The Secret Ingredient to Sports Success: An Interview With David Epstein On The Sports Gene

The Sports Gene
Maybe its not all about practice.  Since the youth sports world fell in love with the romantic notion that 10,000 hours of structured practice is the magic ingredient to world-class mastery in just about any field, especially sports, we've forgotten or ignored that our genetic endowment may still have something to do with the outcome.  Just watch this video of a young Lionel Messi, who was probably still working towards his 10,000 hour total at the time.  He clearly has something else, something that was already there at age 5 and something that the other kids didn't have.

David Epstein, senior writer at Sports Illustrated, has been on a search for that extra something.  In his new book, The Sports Gene, Epstein launched himself directly into the nature vs. nurture, genes vs. practice and natural vs. self-made debates about athletic greatness.

I recently had a chance to chat with David about his book and found out that there is a complex, misunderstood mixture of variables in the magic formula:

David, congratulations on your new book!  One of my all-time favorite SI articles of yours is the 2010 piece “Sports Genes”.  At the time, you opened many eyes on the influence of genetics on athletic performance.  Is it safe to say that the science and our understanding of it has come a long way in the last three years?

David Epstein
David Epstein: I appreciate that! I think it safe to say that the science has come a very long way in the last three years. At the same time, the studies of genes related to sports performance is still hampered by certain problems. A decade ago, scientists hoped that genetics might be simple; that single traits, like, say, height, might be attributable to a single gene or a small number of genes. But now it’s clear that most traits—and certainly those as complex as athleticism—can involve large numbers of genes, each with a small effect. That can make things particularly tricky for studying elite athletes, because there aren’t very many elite athletes in the world, so studies are often too small to detect the effects of relevant genes. 

Still, using certain innovative methods, like those described in chapter five of my book, scientists are pinpointing some of the genetic influences on an individual’s ability to adapt to a training regimen. And that now looks to be a key component of “talent,” not simply some skill that manifests prior to training, but the very biological setup that makes one athlete better at adapting to a particular training plan. In recent years, both with respect to endurance and strength training, the science has increasingly shown that genes mediate the ability to “respond” to training, and it appears that work will continue to be bolstered. People often say “I’m not very talented in this or that area,” but the genetic work is increasingly showing that we can’t necessarily know if we have talent before we try training.

In the book, you tell the story of Dan McLaughlin, an amateur golfer, who has put his life on hold while he accumulates the infamous 10,000 hours of deliberate practice towards his goal of playing on the PGA Tour.  You document how genetics can offer exclusive physical advantages for sprinters, swimmers or even baseball batters.  However, in sports like golf, dominated more by mental skill than brute physical abilities, does genetics still play a role or is it all about practice?

DE: That’s a great question. For starters, there is less scientific evidence regarding genes that influence skill in very technical sports, like golf, but that is partly because those skills are difficult to study. We have enough trouble finding genes for simple traits, like height, and physiologists don’t even understand everything that makes a great golfer, much less the genes that undergird the particular physiological traits. As Sir Roger Bannister once said: “The human body is centuries in advance of the physiologist, and can perform an integration of heart, lungs, and muscles which is too complex for the scientist to analyze.” No where is this complexity more difficult for scientists to link to specific traits than in sports based on specialized skills. So one reason there’s more known about genes—or innate physiological traits—that influence the more raw athletic skills is simply because scientists more often choose to study athletes engaged in more “raw” sports. The idea is it will be easier to find the biological influences. 

That said, there are mounds of studies that show that when individuals practice motor skills, differences in the rate of progress become apparent in all but extremely simple skills. In some studies, the more complex the skill, the greater the differences between individuals will become as they practice. In other words, there are differences in “trainability.” Which genes are at play here is largely a mystery, but that doesn’t mean they don’t exist. Remember, we don’t know many of the genes that influence height, and yet from studies of families and large populations, we know quite well that differences in the heights of adults in any given population are generally at least 80% inherited. 

To use an example relevant to some of the writing in my book, left-handed people are highly overrepresented among chess masters. We don’t know what the “left handed genes” are, but we know there is a genetic component. Men are about twice as likely to be left handed as women, for example. So it would seem as if certain genes for left-handedness, which of course means brains that influence motor control in the brain, interact with the learning of a skill like chess. As a related aside, Belgian scientist Debbie Van Beisen has shown that competitive table tennis players with mental handicaps fail to learn the anticipatory cues required to return shots as quickly as similarly experienced table tennis players who do not have mental handicaps.

Additionally (and I actually had to trim much of this from the book) there is some interesting work implicating specific genes in motor skill learning. Here’s a snippet I had to cut from the book, as my first draft was WAY over printable length:

“The level of BDNF is elevated in the brain’s motor cortex when people learn a motor skill, and BDNF is one of the neural signals that coordinates the reorganization of the brain when skills are learned. And a 2006 study found that, when people practiced motor skills with their right hand—like putting small pegs in holes as quickly as possible—the area of the activated brain representing the right hand, the neural “motor map,” increased in size with practice only in those people who did not have a met version of the BDNF gene. All of the subjects started with similar sized motor maps, but only the non-met carriers experienced a change with practice.

And in 2010 a group of scientists led by neurologist Steven C. Cramer set out explicitly to test whether the BDNF gene impacts the kind of memory involved in motor skill learning, and their findings suggest that it does. In that study, people drove a car along a digital track 15 separate times in one day. All of the drivers improved as they learned the course, but the met carriers did not improve as much. And when all the drivers were asked back four days hence and made to drive the course once more, the met carriers made more mistakes. When scientists used fMRI to look at the drivers’ brains as they practiced simple motor skills, they found different patterns of activation in the people who had a met version of the BDNF gene.”

