Somatotype is a broad, practical framework, not a medical diagnosis — most people are a blend, and your body composition can change with training and nutrition whatever your type.
The three body types
The somatotype model sorts people into three broad builds. Ectomorphs are naturally lean and long-limbed with a fast metabolism, and struggle to gain muscle or fat. Mesomorphs are athletic and muscular, gain muscle easily and respond quickly to training. Endomorphs have a larger, softer frame and put on both muscle and fat readily, often with a slower metabolism. Almost nobody is a pure type — most people are a dominant type with a secondary one, like a meso-endomorph, which is why this quiz reports a percentage for each.
Why your type is a starting point, not a limit
Your frame — bone structure and limb length — is largely set, but your body composition is very much in your hands. An endomorph can get lean and an ectomorph can build real muscle; it just means each type benefits from a slightly different strategy. Knowing your tendency helps you set realistic expectations and pick the training and eating approach that works with your body rather than against it. Use the guidance above as a default, then let your own results steer the fine-tuning.
Putting it to work
Whatever your type, the fundamentals are the same: progressive resistance training, enough protein, and calories matched to your goal. Set your daily energy needs with the TDEE Calculator, dial in protein with the Protein Calculator, and track composition over time with the Body Fat Calculator. Your somatotype mainly tells you where to start and how aggressively to push calories up or down.