"Do you struggle to motivate yourself to go to a gym?" Sharad Paul, MD, asked me over email. Yes, I thought without blinking. "How many times have you signed on to a gym or fitness center and ended up cancelling the membership because you couldn't be bothered?" he continued. More than I'd like to admit on the internet, I said to myself. We were discussing the idea that some people have a predisposition to certain forms of exercise based on their genetic makeup. My genes, I learned, speak to my loathing of a regimented workout schedule. Yes, there are "laziness genes," and I have them. (Thanks, Mom and Dad.)
In his book, The Genetics of Health, Paul discusses in great detail the differences in the way we interact with health and exercise based off our DNA. Below, he describes how to tell which exercises you're most likely to excel at based on your corresponding genes. To find out your personal makeup, test your genes, and then keep reading.
1. Power Genes
Power exercises are those that use your own body weight—including push-ups, sit-ups, lunges, weight-lifting, and working with resistance bands. Any household chore that involves lifting a weight (grocery bags) or your own weight (climbing stairs) also qualifies. As we get older, it is especially important to maintain power exercises, as they help reduce sugar levels, get rid of excess fat, and improve our posture and brain function.
The ACTN3 gene determines if your genes make you a natural at strength and power exercises. It encodes the alpha-actinin-3 protein, which is only expressed in fast-twitch muscle fibers. (They fatigue faster but are used in powerful bursts, like sprinting.)
Here's the breakdown: If you have the CC variant of ACTN3 gene, you are significantly more likely to excel at strength-based activities. If you have the TC variant of the ACTN3 gene, you have a slightly enhanced power and strength potential.
2. Endurance Genes
Endurance exercises cause our heart rates to increase, like brisk walking, running, biking, and swimming—anything you'd refer to as "aerobics" or "cardio."
VO2 max, or maximal aerobic capacity, is a measurement of the maximum amount of oxygen that your body processes during one minute of exercise and is a marker of your physical fitness. It is no surprise that some people are naturally better bike riders, long-distance runners, or swimmers. With the NFIA-AS2 gene, individuals with the CC variant tend to have greater VO2 max, which is advantageous for endurance exercise such as running or biking. The GSTP1 gene, which codes the enzyme glutathione S-transferase P1, causes great improvement in VO2 max when one is undertaking aerobic training. Together, these genes can predict your genetic advantage for excelling in endurance activities, and in the future, it will be used to predict athletic performance even more.
3. Laziness Genes
We now know that individuals who possess the AA or AG variant of the BDNF gene are more likely to experience positive mood changes and exercise for enjoyment. They also perceive their effort and exertion level as lower during exercise compared to individuals who possess the GG variant. In other words, if you have the GG variant, your gym-aversion could be a genetic trait.
However, there is hope—the more you practice endurance training, the more you end up expressing new, helpful motivational genes. Studies found that when mice were trained with regular endurance exercises, they activated new genes and had innately high levels of substances that promote tissue growth and health.