athletes, genetics

What's Your (Genetic) Workout Profile?

Experts weigh in on whether or not our DNA holds the key to our ideal training regimen.

When a simple blood test can reveal gene variations that increase your risk of disease, it’s easy to wonder if certain DNA can forecast fitness, dictating whether you'd be most proficient at (and therefore benefit from) swimming, running, strength training or otherwise. 

The short answer: It might. For example, scientists do see variabilities in muscle fiber types from athlete to athlete. Slow-twitch fibers, which help fuel long-haul exercise, are abundant in elite endurance athletes; sprinters and strength stars have more fast-twitch muscles, which help facilitate quick and powerful movements.

To this extent, the genetic influence on basic aspects of human physiology can, at least somewhat, predispose someone to a certain kind of exercise, says Stephen Roth, Ph.D., director of the Functional Genomics Laboratory at the University of Maryland.

But this is where the issue gets murky.

In genetics, specific genes have garnered media attention throughout the years. Two big ones: A gene called ACE that’s been tentatively linked to endurance; and one called ACTN3, which is associated with sprint performance.

“People in power sports tend to have one or two copies of good variants of ACTN3,” says Michael Joyner. M.D., an exercise physiologist at the Mayo Clinic in Rochester, Minnesota. “You find almost no one in elite power sports without copies.”

Unfortunately, the issue is far more complicated than identifying a speed or endurance gene. While heritability can contribute to psychological and physical performance, researchers don't fully understand which genes contribute to what. “It’s more likely than not that it’s going to be tens or hundreds of genes that contribute—it’s remarkably complex,” says Roth. 

Moreover: “There’s not a simple way to test for fiber type percentages, and there’s not a simple blood test that would give you a sense of your endurance capacity,” says Roth. After all, you could complete a grueling VO2 max test to find out the max amount of oxygen your lungs can use, but even if you have a high baseline, that’s not necessarily predictive of your adaptation to training, he says.

So how can you prime yourself for peak performance? Start with these expert-backed steps.

Become a Generalist: “Instead of testing for genes, the better approach is trial and error within different performance domains—giving yourself a few months to train in an area and see how you progress,” says Roth. “That’s far more likely to show success than any test we have in 2016.”

Consider Family History: “We have a better chance of predicting performance by looking at family history than by looking at certain genes,” says Roth. If your brother was a champion cross-country star, but you never picked up running, commit to a trial three-month endurance program, suggests Roth.

Field Test Yourself: The NFL Scouting Combine is onto something: vertical jumps, bench presses, and cone drills are good predictors of performance because they break down what athletes will actually be doing in competition, says Joyner.

After all, you can have fast-twitch muscle fibers but be slow. Your nervous system and other external factors are at play in performance. “All of those things are summed in a field test. The best test of whether someone can run fast is go have them run a 40-yard dash.”

Consider Your Body Type: Joyner notes that some athletic associations—like British Rowing—have successfully talent scouted tall people in gyms (the long levers in rowing favor those gifted with height), testing them for strength and aerobic capacity. “They have found Olympic medalists this way,” he says. Physical prowess isn’t everything, but if you’ve ever had someone tell you that you may be suited for a particular sport, consider it.