By: Barbell Logic Team
Gene Testing for Athletic Performance
Watch any group of youth athletes, and it’s clear that when it comes to the strength, speed, power, and the overall athleticism needed to excel, not all kids show up with the same innate abilities. Most kids will participate at about the same level, a few will be off chasing butterflies, but then a few others will stand out as faster, stronger, or in better control over their movements. These few outliers seem physically “gifted,” possibly having won the genetic lottery for good sports genes.
A lot has been made about the role that genetics plays in sports performance. Athletes that succeed at the highest levels are not only more skilled at their sports, but they are also physically capable in ways that most of us simply aren’t. At that level, there’s synergy between the athlete’s physical potential, trained competence, and the specific sport, confluence of factors, some far outside of the athlete’s control, contributing to their success. But it starts with the right genes.
Even though what you’re born with is only one factor that contributes to long-term and elite level success, people treat genetics like destiny in sports. The right genes are a threshold to athletic greatness that most of us cannot cross. There is a kind of grim determinism in that thought.
Now, researchers can test for different genes, and some companies even sell at-home gene testing. These tests are targeted toward parents, typically for children under age 9 when kids “don’t have the physical maturity and motor skills to do well. . . . That’s where the genetic test can come in [handy] for looking for early indicators of talent in performance areas.” (Jordan Lite, “Can Genes Predict Athletic Performance?” Scientific American (2008).) This sounds useful, perhaps, if you want to find the right fit for your child in sports. But how genetics relate to athletics at anything but the highest level is more complicated than genetic predestination.
It’s true that given the right environmental conditions, a person’s performance is capped by their genetic endowment. You cannot express physical capabilities beyond you genetic limits.
What genes make the difference? There has been a lot of hype about the gene ACTN3, which encodes the protein alpha-actinin-3. Studies relating a certain polymorphism of the ACTN3 gene have led to this often being called “The Speed Gene.” This started with researchers discovering a dearth of the gene that leads to an alpha-actinin-3 deficiency in Olympic level sprinters (the XX genotype). The first of these studies discovered a widely varied prevalence of the XX genotype with different ethnicities, but a rare to non-existent prevalence in high-level sprinters. Whereas 18% of the Australian population had the XX genotype, “5 out of 107 sprinters were XX, and zero of the 32 sprinters who had gone to the Olympics were XX.” (David Epstine, “The Sports Gene” (2013).
Since these initial findings, ACTN3 has been tied to athletic development and performance in various ways, including adaptation to exercise and recovery, strength, and protection from eccentric training-induced muscle damage, and sports injury. (Pickering Kiely, “ACTN3: More than Just a Gene for Speed” Front Physiol., 8: 1080 (2017).) Beyond that, researchers continue to identify and study other genes that have some association with performance, but the more they find, the more complex the task of identifying markers for performance becomes. “There are 200 genes we are cataloging as having some positive association with fitness-related performance… and there are 20,000 genes in the genome, so we’re scratching the surface in relation to those studied.” (Jordan Lite, “Can Genes Predict Athletic Performance?” Scientific American (2008)). Sports performance is too complex for us to understand the mechanisms by which these genes seem to affect sports performance. At best, researches are limited to observations at certain levels of performance and loose extrapolations to the role that any given person’s genetic makeup plays in his or her ultimate success.
The idea of genetic testing being predictive is a logical fallacy based on the actual research being done. Suppose that all Olympic sprinters carry a certain gene type. That any particular child has that same gene type in no way predicts that the child will be an Olympian. This is similar to the thinking that just because “All fools are poets” it must then follow that “all poets are fools.” As Poe pointed out in The Purloined Letter this is a fallacy of logic non distributio medii or the undistributed middle.
The role of genetics in sports is a fascinating area of study. It gives insights into human performance and may help us learn more about training and sports development in the future. But as far a predictive power for sports, it is limited. Most people never get close to their genetic potential. Sports and training are far more important than winning at the highest levels. Gene testing might only tell us that out of the two hundred and sixty-five million kids playing soccer only a fraction of a percent will ever become a professional (0.0004% according to a large FIFA study in 2006). But we already knew that.
Some argue that genetic testing as part of a determinative for sports performance is unethical. (See, Camporesi, McNamee, “Ethics, genetic testing, and athletic talent: children’s best interests, and the right to an open (athletic) future,” Physiol Genomics 48: 191–195 (2016)). As one author writes, “It’s just hype as far as I can see . . . If you want to see if someone is going to be a good sprinter, watch them. An educated observer can tell you more than a genetic test.” (Collier, “Genetic tests for athletic ability: Science or snake oil?” CMAJ. Jan 10; 184(1): E43–E44 (2012) (quoting McNamee).) These critics argue that sports, for children especially, have much more to do with their own physical and social development than with the ability to win at the highest levels. Changing that goal may be harmful to their development, supplanting the more basic physical development and social interaction either by pushing them toward their genetic potential for greatness or reigning in a child’s desire for competitive athletics out of the belief that they are not built for one kind of sport or another.
What do you think? Would you like to know what types of activities you are genetically predisposed for? Would that knowledge change how you train or what sports or hobbies you decide to take up?