Somatotype - What Endomorph, Ectomorph
and Mesomorph mean for Diet and Exercise?


The term originates from the study of Somatoytpes or "Somatotypology." Somatotyping is therefore a means for describing and assessing the human body on the basis of three body shapes and compositions.

Normally a three-digit number or rating is used to express "Mesomorphy", "Endomorphy" and "Ectomorphy", as exemplified further down.

A brief background

The methodology of Somatotyping has evolved from attempts to classify the human physique or figure in relation to the 3 main elements of Embryogenesis (based on the three tissue layers "Endoderm", "Mesoderm" and "Ectoderm"). This was proposed by the Constitutional Psychology theories of William Sheldon during the 1940’s, whereby he associated human body types with certain temperaments.

Sheldon's Somatotype conclusions were based mostly on interviews conducted over an extended period of time, more in the role of Behavioral Psychologist than Anatomist or Physiologist. Hence, the data gathered has been deemed more suggestive than all-conclusive.

Psychological profiling based on anatomical features is today not accepted as valid, however, several aspects of Sheldon's theories have held the interest and following of a string of colleagues and researches, some of whom have made significant propositions and modifications to his work.

Somatotyping methodology has drawn criticism from far and wide as being too subjective and presumptuous, yet it remains the single most accepted means of determining and classifying body shapes.

The complexities of Somatotyping

If you take a closer look and get drawn into the nuts and bolts of this topic as I have, you will note that there has been extensive research by numerous contributors to the methodology. After Sheldon’s initial works, among which the likes of contributors like Parnell, Heath and Carter, and later Rempel expanded on former studies and attempted to simplify the methods for assessment and render calculations more accurate.

However, to stick to the point of this Site, let's end off this paragraph by taking note that the most commonly accepted standard today is the Heath-Carter method. It makes assessments and determinations by obtaining information from comparative body measurements (anthropometry) or photographic data, or a combination of the two sources.


Our bodies primarily reflect our genetic predispositions and to an extent show the effects of certain external factors, whose degree of impact is under our individual control.

So what does this mean in plainer English?

It means that we are born with a predetermined genetic makeup which dictates our unique body shape and physiological tendencies. In addition, our chosen lifestyles, or more specifically "what" and "how" we eat, as well as our physical activities, can influence our natural inclinations and appearance (these are discussed on the respective pages linking from the 3 body types below).

So, based on Somatotypology, the different body types are generally classified into 3 categories*, known as:

As shown in the image below, Sheldon viewed each somatotype as possessing elements of the other, to which he assigned a 3-digit number on a continuum ranging from 1 to 7. The first digit corresponded to the degree of roundness or "endomorphy", the second to the extent of muscularity or "mesomorphy", and the third to the stringiness or "ectomorphy."

Accordingly, a person with extreme muscular tendencies was classified by the archetypical number 171. Individuals displaying rounder Endomorph tendencies would be classified as 771, while those showing extreme Ectomorph characteristics would be classified by the number 117.

As mentioned, subsequent research and modifications of the methodology, most notably by Heath and Carter, have allowed it to evolve significantly from Sheldon’s times. In the 2-D "somatocharts" (exemplified below), Carter and Heath (1990, pp. 389-406) show the layout of the components resembling those in Sheldon’s "cluster charts", however numbers can be rounded off to the nearest half-unit. Components can range from a rating of ½ to t 7½, or higher. A three-digit rating somatoplots on a two-dimensional somatochart using horizontal X and vertical Y coordinates (or axes).

Heath Carter Somatochart 1990, Somatotype, Mesomorph, Endomorph, Ectomorph, health related fitness

It should be noted that certain somatotype ratings which are high in endomorphy and/or mesomorphy, cannot also be high in ectomorphy. By the same token, individuals showing high ectomorphy will not possess high endomorphy and/or mesomorphy. Low endomorphy and mesomorphy will naturally be high in ectomorphy.

Although most of us reflect a dominant somatotype in our anatomy, we each possess qualities of the other 2. The average individual is deemed to stand in the central region of the somatotype triangle (below), somewhere between 333 and 444.

Somatotypes, Body types, Mesomorph, Endomorph, Ectomorph

In certain cases, 2 somatotypes can be reflected in an individual's anatomy and physiology, with minimal presence of the third type. In my example, as a person of average height, relatively large bone structure and reasonable muscle bulk with moderately fast metabolism, I estimate my rating as 4-2-4. I primarily reflect the tendencies of the 2 somatotypes Endomorph and Ectomorph, with a small presence of mesomorphy. I am therefore what you would call an Endo-Ectomorph.


The different somatotypes are not only distinguishable by the length, shape and density of the bones, muscles and lengths of the tendons, but also by individual metabolic tendencies and physiological constitutions.

