hold onto body fat. Understanding these distinctions is crucial for tailoring fitness programs and nutritional advice to meet individual needs effectively.