Body Types: Mesomorph, Ectomorph, & Endomorph Explained

If you walk down the street of your nearest downtown on any given day, you will likely notice that bodies come in all shapes and sizes. Diverse body types have been used across all cultures to portray current societal norms for beauty, wealth, health, and status (using sculptures, art, fashion, advertisements, etc.) since well before the 1900s.

This fascination with appearance and shape eventually led to scientific research to classify the 3 body types we know today (endomorph, mesomorph, and ectomorph), to determine the reason that we have that body type, and whether or not it can be altered by our lifestyle and health choices.

Keep reading to learn more about the 3 body types, how to identify them, and how to train according to your body type to reach your fitness goals.

Table of Contents

● What is a Body Type?

● What Are the Three Body Types
● How to Identify Your Body Type
● How to Train Clients Based on Their Body Type

What is a Body Type?

A body type, or a somatotype, refers to the idea that there are three generalized body compositions, or body shapes, that people generally fall into. The concept was theorized by Dr. W.H. Sheldon(1) back in the early 1940s, naming the 3 body types: endomorph, mesomorph, and ectomorph.

At the time, Dr. Sheldon believed that these body types were predetermined, unchangeable, and that they also directly influenced a person’s personality traits. The body type link to personality traits eventually fell out of favor within the science community, but the 3 body types are still used today to develop personalized health and fitness plans for people.

The Body Type Spectrum

Although the notion of a predetermined and unchangeable body type has been debunked since the 1940’s, it is true that many of the physiological markers and observations associated with each somatotype do actually exist in the greater population. However, no one exists purely within one body type; instead, we are all constantly in flux and fall uniquely on a spectrum somewhere between all three. Lifestyle factors, like nutrition and exercise, play a significant role in determining where we fall on that spectrum at any given time.

Want to learn about the nutritional side of our body types? Join NASM Master Instructor Rich Richey as he details how nutrition fits in with our unique body types.

What Are the Three Body Types?

The 3 body types are: endomorph, mesomorph, and ectomorph. While body types are often discussed in relation to women and fashion, a body type is not gender-specific. Both men and women will fall into one of the 3 body type categories. Here’s a breakdown of each body type and some of their most common characteristics:

Endomorph: More round or soft physique, gains and stores fat more easily, loses fat slowly, naturally slow metabolism
Mesomorph: Naturally muscular and athletic with shoulders wider than the hips; efficient metabolism making it easy to gain muscle and lose fat
Ectomorph: Slender with less muscle mass, narrow shoulders and hips with respect to height, naturally fast metabolism making it difficult to gain mass

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Female Body Types

Women come in all shapes and sizes and even have their own list of body type descriptors, used especially in the fashion industry. Some familiar examples of these body types are:

Pear-shaped: Narrow shoulders, wider hips
Apple-shaped: Round throughout the torso, lean legs
Carrot: Broad shoulders, narrow hips
Celery: Rectangular in appearance
Hourglass: Equal size across the bust and hips with a narrow waist

This list doesn’t negate the 3 main body types used for men and women. The female-specific body type descriptors are more often used in the fashion industry to help women select the styles that will best compliment their shape.

Although it is more common now to see most of these body types represented in fashion magazines and the media, that wasn’t always the case. Starting before the 1900s, the fashion industry has served as a visual example of the “most acceptable” body type for culture. Many women have felt pressured by these images to fit into a certain body type in order to be considered beautiful or successful. Thankfully, over time, we’ve begun to realize (and portray in popular media) that beauty and health aren’t found only in one single body type.

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How to Identify Your Body Type

A body type doesn’t define or limit a client based on their appearance, rather it can be used as a powerful tool for fitness professionals to help their clients reach their current goals. When you know the assets and challenges that are associated with each body type, this information becomes an aid as you put together a fitness plan for your client, taking the guess-work out.

When identifying body types for yourself or for a client, consider the characteristics of the 3 body types listed above for endomorphs, mesomorphs, and ectomorphs. Many of these characteristics can be identified visually, like bone structure and the amount of muscle mass or fat the client carries. For some of the other qualities, you can ask your client (or yourself) a few key questions:

Do you find it easy or hard to gain muscle mass when you try?
Do you have any metabolic or chronic conditions? (these may indicate a slow metabolism)
How easy or hard is it for you to gain weight? To lose weight?

These questions along with visual observations can help you to identify which of the 3 body types you or your client fit into the most.

Can I Change My Body Type?

A person’s observable body type represents the current sum of their physical, dietary, and lifestyle choices up to that point in time, combined with a variety of uncontrollable factors, like genetics and surrounding environment (i.e. access to healthy food and a safe place to exercise). The fitness industry, at its core, is all about helping people learn to use the tools they can control (i.e., improved lifestyle, diet, and exercise techniques) to overcome challenges presented by genetics and environmental factors that they otherwise have no agency over. By making intentional and consistent changes to your lifestyle, physical activity, and nutrition, you can change your body type over time.

It’s important to remember that even if your physique isn’t where you want it to be, it’s okay to have a positive self-image of right where you are today. Focus on all of the wonderful things that your body can do right now! Avoid comparing yourself to others, and spend time with supportive people. By maintaining a healthy self-image, you’re more likely to enjoy the process should you decide to take action and change your body composition in some way.

How to Improve Body Composition

Changes in body composition don’t happen overnight, but they certainly are possible! Research continues to prove that physical training and consistent, habitual changes to diet have a strong influence on improving body composition. Metabolic and chronic health conditions that were once considered major roadblocks to weight loss success can now be managed and even improved by modern medicine in conjunction with healthy lifestyle changes.

So why does it seem so hard to see a shift in body composition?