Ectomorphs usually have narrower bones and a linear stature. Endomorphs are normally burlier with larger bone structures and have higher fat and muscle quantities than Ectomorphs. The Mesomorph is the benchmark body that the other two are usually compared to.

Mesomorphs are genetically gifted individuals and have the tendency to carry minimal body fat while sporting a pronounced musculature. Although "true" mesomorphy by the other two somatotypes can never be achieved, muscle can be built through appropriate strength training and fat can be shed and kept off by physical exercise and good eating habits.


It is important to bear in mind that the respective somatotypes predispose different degrees of potential and response to the "training effect" of physical exercise, and are thus important considerations for planning exercise and nutrition intake. This means that we should individually determine what our own tendencies are and work with them and their advantages.

Although a Mesomorph will do better in competitive athletics due to a more muscular genetic makeup, it does not mean that an Endomorph or Ectomorph cannot be successful in athletic performance. It does mean though that the latter two will need to adapt their exercise techniques and eating plans to afford the necessary lean mass gains to allow them to compete.


Even if one's genetic traits are carefully considered, it is not scientifically possible to gauge exactly what the influence of genetic inheritance is on levels of overall fitness. Somatotypology should be seen more as a guideline or indicator for considerations and expectations where exercise programming and nutrition plans are concerned.

The best indicators come from one's own results, which can be observed and measured by planning and recording periodic progress. With measured results, one can adjust and revise goals and objectives realistically.


The different somatotype factors and characteristics play an integral role in response and adaptation to exercise (both aerobic and anaerobic). Working realistically with genetic gifts and/or drawbacks will make you a more efficient trainee in terms of results anticipated and achieved.

In brief, those of us with longer muscles (and usually a higher ratio of fast-twitch muscle fibers) and faster metabolisms will find it easier to build and shape our bodies due to the more mesomorphic genes we possess. Exercisers with this body type tendency may find it easier than others to lose body fat and gain lean mass.

On the other hand, Ectomorphs usually find it a little easier to shed the pounds but need more effort to build muscle, whereas Endomorphs find it a little trickier to lose weight and need to stay true to their cardiovascular exercise and nutrition plans. However, one should not fret about being an Ectomorph rather than an Endomorph or Mesomorph, as there is no one body-perfect.


Television and Web infomercials perpetually exploit their products and services under the guise that they deliver jaw-dropping results – to anyone, no matter what. These ads propagate workout programs, diets and performance supplements as being able to yield formidable results in record time. They often talk, not only in terms of weeks or days, some flaunt their products claiming that they will bring you "overnight results, while you sleep."

As I have mentioned already in this Site, inform yourself about what you're in for when taking up physical exercise and/or adjusting your diet. Ensure that you get yourself checked by a qualified practitioner (if you're a first-time exerciser) and proceed prudently. Do not just try anything that predicts immediate success.


Unfortunately not, your somatotype is a fixed combination of musculature, bone structure and density, but a healthy lifestyle will do wonders to bring out your potential. Any "body" left to the devices of a careless lifestyle or poor eating habits, regardless of the somatotype, will certainly show the neglect.

The good news though, is that your body can be altered with physical exercise and good eating habits. As Charles Hix puts it in his honest and enlightening book Working Out, "you can’t have any body you want, but you can have a damn good one."


As with the Sensible Physical Fitness Program, one should keep in mind that is naïve and unrealistic to approach physical exercise and nutrition blindly and expect fitness gains regardless, for example packing on huge quantities of muscle in a matter of weeks.

Rather, one needs to consider vital factors like individual differences in health condition, genetic predisposition and muscle-building potential, to name a few. Any one-size-fits-all concept risks being flawed from the outset. Once underway with a workout routine like the Sensible Physical Fitness Program or any other for that matter, you’ll be in the best position to know how your body is fairing and what adjustments, if any, you need to consider as you work towards shaping up to look your best.

Although it is useful to classify the 3 main body shapes or types with respect to somatotype methodologies, it should not be viewed as the primary consideration before undertaking exercise or devising a training program. Pigeon-holing yourself may offset the very necessary personal conviction you need for successful training and/or fulfilling a body transformation program.

Also refer to the somatotype pages in this Site which elaborate the individual characteristics of each one (or two, if you happen to reflect more than one somatotype). It will be useful for you to see where your body type places you, and what specific considerations you need to make, other than the general ones discussed on this page.

*The individual Somatotype pages provide more detail on their respective tendencies and training considerations. However, the information on those pages should not be construed as hard-and-fast fact or fitness advice. Although humans generally show characteristics of one particular Somatotype, the degree to which an individual can be categorized as one Somatotype or another, or a combination of two or three Somatotypes, is not possible in any conclusive or scientific manner. Somatotypology is approximative. Every human individual possesses innate physical and physiological predispositions of all 3 Somatotypes.

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