In some cases, as with the ability of baseball hitters to react to a pitch, a skill that seems based on superhuman reflexes is largely the result of a learned mental database. (Once the database is in place, however, an athlete who possesses outstanding visual hardware can put it to superior use.) In others, as with the ability to respond rapidly to endurance exercise, genes mediate the very improvements that come from hard training. In all likelihood, we overascribe our skills and traits to either innate talent or training, depending on what fits our personal narratives.
Steve Jobs famously said that he had long thought his personality was entirely the result of his life experiences until, as an adult, he met for the first time novelist Mona Simpson, the sister he did not know he had. Jobs marveled at how similar he was to Simpson despite having grown up with a different family. “I used to be way over on the nurture side, but I’ve swung way over to the nature side,” Jobs told the New York Times in 1997. “And it’s because of Mona and having kids. My daughter is fourteen months old, and it’s already pretty clear what her personality is.”
As the study of genes matures, we will increasingly find genetic inputs—some large and many trivial—behind the sports stories we tell. But we are unlikely ever to receive complete answers from genetics alone, and not merely because environment and training are always critical factors. Recall that even for height, an easily measurable trait, scientists needed several thousand subjects and hundreds of thousands of spots of DNA code to account for even half of the variance in height between adults. It is increasingly clear that many traits are influenced by the interplay of large numbers of DNA variations. Thus, studies will require hundreds or even thousands of subjects to get at the genetic root of such traits. But there aren’t thousands of elite 100-meter runners in the world. Additionally, the gene variants that make one sprinter fast may be completely distinct from those that make her competitor in the next lane fast. Remember, with HCM, the disease that leads to sudden death in athletes, most of the distinct, known gene variants that cause the disease are “private” mutations. That is, they have thus far been located only in a single family. The same physical outcome can sometimes be reached via many different genetic pathways.
Nonetheless, as I am writing this, headlines are erupting with the news that Japanese scientists have created fertile eggs from mouse stem cells. On the radio, a scientist just speculated that the breakthrough will ultimately lead to the ability to engineer offspring for specific traits, including athleticism. We can build the perfect athlete, the scientist implied. “It will give parents a great ability to choose the genetic traits of their children,” Stanford bioethicist Hank Greely told NPR.
With respect to athletic traits, though, we have no clue at this point which versions of most athleticism genes even to choose. There are the rare genes—like EPOR, or myostatin—that alone can have a significant impact on athleticism, but single genes with large impacts have proven the exception. For the foreseeable future, we cannot engineer a genetically ideal athletic specimen. A genetically perfect athlete would simply have to luck into the “right” versions of the genes for her sport.
What are the chances?
•
Alun Williams, a geneticist at Manchester Metropolitan University in England, was kept awake by that question. So he and his colleague Jonathan P. Folland combed through scientific literature for the twenty-three gene variants that have (so far) been most strongly linked to endurance talent, and then they compiled information about how frequently those gene variants occur in humans.
Some of the variants are found in more than 80 percent of people and others in fewer than 5 percent. Using the gene frequencies, Folland and Williams made statistical projections of how many “perfect” endurance athletes (people with two “correct” versions of the twenty-three genes) walk the planet.
Williams assumed that perfection—even based on the limited number of identified genes—would be uncommon. A Greg LeMond or Chrissie Wellington, after all, is a rare find. But Williams was dumbfounded when he ran the statistical algorithm on his computer and saw that the odds of any single human possessing the perfect set of gene variants was less than one in a quadrillion. To put that in perspective: If you bought twenty lottery tickets per week, you’d have a better chance of winning the Mega Millions twice in a row than of hitting that genetic jackpot. Just based on the small number of genes that Folland and Williams included, there is no genetically perfect athlete on earth. Not even close. Given the paltry seven billion people on our planet, chances are that nobody has the ideal endurance profile for more than sixteen of the twenty-three genes. Conversely, an individual is also unlikely to have very few of those endurance genes. Essentially everybody falls in or near the muddled middle, differing by only a handful of genes. It’s as if we’ve all played genetic roulette over and over, moving our chips around, winning sometimes and losing other times, all of us gravitating toward mediocrity. “We’re all relatively similar because we’re all relying on chance,” Williams says.
There are, however, certain elite athletes who do not rely on chance: Thoroughbreds. Because athletic ability involves a complex mix of genes, champion racehorses tend to result from multiple generations of mating among athletic horses. The more genes that are involved in an athletic trait, the more generations of athlete-to-athlete breeding it will likely take to get an offspring that has collected enough of the right gene variants to make the winner’s circle. The lone safe bet at the racetrack is that every top horse has racehorses not only for parents but also for grandparents and great-grandparents.
Racehorse breeders have done an outstanding job; the best Thoroughbreds run a mile in a minute and a half. Nonetheless, in many of the world’s marquee horse races, the speed of the winners plateaued decades ago. Thoroughbreds may have either reached their physiological terminal velocity or simply run out of new athleticism genes within the breeding population. (Thoroughbreds are relatively inbred, with more than half of the genes of modern racehorses tracing back to only four individual horses—the Godolphin Arabian, the Darley Arabian, the Byerley Turk, and the Curwen Bay Barb—that traveled from North Africa and the Middle East to England in the late seventeenth and early eighteenth centuries.)
As Pitsiladis put it, to be a world-beater, “you absolutely must choose your parents correctly.” He was being facetious, of course, because we can’t choose our parents. Nor do humans tend to couple with conscious knowledge of one another’s gene variants. We pair up more in the manner of a roulette ball that bounces off a few pockets before settling into one of many suitable spots. Williams suggests, hypothetically, that if humanity is to produce an athlete with more “correct” sports genes, one approach is to weight the genetic roulette ball with more lineages in which parents and grandparents are outstanding athletes and thus probably harbor a large number of good athleticism genes. Yao Ming—at 7'5", once the tallest active player in the NBA—was born from China’s tallest couple, a pair of ex–basketball players brought together by the Chinese basketball federation. As Brook Larmer writes in Operation Yao Ming: “Two generations of Yao Ming’s forebears had been singled out by authorities for their hulking physiques, and his mother and father were both drafted into the sports system against their will.” Still, the witting merger of athletes in pursuit of superstar progeny is rare.
Even that would not guarantee athletic success for any individual offspring of great athletes. In fact, the better the parents are, the less likely it is that the child will be equally good. In any trait that is influenced by many genes, it is simply statistically unlikely that a child is going to get as lucky as a very lucky parent. The phrase “regression to the mean” sprang in part from the study of height. Of course, the child of two seven-footers is very likely to be taller than average, but not likely to be as significant of an outlier as his parents. Similarly, the child of two extraordinarily gifted athletes will likely have more of the gene combinations that con
tribute to athleticism than a randomly selected person, but will be hard-pressed to get as lucky as her mother and father.
In large part, humanity will continue to rely on chance and sports will continue to provide a splendid stage for the fantastic menagerie that is human biological diversity. Amid the pageantry of the Opening Ceremony at the 2016 Olympics in Rio de Janeiro, make sure to look for the extremes of the human physique. The 4'9" gymnast beside the 310-pound shot putter who is looking up at the 6'10" basketball player whose arms are seven and a half feet from fingertip to fingertip. Or the 6'4" swimmer who strides into the Olympic stadium beside his countryman, the 5'9" miler, both men wearing the same length pants.
Our ethnic, geographic, and individual family histories have shaped the genetic information we carry at the nucleus of our every cell and, in turn, our bodies. It is breathtaking to think that, in the truest genetic sense, we are all a large family, and that the paths of our ancestors have left us so wonderfully distinct. In the very last line of his paradigm-shattering On the Origin of Species, Charles Darwin says this of his revelation that all the biological variation he sees springs from common ancestry: “. . . from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”
Because we are each unique, genetic science will continue to show that just as there is no one-size-fits-all medicine, there is no one-size-fits-all training program. If one sport or training method isn’t working, it may not be the training. It may be you, in the very deepest sense.
Don’t be afraid to try something different. Donald Thomas and Chrissie Wellington weren’t, and Usain Bolt, after all, had his heart set on cricket stardom.
In the early twentieth century, before the Big Bang of body types, physical education instructors thought the “average” body type was the perfect form for all athletic endeavors. How wrong they were! And now geneticists and physiologists are bolstering evidence that successful practice plans might be as varied as the individuals who would undertake them.
At the end of 2007, the prestigious journal Science put “human genetic variation” on its cover as the top scientific breakthrough of the year. As DNA sequencing became cheaper and faster, “researchers are finding out how truly different we are from one another,” read the cover story.
To pursue athletic improvement is to embark on a quest in search of the practice plan that suits your inimitable biology. As the HERITAGE Family Study showed, a single exercise program will produce a vast and individualized range of improvement for any particular physical trait. Wonderfully, though, even in HERITAGE there were no “nonresponders” to everything. Sure, there were subjects who saw no improvement in aerobic fitness, but perhaps their blood pressure dropped, or their cholesterol levels improved. Everyone benefits from exercise or sports practice in some unique way. To take part is a journey of self-discovery that, largely, is beyond even the illuminating reach of cutting-edge science.
As J. M. Tanner, the renowned growth expert and world-class hurdler, so elegantly put it: “Everyone has a different genotype. Therefore, for optimal development . . . everyone should have a different environment.”
Happy training.
ACKNOWLEDGMENTS
The list of those who deserve thanks is too long for this space. Fortunately, many of their names can be found throughout this book. These are the athletes, scientists, and others who shared their thoughts.
Some, like Yannis Pitsiladis, made time for dozens of interviews. When I followed him to Jamaica, Pitsiladis made sure I could be right there in the operating room as he biopsied a former Jamaican Olympian. I am a richer person for the time I’ve spent with him.
Physiologists Stephen Roth and Tim Lightfoot scrutinized the entirety of the exercise physiology descriptions in search of errors or imprecisions. Boiling down scientific descriptions while maintaining accuracy is no mean feat, and insofar as I was able to do it, I owe thanks to the patience of dozens of scientists. I also thank my fact-checker, Rebecca Sun, a budding screenwriting talent. If mistakes remain, they are my fault alone.
Every so often I came across a book that humbled me with its depth of research and originality of thought. In two such cases, the authors—J. M. Tanner and Patrick D. Cooper—had passed away. To my regret, I will never have the chance to interview them, but their hard work and liberated thinking will remain in my mind as sources of motivation and courage.
Several colleagues at Sports Illustrated deserve special thanks. Without Richard Demak, I doubt I would be writing about sports science for a living. Without Chris Hunt and Craig Neff, I doubt I would’ve had the space in SI for the story that became the seed of this book. Without Terry McDonell and Chris Stone, I doubt I would’ve had the freedom to work on this book. Without the unfailing encouragement of L. Jon Wertheim and my agent, Scott Waxman, I certainly would have stopped this book before it got started. Thank you, Scott, for foiling my attempt to back out. (Thanks to Farley Chase for work with foreign rights.)
If not for my friendship with Kevin Richards, I most likely would never have turned to sports science writing. Kevin was born in Jamaica and died in Evanston, on a track meet Saturday more than thirteen years ago. I expect that the wound will always be fresh for those of us who ran beside him. I thank Kevin’s parents, Gwendolyn and Rupert, and coach David Phillips for their strength. And Kevin Coyne, for teaching me how to write about death and a friend.
In Kenya, I could not have gained access to the places and people (and languages) that I did without Ibrahim Kinuthia, Godfrey Kiprotich, James Mwangi, and Tom and Christopher Ratcliffe. Without Ibrahim and Harun Ngatia, I might still be stuck on the side of the road between Nyahururu and Nairobi looking for a tire that freed itself and bounced over a sheep and away into the brush. (Thanks to the Kenyan children who were kind enough to pluck lug nuts from the dry grass.)
In Jamaica, I thank the University of Technology staff, and particularly Anthony Davis, director of sport, and Colin Gyles, dean of the faculty of science and sport.
In Japan, I thank Noriyuki Fuku and Eri Mikami, of the Tokyo Metropolitan Institute of Gerontology.
In Finland, I thank the Mäntyranta family, but particularly Iiris. And thanks to Elizabeth Newman for helping with phone conversations in Finnish, just as I was beginning to despair in my attempt to track down Eero Mäntyranta.
Puss och kram to my Swedish “family.” Especially Kajsa Heinemann, for her friendship in my journeys to Sweden, and also for translating Swedish articles so that I could prepare for my time with Stefan Holm.
On that note, for translation of conversations, papers, or videos, I thank Shiho Takai (Japanese), Alex Von Thun (German), and Veronika Belenkaya (Russian).
My name may be the one on the cover, but if the curtain were removed, many wizards would be visible. Thank you to the staff of the Current imprint at Penguin, particularly marketing director Will Weisser, director of publicity Allison McLean, publicist Jacquelynn Burke, and Katie Coe. I reserve special gratitude for editors Adrian Zackheim and Emily Angell. The best way to measure their belief in this project and patience with me is in words: 40,000 of them. That’s how many too long I was in the first draft. I also thank Matthew Phillips and Louise Court of Yellow Jersey Press.
Psychologist Drew Bailey’s contributions can hardly be overstated. They include tolerating discursive discussions at any time of day, helping with data analysis of NBA bodies, and acting as a personal alert system for new findings that might influence my writing. Genetic science is a moving target, and I could not have tracked it alone. (Thank you, Will Boylan-Pett, for help accessing journals.)
As far as I can tell, my father, Mark Epstein, had scant interest in genetics until I did. Now he is constantly on the lookout for genetics articles and has even had bits of his own genome tested. What greater example can a father provide? My sister, Charna, and brother, Daniel, probably heard “I don’t think I can do this” mo
re times than I care to recall. They never believed me. My mother, Eve Epstein, seems always to have known I would write a book. In addition to her help with Swedish translation, her encouragement sustained me. In the course of working on this book, I came across a letter sent from a music teacher to my mother’s parents—both of whom fled Germany—when my mother was seven. It reads:
I wish to report to you that your daughter is doing exceptional work for the amount of time I have been able to give her. She has an unusual high musical IQ and deserves an expert to give her special attention. I do not have more than a scattered few minutes to show her any special attention and this worries me. In this past twenty years of meeting and working with children, I have never encountered a more alert, exceptional child than Eve. Possibly we could talk it over soon.
Sincerely yours,
Howard Baker
It is a reminder that the requisite nature and nurture are nothing without one another.
Lastly, thank you, Elizabeth. I like to joke to myself that the high pain tolerance of MC1R gene mutants must explain her threshold for my antics. If I ever write another book, I’m sure that one will be dedicated to her too.
NOTES AND SELECTED CITATIONS
The page numbers on these notes refer to the printed version of this book. The link provided will take you to the beginning of that print page. You may need to scroll forward from that location to find the corresponding note reference on your e-reader.
The reporting of this book included hundreds of interviews. In many instances, the interviewees are quoted directly, making the source of that information obvious. In a few cases, high-performance scientists shared with me their data from elite athletes, but asked not to be named, citing the fact that the work is conducted for the purposes of gaining a competitive advantage for a particular team or athlete. Because I do not name scientists or athletes in such cases, I used their data strictly as supporting information for other work.
The Sports Gene: Inside the Science of Extraordinary Athletic Performance Page 31