Let’s face it: change is hard. When you’ve lived your life one way for as long as you can remember, it takes time and effort to begin to make changes that stick. This is where hiring a Certified Personal Trainer, Certified Wellness Coach, or Certified Nutrition Coach can make all of the difference. These professionals can help you make a personalized plan that fits your needs and your goals while offering the accountability that you need to keep you moving forward over time.

Once you’ve made changes to your physical activity patterns, nutrition, and other lifestyle factors, your body composition will eventually reflect your new way of living. Over time, these habits that once took significant effort to maintain become more deeply rooted into your everyday life and simply become your “new normal”. It’s at this point that you might notice that some of your body type characteristics have shifted to reflect more mesomorphic (athletic, fit) traits.

How to Train Clients Based on Their Body Type

Once you identify which body type you or your client most aligns with, consider the benefits and challenges that are associated with it. This can help you tailor the exercise programming and dietary coaching to overcome those hurdles. Consider the goals of the client. Do they want to get in shape? Lose weight? Gain muscle mass? Keep the client’s goal in mind and evaluate whether you are using the right methods for the body type they currently display.

Most clients come in with the goal of developing more of a mesomorph body type, but there certainly are exceptions to this rule. For example, a distance runner may want to maintain an ectomorph body type and a linebacker might need their endomorph body type to succeed in their sport. Use the following tips to help your client leverage their strengths and overcome any barriers when it comes to achieving their health and fitness goals.

Training for Endomorph Body Types

For most endomorphs, the goal is to lose body fat and to build a more fit physique. An endomorph may already be strong and athletic, but for those wanting to shift to a more mesomorphic physique, metabolic training and healthy nutrition will be key.

For strength training, work through OPT Phase 1 and Phase 2, but keep the majority of training sessions focused on metabolic conditioning. You can do this by minimizing rest time, using circuits for resistance training sessions, and including plyometrics (as tolerated) in your sessions.

Maximize calorie burn and improve metabolic efficiency by primarily using high-intensity, metabolic training techniques. Consistent anaerobic and aerobic training will help endomorphic bodies increase metabolic efficiency and boost the daily calorie burn of the individual. These clients will also benefit from increasing their daily non-exercise activity thermogenesis (NEAT) factor as much as possible, moving more during times of the day when they’re not in the gym.

Consume a high-protein diet with balanced carbs and fats while maintaining a slightly negative energy balance (aka calorie deficit). This strategy helps the client to maximize fat loss while still supporting, and even building, existing lean muscle mass. Diets containing daily protein of as much as 2.2 grams per kilogram of body weight have been shown safe and effective for supporting existing muscle tissue during times of calorie restriction and weight loss. The remaining calories can come from whatever blend of carbs and fats the individual best tolerates. Use NASM’s Calorie Calculator to help you calculate these as you piece together a plan.

Training for Mesomorph Body Types

A mesomorph may not be interested in changing their body type, but rather in pursuing a specific fitness goal or perhaps even gaining more muscle mass. Their fitness goals will help you decide which of the following adjustments can be made to their fitness and nutrition programming to help them succeed.

Utilize OPT Phases and cardio strategies directly aligned to client goals. Mesomorphs already have a relatively efficient metabolism. They carry functional – if not athletic – muscle mass, and are essentially ready to take on whatever fitness goal they please. Just like any new client, build a solid foundation with OPT Phase 1 training, and then pursue other phases as they align with the client’s goals.

Eat specifically for fitness goals and activity. Increase or decrease daily calories to control body composition with positive, neutral, or negative energy balances as needed. Mesomorphs should consume anywhere between 1.2 and 2.2 grams per kilogram body weight of protein, depending on the intensity of the exercise program, with remaining calories coming from a blend of healthy carbs and fats. Daily caloric intake can be modified based upon body composition goals and daily caloric expenditure.

Adjust protein intake to match muscle gain goals. Increase protein intakes to up to 2.2 grams per kilogram of body weight for muscle gain goals. If muscle maintenance is all that’s desired, keep protein intake around the 0.8 grams per kilogram of body weight as recommended by the FDA recommended dietary allowance (RDA).

Training for Ectomorph Body Types

Ectomorphs typically have a hard time putting mass on and often wish to change that in order to have a more fit or muscular appearance. Because they already have a high metabolism, the focus of their program will be strength training and a nutrition plan that supports muscle gain.

Maximize muscle gain using lower-intensity hypertrophy (Phase 3) and maximal strength resistance training (Phase 4) with longer rest periods. After working through the initial level of the OPT model, Phases 3 and 4 will be of most benefit to average clients in this population. NASM’s Hypertrophy and maximal resistance training are primarily anaerobic in nature, and when combined with longer rest periods, these styles of training won’t stimulate elevated calorie burn like more intense, fast-paced exercise programs will.

Minimize cardio to avoid burning excess calories. The primary focus of the training program should be muscle-building activities, as ectomorphs can already burn calories and lose weight with ease. Doing too much cardio can work against any muscle-building goals for this client.

Consume a high-protein diet with balanced carbs and fats, consuming a calorie surplus to facilitate muscle and weight gain. Ectomorphs need higher levels of protein, 1.2 to 1.6 grams of protein per kilogram of body weight, to gain muscle and mass, with some individuals requiring up to 2.2 grams per kilogram of body weight.

Final Thoughts…

There’s no such thing as the perfect body, but there’s also nothing wrong with wanting to be the healthiest version of you. Your body type is not a life sentence. While you can’t change your genetics or environmental factors, you do have control over your lifestyle choices and your nutrition and exercise. Choosing nutrition and exercise that pair well with your current body type (and sticking with it over time) can lead to serious transformation and help you feel your best.