Like a lot of us, there’s a good chance you learned about body types in a junior high health class. At some point during Ol’ Coach McCracken’s begrudging M/W/F obligation to trade the gym floor for the chalkboard, he probably introduced his young and impressionable charges to a classification system of three somatotypes. And, on the surface, they appeared pretty reasonable.
There were short, pudgy bodies. Tall, skinny bodies. And, somewhere in between, medium-height, “athletic” bodies. All you had to do was look around the classroom to see the evidence with your own eyes.
The next step was inevitable. Pretty soon everyone got to thinking, “What’s my body type?” And that’s where the whole lesson started to break down. For most of us, it’s never been that easy to tell which body-type category we belong to — not that it matters.
What Are the 3 Different Body Types?
The reason why it’s generally difficult for people to identify their body type is that the whole notion of a three-sizes-fit-all classification system has never been backed by solid science. Just in case you forgot that long-ago class — or, more likely, texted or slept through it — a brief review may be in order.
In the 1940s, a University of Houston professor named William Sheldon contrived the concept that all humans fall into one of three body types, or somatotypes:
Ectomorphs are described as long and lean, with little body fat or muscle. Weight gain can be difficult, but weight loss comes relatively easy. Imagine Thandie Newton or Bruce Lee.
According to Sheldon, endomorphs carry plentiful reserves of body fat and muscle, making weight gain easy and weight loss consequently harder. Here we think of Beyoncé or Chris Pratt (circa Parks and Recreation).
Mesomorphs are characterized as athletic, solid, and strong — daywalkers between the other two somatotypes. Let’s go with Mark Wahlberg or Ronda Rousey.
Strangely enough, Sheldon wasn’t interested in cataloguing body types for fitness purposes. He was a psychologist who posited that it was possible to attach personality traits to each body type. He was more interested in how our bodies presumably shape our character than how they actually functioned.
Sheldon posited that ectomorphs were introverted, artistic, and emotionally intense. Endomorphs were jolly, relaxed, and sociable. Mesomorphs were assertive, adventurous, and competitive.
The three-body-types theory gained so much attention so quickly that it soon passed more or less into conventional wisdom. And why not? Sheldon’s system seemed to explain a lot. Think of your favorite SNL “fat guy” comedian (seems there’s always one on the cast). Classic endomorph, right?
Actually, wrong. Like the zodiac, somatotyping works because pretty much everybody can find something of themselves in just about every “personalized” designation.
As it turns out, the three-body-types theory had no basis in science at all. Sheldon drew his conclusions based largely on observation. It’s classic junk science.
Why Does the Body-Type Myth Persist?
Let’s repeat that most important point. The theory that there are three basic body types — or that you can divine a personality type or tailor an exercise regimen around one — is pure nonsense. It’s not supported by scientific evidence. In fact, Sheldon’s entire motivation for his study has been thoroughly renounced.
“Sheldon’s toxic eugenic views and equation of physique with destiny in the years following World War II made him increasingly unpopular,” according to a 2015 article in the Canadian Bulletin of Medical History. “The death knell of his career was dealt by his former female assistant, Barbara Honeyman Heath. Publicly denouncing his methods as fraudulent and his somatotypes inaccurate she went on to build a successful career modifying somatotyping techniques and participating in projects all over the world.”
“Few people fit entirely into one of the classic body types anyway,” says Trevor Thieme, C.S.C.S, Openfit’s senior fitness and nutrition content manager. “Most people are a mishmash of them. For example, you might have the upper body of a mesomorph and the lower body of an ectomorph. But being able to classify your body type doesn’t really matter, because it won’t necessarily inform you about what does: How your body will respond to training.”
You’d think with that kind of emphatic beatdown from the medical and fitness establishments, Sheldon’s idea of three primary body types would have gone the way of the Segway, Zune, New Coke, and Cheetos Lip Balm (yeah, that was a real thing).
But the myth of somatotypes is surprisingly strong, as any quick Google search will tell you. For just one of far too many examples, as recently as 2016 London’s Daily Mail newspaper asserted, “Scientists say we all fit into three groups (and knowing your shape is key to choosing the right workout).”
That simply isn’t true. But it does beg the question: why is this fitness myth harder to get rid of than those last few pounds of belly fat?
“I think that a lot of it has to do with the fact that most people want an easy solution when it comes to fitness and weight loss,” says Thieme. “And the idea that if you have X body type then you should focus on Y exercise type provides that.”
But such thinking is backwards, says Thieme. “You need to start with your goal, because that is going to shape your training program, regardless of your ‘body type.’”
How to Train Regardless of Your “Body Type”
Starting with your goal and working backwards to determine your optimal training plan is actually pretty freeing. It means that if you’re a classic ectomorph, you don’t have to favor distance running over pumping iron, and if you’re an endomorph, there’s no reason why you shouldn’t train for a marathon if that’s on your bucket list. You might even surprise yourself, bulking up quickly even though you’re tall and skinny, or discovering that you have a huge aerobic engine despite the fact that you wear extra-large running jerseys.
The key point here is that you’ll never know what you’re capable of until you try it. Or as a white coat might put it: somatotype doesn’t predict training response.
The role of genetics
To be clear, that doesn’t mean that the training field is level. Regardless of your goal or the route you take to get there, odds are that you’ll encounter people who travel it faster or slower than you, because what’s written in your DNA is still important.
“There are many factors we can manipulate to our advantage depending on goals — training frequency, training intensity, what exercises we prioritize, programming periodization, nutritional factors — but it’s also important to understand some people picked the right parents,” says Tony Gentilcore, CSCS, owner of CORE, his training studio in Brookline, Massachusetts. “Some people just look at a dumbbell and they grow. Some people have to fight tooth and nail and work out a lot in order to see the fruits of their labor.”
The most important factors in choosing a workout
And that’s the case regardless of your ultimate goal. “But at the end of the day, what’s going to ‘work’ is anything that you actually like doing and that you’ll stick to consistently,” says Gentilcore.
So tailor your training to your goals, workout preferences, time constraints, and strengths and weaknesses, advises Thieme. “Your training plan needs to be customized to you as an individual, not based on a body type category that wasn’t even created with exercise in mind.”