Recently, Atlas Sports Genetics has caused a stir in youth sports by offering parents a test for their kids to look for a certain variation of the ACTN3 gene, otherwise known as the “speed gene.”  You mention that this test is only useful to know if your youngster is the next Usain Bolt or Carmelita Jeter, something parents probably already know.  What’s next on the horizon for genetic testing for young athletes?  Are there genes or combinations of genes for traits like reaction time, balance or coordination?

DE: First, just to clarify, the ACTN3 gene is only really useful for telling you that your youngster will not be the next Bolt—if they don’t have the so-called “right” version for sprinting. But it doesn’t even do a very specific job of that, since most people have the “right” version. And, let’s face it, you can take your kid to the playground and have him race the other kids and you’ll get a better idea of his chances of becoming the next Bolt than you would with a genetic test. 

As far as the next frontier of genetic testing for young athletes, I think it will undoubtedly be “injury genes,” before performance genes, and we’re already actually starting to see a bit of that. I spent some time with Brandon Colby, an L.A.-based physician who treats retired NFL players, and—at the behest of parents—he already tests some teenagers for their version of the ApoE gene. As I write in the book, one version of this gene makes an individual more susceptible to brain damage from concussions or the kind of hits to the head to occur on every football play. There are other gene variants that put some athletes at risk of dropping dead on the field, and others that appear to increase the risk of an injury like a ruptured Achilles tendon or torn ACL. 

As I discuss in the book, some of these genes are actually now being used for practical purposes, and I think that we’ll see that increase. As for reaction time, I don’t think we’ll see much there, given that, as I explain in the first chapter, the simple reaction times—the time it takes one to hit a button in response to a light—of elite athletes are no different than those of teachers, lawyers, or college kids. The skills that allow hitters to intercept 100 mph fastballs are learned perceptual skills, not innate reaction abilities. And even if simple reaction time was important, it would be way easier to measure directly—by giving someone a reaction time test—than indirectly by looking at genes.

Here at Sports Are 80 Percent Mental, we talk a lot about the brain’s role in playing sports.  From vision to perception to decision making to emotions, the brain plays a critical role in sports success.  What have we learned about neurogenetics that can influence an athlete’s performance from a cognitive perspective?

DE: One of the most surprising things I learned in my reporting was that scientists know quite well that not only does the dopamine system in the brain—which is involved in the sense of pleasure and reward—respond to physical activity, but it can also drive physical activity. 

One of the scientists I quote in the book suggests that this may be why very active children who take Ritalin, which alters dopamine levels, suddenly have less drive to move around. That’s precisely what he sees when he gives Ritalin to the rodents he breeds for high voluntary running, anyway. And it appears that different versions of genes involved in the dopamine system influence the drive to be active. (Interestingly, native populations that are nomadic and that migrate long distances tend to have a higher prevalence of a particular dopamine receptor gene; the same one that predisposes people to ADHD. I discuss in the book the possible link.) 

One of my takeaways from the research I did for the book was that some traits we think are innate, like the bullet-fast reactions of a Major League hitter, are not, and others that we often portray as entirely voluntary—like the compulsive drive to train—can have important genetic components. Additionally, the section of the book that deals with pain in sports, and discusses the genetics of pain, gets into the fact that the circuitry of pain is shared with circuitry of emotion. (Morphine, after all, doesn’t so much dull pain as make one less upset about it.) And the first genes that are emerging that might allow athletes to deal calmly with pain on the field—like, perhaps, the COMT “warrior/worrier” gene—are genes involved in the metabolism of neurotransmitters in the brain. And, of course, as I mentioned in my longwinded answer to the second question, there are genes that appear to influence motor learning.

David, you were a competitive runner in your college days at Columbia and I understand you still run quite a bit.  Has the research for this book given you any insight or tips that you or other weekend athletes can use?

DE: Indeed I was. I was an 800-meter runner. I still love running, but I’d call what I do now “jogging”! But working on this book gave me certain broad insights that I apply to my own training. In 2007, the prestigious peer-reviewed journal Science listed “human genetic variation” as the breakthrough of the year; the revelation of how truly different we are from one another. And, as J.M. Tanner, the eminent growth expert (and world class hurdler) once put it: “Everyone has a different genotype. Therefore, for optimal development…everyone should have a different environment.” No two people respond to a Tylenol the same way because of their distinct biology, and no two people respond to the medicine of exercise the same way either. 

When I was in college, I had better endurance—at all distances—on a training plan of 35 miles per week that included carefully selected intervals, than I had previously on 85 miles per week of cookie-cutter distance training. If you aren’t taking a scientific approach to your training—and this doesn’t mean cutting edge science, but just paying attention to what you best respond to—then you aren’t getting everything out of yourself. To use track, because it’s just an easy example, in every training group from high school to the pros, you have groups of runners doing identical workouts, and yet never crossing the line at the same time in a race. 

Genetic science is showing us that the most important kind of “talent” isn’t some physical trait that preexists training, but rather that ability to physically adapt to training. And studies I describe in the book make it quite clear that particular genes mediate an individual’s ability to benefit from training such that two people can have drastically different results from the same training plan. 

So if you feel like, for some reason, you aren’t getting results on par with your training partner, you might be right. And the problem might be you, in the very deepest sense. So don’t be afraid to try something different. Several of the athletes I write about in the book weren’t afraid to jump into entirely new activities or training plans, and some came out world champions.

Thank you, David and good luck with the book!