Genetics and Exercise

The NYTimes’s Well blog recently highlighted a study that found genetic evidence for an individual’s ability to become physically fit through exercise (here). Researchers are hoping this may answer the question of why some improve their fitness through exercise while others don’t.

The researchers discovered that one gene marker (called SNP for single nucleotide polymorphism) in particular (on ACSL1) may be of interest. What caught my eye about this?

This gene already has been shown to play a role in how the body metabolizes fats, which might partly explain why it also affects exercise response.

And that right there, folks, is why Gary Taubes’s fat-drives-behavior theory is on the mark. This theory also answers their next question:

How, for one, can any of us tell if we harbor the ideal SNPs for a robust aerobic response to endurance exercise? And if it turns out that we don’t carry those advantageous snippets of genes, can we take to the couch, since our fitness levels won’t budge much even if we dutifully pedal or run?

The first question is simple to answer. We will know we harbor these ideal genetic markers because we will be driven to run great distances or cycle a century ride. If you hid during PE class, I’m guessing you don’t have that SNP. If you’d rather clean toilets with a toothbrush than sign up for a marathon, chances are, you don’t have that SNP. You will know. You will not wander through your entire life lamenting aloud that you have no idea whether your single nucleotide polymorphism on ACSL1 is ideal or not. Most of us are probably somewhere in the middle and enjoy physical activity of some sort but leave the triathlons to others, which probably involves a complex mix of “ideal” SNPs and less “ideal” SNPs.

The second question is more complicated.

It supposes that endurance exercise is the only worthy exercise. That if you’re not out pounding miles of pavement every day, you’re wasting your time. “Well, since I’m not engineered to swim the Atlantic, why bother swimming laps at all?!” Obviously, this rationale is ridiculous. As any follower of Mark Sisson and his Primal Blueprint knows, exercise comes in all sorts of different exertions, like long, slow, and sustained movement, lifting heavy objects, and occasional sprinting. Especially once you have your food life in order, the amount of exercise you need to maintain your physique is amazingly and blessedly less than before with carbs on your plate.

The question also supposes that there aren’t other benefits to exercise, a fact they eventually come clean about later in the post. Stress relief, lower blood pressure, adding strength, maintaining muscle mass and bone density, yadda yadda yadda.

I look at this conclusion in the reverse. Rather than see an excuse not to exercise, I see it as a hall pass to explore other activities of interest. Now that I’ve shed 10 pounds eating Primal, I no longer worry about the number on the scale. Now I want to add more muscle mass, especially since I’ve lost a lot of it since having my daughter. I don’t have to run miles and miles anymore trying to outrun my fat ass, so now I can focus on building strength. Even yoga classes feel more like positive exercise because we do several sets of squats, lunges, and arm balances in one class. A hike through the woods feels complete now, instead of a warm-up for a 6-mile run later. Walking the dog, gardening, playing with your kids, mowing the lawn. All matter again, but not if you have carbs on board.


If you really want a dose of comedy in your day, be sure to read the comments following the article. Wow. I am amazed at the knee-jerk and uneducated responses. Now, I’m no genetics expert. Far from it. I’m constantly asking my husband to explain simple things to me about it. But when I see someone denying that it’s possible that genetics could have anything to do with this? Hmm.

Why do people get upset about genetic explanations? Because you cannot take away from them their belief that they are a unique and sovereign individual who is subject to no forces but the ones they choose for themselves. Even if they are a couch potato, they need to believe that they too could be Michael Phelps if only they applied themselves. Or only had the opportunities. Or only had the right upbringing. These are the same people who will accept that breast cancer can be genetically determined, but suggest that their behavior is? Look out.

THIS is why endurance exercise is so fetishized in our culture: We need to believe we could do it too.

Even from my limited understanding, it occurs to me that EVERYTHING about our human experience is genetically based. If not, then where does our human experience come from? This is not to say that it isn’t possible to make changes. In fact, the more I learn about genetics, the more I realize that each of our genetic maps is not a static blueprint, but a constantly evolving and adapting one. Our experiences count.

So why waste time believing something about ourselves that isn’t true? Get out there and find your thing. What are you well-suited to do?





No comments yet... Be the first to leave a reply!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: