How Much About Exercise is in Our Genes?

Many of us, after an exhausting week or month or even a year of working out, have looked in the mirror at our progress and thought, “That’s it?” We seem stuck in first gear, and we may have blamed it on our diet or our exercise regimen, but we can also point to our genes.

And new studies show that genes are a key to how we benefit from exercise.

But before you tear up your gym membership, thinking your DNA is what’s been preventing you from getting rid of that pot belly, so far these studies have only been done in mice. And these mice were bred specifically to be absolute crap when it comes to working out. Yes, they actually genetically engineered animals who can’t workout, taking male and female mice who performed awful on running tests and mating them until the ideal specimen of exercise-hating rodent had been perfected.

And when they looked at the hearts of the poorly-performing mice, they found that their left ventricles did not expand, something that happens to almost all animals when they undertake endurance exercise. This seemed to be a purely genetic defect. And not only did these mice not perform better after they had been put on tiny treadmills (seriously, tiny treadmills),  but they actually lost fitness because their non-enlarging ventricles made them more tired. And all of this was the fault of the faulty mouse genes.

So wait, you’re thinking, since mice and humans are so similar, why can’t I blame my parents and their parents for my love handles? For one, this is all very new so the factors behind everything that helps or hurts us in the gym, including diet and how hard we are actually pushing ourselves and the reality of our expectations. And secondly, you may not have hit the genetic lotto, but we doubt if you trace your lineage back generations, you’ll find that every one of your ancestors was last in gym class. Your climb up may be more grueling, but that doesn’t mean you have an excuse to lie down at the bottom.