Ectomorph, Endomorph, And Mesomorph: Does Body Type Training Work?

Your body type doesn’t tell you anything meaningful. Here’s why.

In a world where the concept of ‘nutrigenomics,’ or DNA-based diets, is steadily gaining popularity, it’d seem only natural that you should be adopting a training regimen that works best for your genes and, therefore, body type… right? If you look like this, your body type is this, and this is, thus, how you should eat and train. Unfortunately, no. Similar to how research has failed to show any statistically significant difference in weight loss between overweight people who ‘eat right for their genotype’ and those who do not, body type training appears just about as useful as a sunroof on a submarine.

Here’s the thing. There’s no denying that somatotyping (the system of classification of body types) works great for describing an individual’s physical appearance. Thin and tall? You’re an ectomorph. Short and fat? Endomorph. And if you’re athletic and muscular? Well, you’re a mesomorph. But go beyond this, and the system falls apart — especially when it comes to predicting how well an individual responds to a certain way of training and eating. To find out why let’s explore what body type training is and how the idea was conceived in the first place. And perhaps more importantly, I’m also going to cover how you should train and eat (in a science-based way) instead if you can’t look to somatotyping for answers.

What is body type training?

Body type training refers to the idea that different body types require different diet plans and training methods. The majority of individuals can be grouped among one of three different body types: mesomorphs, ectomorphs, and endomorphs. While it’s generally recognized that most people are a blend of two body types, it’s still widely believed that we should train according to the more dominant type.

Ectomorphic bodies

If you’ve got narrow shoulders, thin wrists, and are naturally lean, you’d be considered an ectomorph. Ectomorphs tend not to store excess fat, and, as a result, always look long and lean, or at the very worst, skinny-fat. In the fitness world, ectomorphs are typically referred to as ‘hard-gainers.’

Now, because ectomorphs are thought to have difficulty putting on muscle, many (misinformed) fitness articles recommend these individuals to:

  • Do the minimal amount of cardio required for general health
  • Lift heavier weights and complete 3 to 5 sets of approximately 8 to 12 reps for each muscle group
  • Eat a diet that is higher in carbohydrates and calories, with the typical breakdown in daily calorie-distribution being 50 to 60% carbs, 25% from protein, and 25% from fat

Endomorphic bodies

If you’re, for want of a better term, ‘big-boned,’ then chances are, you’ll be categorized as an endomorph. It’s said that endomorphs find it difficult to lose fat even when exercising (i.e. ‘slow metabolisms’). Endomorphs are said to have a smooth, round body, small shoulders, and shorter limbs. Because of their build, it’s recommended for endomorphs to:

  • Incorporate both steady-state cardio and high-intensity interval training 4 to 6 days a week
  • Lift moderately-heavy weights and complete 3 to 5 sets of approximately 8 to 15 reps for each muscle group
  • Eat a diet that’s roughly equally divided between the 3 macronutrients, with the typical calorie-breakdown being 30% carbs, 35% protein, and 35% fat

Mesomorphic bodies

If your shoulders are wider than your hips, and you’re of an athletic build, you’re thought to have won the genetic lottery: you’re a mesomorph. In other words, of the 3 body types, mesomorphs are the best for resistance training and bodybuilding as they are naturally strong and can lose or gain weight easily. Because of this, mesomorphs are advised to:

  • Incorporate 30 to 45 minutes of cardio exercise 3 to 5 times a week
  • Lift moderate-to-heavy weights and complete 3 sets of 8 to 12 reps for each muscle group
  • Eat a diet that’s equally distributed between protein, vegetable (or fruit), and whole-grain (or healthy fats)

These recommendations sound logical at first glance, sure, but they honestly aren’t evidence-based. Why? Well, because somatotyping was never meant to be applied to fitness and nutrition in the first place (amongst other issues, which we’ll examine in a bit).

Who came up with these body types?

Instead, the concept was theorized by Dr. W.H. Sheldon back in the early 1940s; he believed that these body types — ectomorph, endomorph, and mesomorph — directly influenced a person’s personality. And the terms were chosen because he hypothesized the predominant traits of each body type were set in stone, derived from pre-birth preferential development of either the endodermal, mesodermal, or ectodermal embryonic layers. According to Sheldon:

  • The lean and long-limbed ectomorphs were cerebral, anxious, solitary, and secretive
  • The roundish, short-limbed endomorphs were jolly, affectionate, and complacent
  • The broad-shouldered and muscular mesomorphs were risk-taking, courageous, and assertive

If you have a frown on your face, I know, I know. What a load of bull. You’ll be pleased to know that the theory that an individual’s personality is determined by body composition has been wholly abandoned by the psychological community (phew). So, why did the concept of body type training even gain traction in fitness circles in the first place?

Honestly, it might be because many of us want an easy solution when it comes to fitness and weight loss. And the idea that if you have ‘X’ body type, then you should train like ‘Y’ and eat like ‘Z’ provides that.

But the truth is, the concept of body type training is terribly flawed. Let’s explore why below.

