How much of an impact does genetics have on your fitness?

I’m a little obsessed with my ancestry, a hobby that can be very time consuming because each of my parents had over 80 first cousins.

Let me say that again.

That's my grandfather in the front - looking a little like Jon Hamm. He was 5'7. My great-grandfather Joseph was 5'5. 

That's my grandfather in the front - looking a little like Jon Hamm. He was 5'7. My great-grandfather Joseph was 5'5. 

Each of my parents had over 80 FIRST cousins. It's impossible to drive through my hometown without laying eyes on a family member. In fact, I’m pretty sure that most of my readers for this blog are family.

Hi cousins!

Genetics comes up often in a typical day working with clients. Somewhere along the way, we talk about having an apple shape, pear shape, inheriting our mother’s legs or being big boned like our Italian ancestors. 

I personally wonder whether or not my incredibly short legs are at all a factor of the coal mining history my dad’s side of the family shares. Dad and his brothers are all 5’7.

Thanks for those 26 inch inseams Dad! Even petite pants are too long for my little legs. Cheers!

But do your genetics actually limit how fit you can be? Not all of us are built to be basketball players, sprinters, or swimmers. Some have better hand eye coordination than others, which is why I accidentally hit my partner in the face with a softball playing catch when we first met.

I'm still apologize 10 years later.

In regards to fitness though, people often can feel limited by genetics. You might not have the genetic makeup for elite human performance, but you can still improve your overall health, lose fat, and/or gain muscle. But your improvements to body composition and performance might look a little bit different based on your body type. 

Three different body types. 

Normally I don't like putting baby in the corner or Jimmy in a box, but most of us have a body type that fits into one of three categories: endomorph, mesomorph, and and endomorph. These categories were created by American psychologist William Herbert Sheldon back in the 1940's, and the general descriptions, as pulled from Wikipedia (yes, I did that), are as follows:

  • Ectomorph: (thin) characterized by long and thin muscles/limbs and low fat storage; usually referred to as slim. Ectomorphs are not predisposed to store fat nor build muscle.
  • Mesomorph: (muscular) characterized by medium bones, solid torso, low fat levels, wide shoulders with a narrow waist; usually referred to as muscular. Mesomorphs are predisposed to build muscle but not store fat.
  • Endomorph: (curvy) characterized by increased fat storage, a wide waist and a large bone structure, usually referred to as fat, or chunky. Endomorphs are predisposed to storing fat.

So what does this all mean?

Well, first of all, it means you should probably stop hating on Janet from HR because she eats two helpings of birthday cake at each party and never seems to gain any weight. Janet is an ectomorph and she has low fat storage. But you can take comfort in the fact that you could potentially deadlift Janet and throw her across the room if you wanted to do that. But you don't want to do that. Because assault is illegal.

This is also a good reminder to stop comparing yourself with other people. Stop it.

It means that achieving results and fitness won't look exactly the same as Janet or Sally from accounting. If your parents are obese, you run a higher risk of obesity for yourself. Studies on twins show high BMI correlations in adulthood - even in those who have been raised apart from one another, says Brad Schoenfeld, MS, CSCS, author of Sculpting Her Body Perfect. "This indicates a genetic predisposition to obesity and ultimately makes it more difficult for some people to lose weight compared to others."  

Regular exercise A 2008 study published in the Archives of Internal Medicine showed that among Amish people with the FTO gene, a gene associated with obesity and a high BMI, physical activity prevented the weight gain typically seen in people with the gene.

But it also doesn't mean that you can't get fit.

Let me say that again. Your body type does not limit your ability to get fit.  

What it does mean, however, is that while your friend may have found that running was her best bet to stay lean or get lean, because she is an ectomorph and stores fat differently, doesn't mean that running for you, as a mesomorph, is going to be as effective. 

This quote, from Gary Toubes book "Why We Get Fat" is a good analogy.

A greyhound will be more physically active than a basset hound, not because of any conscious desire to exercise, but because its body partitions fuel to its lean tissue, not to its fat.

In a nutshell, my dog is sooooo not wired to run off a bunch of calories. He's just not built like that. He is built for short bursts of energy and long hikes. Greyhounds are like marathon runners. Basset hounds are like...basset hounds. And power lifters. But with more skin and longer ears. 

What does this all mean?

Well, mostly it's a friendly reminder that fitness looks different for everyone. And while we might be genetically predisposed to marathon running or power lifting, we can still get results. Those results might just look a little different.