If your eyes glazed over in health class when your teacher started talking “somatotypes,” we’re here to refresh your memory. Your muscle and fat distribution throughout your body frame determines your somatotype, which is also referred to as your body type.

There are three of these general physiques: ectomorphs, mesomorphs and endomorphs.

QUIZ: What’s Your Body Type?

History of Somatotypes

The somatotype theory dates back to the 1940s, when psychologist Dr. William Sheldon derived the names ectomorph, mesomorph and endomorph from the layers of embryo tissue (ecto-, meso- and endoderm) that develop into parts of the body. In his original theory, Dr. Sheldon drew correlations between body type and temperament, which (no surprise here) he could never prove.

For example, Dr. Sheldon claimed that ectomorphs (who have the tendency to be skinny) are artistic and introverted, while endomorphs (who have more fat on their frame) are tolerant and more extroverted. While it’s true that mesomorphs have a more athletic build, this doesn’t mean they’re more energetic and aggressive, as Dr. Sheldon proposed.

Patrick Lane/ScEyence StudiosAn ectomorph somatotype


Ectomorphs have a delicate frame without much extra fat. Their limbs are long, and their muscles, lean. They tend to be slender.

Health Implication: A high metabolism means ectomorphs are hungry frequently. Choosing nutritional foods to satisfy this urge is the key to keeping healthy. Ectomorphs could also afford to bulk up more muscle.

Celebrity Examples: “Twiggy” actresses Keira Knightley and Courtney Cox, Paris Hilton and you guessed it—60s model icon, Twiggy herself.

Best Exercise: Walking lunges or squats help build muscle. It tones the legs, and like we said—ectomorphs could bulk up a bit!

Patrick Lane/ScEyence StudiosA mesomorph somatotype


Mesomorphs are muscular with a medium frame. They’re the “athletic” types: solid torso and shoulders, with a narrower waist.

Health Implication: Typically, mesomorphs can bulk up easily—with both muscle and fat. But they can also lose that fat just as easily. As mesomorphs age, they can keep their bodies toned with regular cardio and weight training.

Celebrity Examples: Michelle Obama to Madonna and fitness all-star Jillian Michaels.

Best Exercise: Yoga stretches muscles in a soothing manner. This is especially a great break from strength training. Though seemingly less intense, it’s still a complete exercise!

Patrick Lane/ScEyence StudiosAn endomorph somatotype


Most women are endomorphs—feminine and soft. This physique is rounder and they can gain fat and muscle easily. They’re fortunate to have stronger legs.

Health Implication: The metabolism of endomorphs might be slower. Even if it comes less naturally for this body type, they can still burn fat and build muscle.

Celebrity Examples: The “knockouts” of our era and eras past are often endomorphs. Think Christina Hendricks of “Mad Men” fame, and the real 1950s gal, Marilyn Monroe. Kate Winslet and actress/singer Jennifer Hudson are also endomorphs.

Best Exercise: Pilates works the lats, legs and glutes—three of the biggest muscles in the body. Start slow and build up support and balance. In no time, Pilates moves will burn fat, big time.