Can Knowing Your Somatotype Help You Change Your Body Composition?

May 10, 2017

Are you one of those people who exercises regularly, but can’t understand why you don’t look like that person next to you on the treadmill or weight bench? What about that friend who seems able to eat just about anything and never looks like they gain an ounce? Or maybe you know someone who has an outstanding athletic physique without even trying.

We are often quick to attribute these differences to the mysteries of somatotypes, or different body shapes. However, we rarely go beyond the basic body classifications to explore how our body types differ, such as how these different body types respond to diet and exercise and how we can work with our body types to effectively change or optimize our body composition.

Let’s take a look at the different somatotypes and see how when you identify your body type, you’re able to understand your genetic predisposition and can better make the right decisions to reach your specific body composition goal.

The Three Somatotypes

A somatotype is defined as a “quantitative overall appraisal of the present shape and composition of the human body.” Classifying different body types based on physique provides three generalized divisions of body types: endomorph, mesomorph, and ectomorph. As with anything, it’s rare for someone to fall entirely into one category. You might show qualities of more than one group, such as an ecto-endomorph or a endo-ectomorph.

There are countless articles about how having a general idea of where you fit on the somatotype scale can help give you the knowledge you need to make informed decisions in your quest to change your body composition. However, before we tackle these potentially faulty claims, let’s take a quick look at each of the 3 general structures of body types:

The Shapes


That super skinny friend of yours that often gets called a “stick” falls primarily into the category of an ectomorph. Naturally lean with a tendency towards long limbs, ectomorphs typically possess that slender look no matter what type of diet they consume. A lot of runners and swimmers are ectomorphs. However, although they may have a decent amount of muscle, due to their long limb-length, they may appear visually to have lesser muscle development. Similarly, body fat also seems to get hidden by their long, slender figure - meaning they seem to get away with a few extra pounds of fat. Because of this, ectomorphs can have the tendency to fall into the classification of skinny fat.


Mesomorphs are the seemingly natural athletes out of the three somatotypes. Their physiology tends to include narrow hips, wide back, and larger frame that contributes to an often muscular appearance. Many professional fighters, tennis and basketball players fall into this group.


Endomorphs are the larger structured body types with both wide hips and shoulders but shorter arms and legs. Think rugby props, football linebackers, and powerlifters. Endomorphic body-types are even considered to be a contributing factor in race performance in Ironman athletes.

The Composition

Recall the definition of somatotypes as having both a shape and composition component. While your shape may be set from the start, your body composition is not set in stone. So what are the general body compositions for these different somatotypes?

Ectomorphs look lean and often they do tend to get placed into the category of endurance-type athlete. People with these body types seem to struggle with gaining weight and altering their body composition in such a way that reflects an upward swing in lean muscle mass. Their efforts in the gym may seem to have little effect visually, even causing frustration when trying to initiate a change.

Mesomorphs, on the other hand, have a larger frame that lends to the appearance of a body composition with a high percentage of lean muscle mass and a lower body fat percentage. The result is a more athletic, muscular look.

Endomorphs tend to have shorter, rounder frames, with the appearance of a large amount of both muscle and fat mass. However, due to their stockier features, body fat stored by these individuals tend to be more readily noticeable compared to the other body structures.

Now that we have a better idea of what these three somatotypes look like, let’s see what this really means for your body composition goals and whether or not you can make a difference despite your genetics.

Nature vs. Nurture

Considering somatotypes and body composition often leads to the question: Am I genetically trapped in this body type or can I change it? Numerous studies have investigated the hereditary implications of body composition and the effect of genetics versus environmental factors. Let’s take a look at what they’ve found.

We know that we inherit our genes from our parents. Unsurprisingly, the general consensus is that somatotype has no impact on spousal relationships. In other words, like doesn't necessarily attract like when it comes to somatotype. The partnerships between somatotypes are varied, making for an interesting discussion point when looking at the somatotypes of their offspring. Studies do show a genetic connection between parents and children (nature)-- also reflected in similarities amongst siblings-- with the maternal genes having a more significant impact in many cases.

So genetics do play a role in somatotype, but external factors have an effect as well.

Your diet and exercise both affect your overall body composition and can contribute to that slender or stocky look. There’s certainly a link between diet and body composition, where a diet (or lack thereof) can either promote or hinder your body composition goals. Similarly, your appearance will also greatly depend on the type of training you engage in and whether your goal is to build strength, size, or muscular endurance.

