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The myth of body type classification.

Body type myths

There’s a common belief that we fall into one of 3 body type categories; we're either ectomorph, mesomorph or endomorph. While it’s true that we each tend towards a particular body type, individual differences actually play a far more important role in determining our body types, as training specialist Florian Nock explains.

In the 1940s, American psychologist William Herbert Sheldon developed a classification system for the human body, in which he claimed that all people were either ectomorphs, mesomorphs or endomorphs.

Ectomorphs were defined as slender, lean and best suited to endurance activities. In contrast, endomorphs were seen as strong, larger and able to gain muscle quickly. Finally, mesomorphs were a combination of both; naturally athletic, high-responders and equipped to lose fat and gain muscle.

Within just a few years, psychologists started to discredit this theory. Nevertheless, this classification system is still seen as the benchmark by many in the fitness community.

Ectomorph, mesomorph, endomorph: The problems of putting people in boxes

The first problem is that this system is an oversimplification; we can't classify body types into just three classes. Every one of the seven billion people on earth has a slightly different body type.

The second issue is that this classification system isn’t fixed. We change and evolve, so many of the "gifted" mesomorph athletes were formerly endomorphs or ectomorphs.

Lastly, by restricting us to fixed types, it limits our perception of what we can achieve. Someone considered an ectomorph might think that it’s impossible for them to ever gain strength, so they never even bother trying. An endomorph could believe that they can't lose weight, when, with a few lifestyle changes, there’s no reason why they couldn’t.

Where do our individual differences come from?

Genetics play a considerable role in determining individual differences. At a macro level, some characteristics are influenced by our DNA and ethnic heritage. We also inherit traits from our relatives and, at an individual level, we all have unique characteristics such as the proportion of muscle fiber types and the length of our limbs. These characteristics combine to form a very individual body type.

Training can also affect individual differences. The impressively lean bodies of long-distance runners and the powerful muscles of weightlifters were not genetically determined, but forged on the training ground. Our individual differences are affected by our training method, frequency, and intensity. With endurance activities like running and HIIT, you train the slow twitch muscle fibers and can develop some “ectomorphic” traits such as low body fat and lean muscles. During strength training, you build your fast-twitch and intermediate fibers' muscle which increases muscle size.

Finally your lifestyle plays a considerable role. By being active and looking after your body, you improve its ability to gain muscle and lose fat.

Let’s recap:

You define your body traits. A combination of all of these factors determines our body type, not an anachronistic and limited classification system. Genetics is only one part of the equation; your current body type characteristics are an image of what you did until today; it's up to you to define and work on your next body.

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