#1: Your current body type isn’t indicative of your potential

Just because you know your body type, doesn’t mean that you’ll know — for sure — how your body will respond to training. If you start as a lean and lanky ectomorph, for example, you’re supposed to find it incredibly challenging to put on muscle. But is this claim accurate? If you’ve read this section’s subheading, you’ll know it’s not. And this can be illustrated by a 2018 study, where researchers got a group of men who’d never lifted weights to start on a training program that involved working out 3 times a week for 12 weeks. Muscle thickness was measured at the start of the study, and once again at the end.

Guess what the researchers found? Men who started with less muscle saw the biggest gains in muscle size after 12 weeks of training! In other words, those who began the study with the least amount of muscle were the ones who made the fastest progress. The truth is, you could be a person with a low baseline of muscle mass now, but with the potential for rapid growth. And you could also be a person with a high baseline of muscle mass now, but who won’t see the same level of growth when you start lifting weights. Ultimately, there’s no scientific evidence to show that somatotyping provides any value when it comes to predicting who will be a fast or slow responder when it comes to resistance training.

#2: Body type training doesn’t hold up in the long-term

Regardless, let’s assume that, for some reason, body type training works. Let’s take the example of a woman who looks like a typical endomorph — round and on the plump side. She starts on a resistance training program and cuts down on her calorie-intake. Because of her hard work, she loses 10 kg of fat and gains 5 kg of muscle. She now looks lean, muscular, and athletic. Does that mean she’s a mesomorph now? Or should we still consider her as an endomorph because that’s ‘pre-determined’ by her genes? And, perhaps most importantly, should she carry on training and eating like an endomorph? Unfortunately, there are no answers to these questions. Why? Well, because the practical implications of body type training were limited right from the beginning.

#3: The advice is so generic it’s interchangeable between body types

Do me a favor. Go through the various recommendations — both diet- and training-related ones — for all body types again. Be very honest. Would you have noticed if someone switched up the recommendations between the body types? For example, would you have thought, ‘Hmm, that doesn’t make sense’ if I told you that mesomorphs need to incorporate both steady-state cardio and high-intensity interval training 4 to 6 days a week (as per recommendations for endomorph bodies), instead of 30 to 45 minutes of cardio exercise 3 to 5 times a week? You wouldn’t have. That’s because much of this ‘body type training’ advice you read about is so generic that it could apply to just about anyone — regardless of body type.

#4: Your behaviors are going to influence your progress more than your genes

Just in case you think that my stance is ‘genes don’t matter,’ let me first point out that I fully recognize the role our genetics play. As illustrated by fast- and slow-responders, individual variations between two people who start on the same training program and diet plan will exist because of genetic differences. Some people do indeed find it more challenging to lose fat than others. But the truth is, your genes rarely, by themselves, have the power to dictate your destiny. In other words, despite your genetic predisposition, your behaviors are going to exert a bigger impact on your progress.

But where’s the evidence? Well, have you ever heard of the FTO genotype? If you haven’t, it’s a gene most consistently linked with obesity due to its effects on reduced satiety after a meal and stronger appetite-related responses in brain areas when looking at pictures of food. Given this information, you’d think that individuals with the FTO genotype would face difficulties losing weight, right? Surprisingly, several studies have found that these individuals actually lost weight as expected with lifestyle changes like calorie-restriction and exercise. Not to mention, physical activity — including exercise itself and non-exercise thermogenesis (NEAT) — can minimize or eliminate weight gain among individuals carrying the FTO gene.

So, yes, while your genes might predispose you to a certain trait, it really doesn’t mean that you don’t have the power to change your outward appearance. Despite the genetic hand you were dealt with, there are things you can control that’ll help you achieve your fitness goals.

Train according to your goals instead of your body type

By now, it should be clear that somatotyping has no practical implications when it comes to deciding what your diet and training program should look like. So… What now? If you can’t look to your body type for answers, how should you eat and train moving forward? To be very honest, it’s really not as complicated as you think it is. All you need to do is train and eat according to your fitness goals.

For example, if you’re trying to put on muscle mass, you know you need to eat in a slight calorie surplus (especially for trained lifters), get in adequate protein daily, and make use of progressive overload in the gym. And if you’re looking to lean out, you’ll need to get into a slight calorie deficit (by either eating less or ramping up cardio sessions), get in adequate protein daily, and still challenge your body by lifting relatively heavy in the gym so you keep most of your muscle mass while losing weight. Of course, the specifics of training and nutrition programming is really beyond the scope of this article. But you’ll never go wrong with training and dieting according to your fitness goals.

At least it’s evidence-backed. Also, wouldn’t you agree that’s a lot more straightforward than looking in the mirror day-in and day-out, trying to decide if you’re more endomorphic than mesomorphic? As for the bottom line? Rather than worry over somatotypes, determine your specific goal, give your training and nutrition plan a go, and see how you respond. You’ll never know your true potential until you try. And nope, your genes won’t get in the way. Promise.

Thank you for reading! If you enjoy an evidence-based approach to optimizing your training and diet, a good starting point would be learning how much protein you need and why you need to prioritize strength training.

Fitness & Nutrition | Evidence-Based | Let’s meet in your inbox: https://thrivewithscience.com/subscribe/

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