Did you make a healthy resolution this year? Whether your goal is to lose weight, cut back on caffeine, start running, or just feel stronger in your favorite classes, your genes might make or break your ability to follow through and succeed. We talked with Dr. Dan Reardon, co-founder of DNA analysis and testing site FitnessGenes, to learn more about how science, physiology, and diet can affect our physique and our ability to meet fitness-focused goals. FitnessGenes is a service that analyzes your DNA (through a home collection kit) to give you a genetically tailored nutrition and fitness plan.

“Resolutions require a level of dedication to new habit formation, but this is exceptionally challenging when the program isn’t right for your body,” Dr. Reardon acknowledges. “As scientists and doctors, we had a unique perspective. We looked at the growing rate of obesity and questioned why people continue to use trial and error as a fitness solution; our combined knowledge of science, physiology, and diet gave us an advantage that we wanted to share with the world.” For his team, de-mystifying how humans interact with food and fitness is always at the heart of what they do. To help us better understand, Dr. Reardon broke down the five genes that most affect health and fitness for humans everywhere.

5 FITNESS GENES YOU SHOULD TO KNOW ABOUT

1. FTO: “Often referred to as ‘the fat gene,’ FTO is associated with risk of weight gain,” Dr. Reardon explains. “Carriers of the ‘risk’ variation of this gene are biologically programmed to eat more through an increased appetite, leading them to eat more often and crave high-calorie foods.” He tells us that while it was actually once an evolutionary advantage in times when food was scarce, it’s become a risk factor, as calorie-laden foods are easily available. “If you do carry this variation, personalized recommendations will help you control your hunger and achieve your body composition goals,” Dr. Reardon promises.

2. ACE: This gene is associated with athletic performance, and can help you understand if you’re better suited for endurance or to be a power athlete. “People who carry one variation of this gene have a higher percentage of slow-twitch muscle fibers, which makes them more tailored to endurance activities like marathon running,” Dr. Reardon explains. “Those with the opposite variation are predominantly fast-twitch, so are great for sprinting.”

3. CYP1A2: Love your morning cup of joe? Dr. Reardon asked us if we’ve ever wondered about how much caffeine we should consume each day and how long we feel the effects. “I ask because the answer to these questions is largely influenced by your CYP1A2 gene variation — it produces the protein that removes caffeine from your bloodstream.” He shares that the three variations of this gene produce different amounts of protein, making people ‘slow’ or ‘fast’ caffeine metabolizers. “Interestingly, the rate at which you metabolize caffeine can also be affected by lifestyle and environmental factors, such as your diet and whether or not you smoke. Knowing how you process caffeine can help you choose the best time for pre-workout supplements; you’ll be able to maximize their effects.”

4. UCP2: You may have cracked a joke or two about your metabolism before, especially if you’ve tried to lose weight. Turns out, having a “fast” metabolism is actually not a good thing. “A ‘fast’ metabolism means that your metabolism is inefficient and doesn’t convert all the food you eat into energy. Instead, a significant percentage of it is being lost as heat,” Dr. Reardon shares. “This can definitely work in your favor if your goal is to lose weight, but it’s a problem for people who want to build muscle or enjoy endurance sports where you need the energy from every calorie.” Dr. Reardon says that the three variations of the UCP2 gene show varying metabolic efficiency, and knowing yours can help you understand exactly how much energy you get from what you eat.

5. LCT: The last gene on Dr. Reardon’s list, LCT, allows our bodies to produce the enzyme lactase, which digests lactose after infancy. “If you’re able to comfortably consume dairy products into adulthood, then you’re actually a genetic mutant!” he says. “This genetic mutation first showed up in ancient European farmers, and has spread through natural selection.” Interestingly, lactose tolerance is still a minority trait — more than 75 percent of the world’s population carries the lactose intolerant variation of LCT.

Did you make a fitness-based resolution this year? Tweet us about your goals and progress @BritandCo!

(Photo via Getty)

Krista Gray
Krista Gray is a web producer and freelance writer who lives in San Francisco. When she's not working with clients through her company GoldSquare, she loves reading, traveling, and learning new things.