What does this tell us?

In a nutshell, while your body size may be somewhat set in stone, your body composition is not.

Breaking Out of the Mold

It’s important to remember that somatotypes describe different body types in order to provide general guidelines for body composition decision making. Remember, somatotypes are defined as a “quantitative overall appraisal of the present shape and composition of the human body.” While you may be genetically predisposed to have a certain body structure, your lifestyle can impact your body composition and cause your somatotype to change.

Let’s look at the example of the ectomorph. Ectomorphs have been implicated to be better at aerobic exercises like running or swimming. Intuitively, this makes sense. Having longer limbs helps increase stride length and a lower overall body fat percentage helps reduce resistance caused by excess body fat. Races have actually introduced the concept of "Clydesdale or Athena" runners since lower weight has been attributed to better running performance in marathons. Mesomorphs and endomorphs, on the other hand, may possess shorter limb length that may allow them to engage in more power and strength building activities, contributing to the image of these body types having greater musculature.

Now, let’s say an ectomorph wanted to become a powerlifter and achieve a larger figure, breaking out of his ectomorph shell.  Would he be condemned to the life of an ectomorph or can he still achieve one of the other body types?

Think about it this way: If an ectomorph ate cheeseburgers and milkshakes all day and lifted weights like a powerlifter, would he always look like an ectomorph or would his body shape eventually become more mesomorphic, or even endomorphic?

The point is, just because you fall into a certain somatotype, doesn’t always mean you’re stuck in what your body type ‘should’ excel at. Take volleyball for example: A study looking at somatotype in elite volleyball players found that players in various positions had different somatotypes.

Furthermore, your somatotype doesn’t limit what you can do to change your body composition. A study conducted on weightlifters found that there were athletes from all body types scattered throughout the participants. So even if your genetics play a large role in predicting your body frame, you can still engage in the types of activities you enjoy to ensure your genetics don’t decide your overall body composition.

How Can This Information Help You Change Your Body Composition?

Lots of factors can prevent you from changing your body composition, but your shape doesn’t tell you what body composition you have to have. Knowing your somatotype can allow you to work with your body to make changes, rather than working against it and being constantly frustrated by your lack of success.

Pick a sport that best suits your interests and abilities (but remember, you don’t have to be able to dunk to play basketball). Also, just because you have the body type and you like to play basketball, doesn’t mean you will look just like the basketball players you see on TV.

Many NBA players start with an ectomorphic frame due to their long torso and limb lengths in conjunction with their slender figure. With years of full-body strength training and conditioning, they shift their somatotype to a hybrid ecto-mesomorphic body type that makes them ideal bodies for the sport of basketball.

So remember, your body shape can change. Which brings up another important point - monitoring those changes in the long run. As a mesomorph, you may be cheering at your good fortune for having a naturally athletic-looking body, or as an ectomorph you may enjoy having that long, slender frame.

But beware: like anyone else, you have to take care to maintain your body composition in the long run. Despite your current body shape and stature, you’re still at risk of sarcopenia (age-related muscle degradation) or fat accumulation due to poor diet or lack of physical activity.

Relying on the perks of your somatotype isn’t a long-term strategy for health and longevity. Continued training, even simply once or twice a week at moderate intensity, can help prevent muscle loss related to aging and maintain an optimal body composition.

The More You Know

Knowing your somatotype can also be helpful if you’re someone who has struggled to find a form of exercise that complements your physiology. You may be able to develop an exercise routine that feels more natural and easier to commit to if you consider your body type. However, don’t let your current body composition stop you from doing something you’re interested in, just because it’s not a perfect fit. While certain body types may correlate with athleticism, there’s no specific gene that determines whether or not someone will become an elite athlete.

In conclusion, having a general idea of your somatotype and knowing how your body works can help you make the changes required to alter your body composition, but testing your body composition and tracking your changes is the most effective way to achieve your body composition goals.

There is no one-size-fits-all solution when it comes to body composition. We come in all shapes and sizes, and discovering what works best with your body will help you take the necessary steps to achieving your body composition goals.


Nikita Ross is a Precision Nutrition certified wellness coach and professional fitness writer. She believes that lifting both barbells and books is the key to self-improvement.