Long before he co-authored on Lance Armstrong or introduced the phrase into the lexicon with his feature on Ray Lewis鈥檚 dealings with some hucksters, Sports Illustrated senior writer David Epstein had questions about the biology behind elite athletic performance.

In high school he wondered why the mini-diaspora of Jamaican runners that populated his team would blow away the competition despite, 鈥渟ome of these guys not showing up to practice that much,鈥 he says. As a member of the track team at Columbia University (Epstein ran the 800m), more questions came. Epstein observed that despite starting the season slower than most runners, he responded better to training, even though he and his teammates trained stride-for-stride. Then, when he arrived at meets, he learned that the competition in distance events wasn鈥檛 merely from Kenyans, they were mostly from the same rural tribe, the Kalenjin.
His observations of nature鈥檚 influence on athleticism seemed to contradict the nurture-based , popularized by Malcolm Gladwell. Epstein saw the rule influence not only popular culture, but academia as well. He wanted to investigate the long-standing nature versus nurture debate among elite competitors, so he travelled the world, interviewing athletes, scientists, and coaches in search of some answers.
国产吃瓜黑料 recently caught up with him to talk about his new book, The Sports Gene: Inside the Science Of Extraordinary Athletic Performance ($26.95; Current Hardcover):听
Do you find there鈥檚 a misconception about genetics in the general public?
The problem is that, when a gene comes out, the media will say, 鈥淥h, you have the fat gene or the angry gene or the promiscuous gene.鈥 First of all, sometimes the results are not repeated and they get blown out of the water later. Other times, they have a tiny effect. It鈥檚 like trying to say you have the whole puzzle when you have one of a thousand pieces, with some of those other pieces being not genes but environment. So I could see why people would say, 鈥測ou have the brain damage gene, you鈥檙e going to have dementia.鈥 It just tells you that you鈥檙e at increased risk.
听Some genes are deterministic, the ones that makes us like other humans. Brain chemicals, our organs, 10 fingers鈥攊t takes a pretty major mutation to change those. Then there are others like for Huntington鈥檚 where if you have the gene, you have the disease, but most genes are predisposition and not destiny, and that nuance gets lost.
听It seems like the problems come when we graft narrative onto a subject we don鈥檛 fully understand, but want to delude ourselves into thinking we do.
That definitely happens. We fit narrative to what we can see. We can鈥檛 see our genes. All we can see are the things we can come up with so we fit narratives whether we can see all the evidence or not. For my training partner at Columbia and me, I now know that I have genes that make me a higher responder to training. I could see that my teammate鈥攚ho unlike me was pegged as naturally talented鈥攚ould start the season in way better shape, but with training I would surpass him. People would tell me how tough I am. And he was told he had a lot of talent, but had he had psychological problems or something. No, we were doing the exact same training. But you fit a narrative to what you can see. There鈥檚 this twins study I found where two twins were separated at birth and found out about each other as adults and they were both obsessive about being neat and clean. One of them said in an interview that his adoptive mother was really neat, so he learned from her. The other said his adoptive mother was a slob and he never wanted to be like her. Ok, so maybe it鈥檚 actually that there鈥檚 a genetic inclination to behave that way and they fit it to a narrative that works that way, and it happens a lot in sports.
The popular narrative you found while researching the book was the 10,000-hour rule made famous by Malcolm Gladwell鈥檚 book Outliers. Was the idea that pervasive?
Totally. And it motivated me to do the book, actually, and this was before I even knew how I felt about the so-called rule. I didn鈥檛 know about the science, but I wanted to evaluate it. And it took a long time and a lot of self-doubt before I became confident that I was interpreting it correctly. It was popping up everywhere. When I would go to the American College of Sports Medicine conference, there wasn鈥檛 a day that went by that people weren鈥檛 using it in their talks.
I remember writing a story about brain trauma at Purdue and watching video of a hit LaDainian Tomlinson took. He fell on his head and these scientists said, 鈥淲ow, he should have broken his neck. That鈥檚 your 10,000 hours there. That guy has put in his time of taking hits and a normal person would have broken their neck.鈥 And I thought, 鈥淪eriously, we鈥檙e going to use this everywhere?鈥 I talked to Olympic scientists a lot and they didn鈥檛 seem to think about the science or have even read they underlying paper. They knew nothing about it. The study is based on the practice hours of 10 people who are already in a world-famous music academy, so they鈥檙e already prescreened. When you take a study and you already screen out most of the gene pool, it鈥檚 not a very representative sample.
And people would call it 鈥淕ladwell鈥檚 10,000 hours鈥 as if he had done the research for it. It started to bug me. People were using it just to mean that practice was important, that鈥檚 it. That鈥檚 not what the theory says. The researcher behind it, Anders Ericsson, has said that he thinks all people have the necessary genes to be elite performers. Just saying that practice is important is totally uncontroversial. From a scientific standpoint it鈥檚 useless. Scientists have to say how important it is, what else is important? I found it to be troubling from a scientific standpoint and the more I evaluated it, the more it seemed to unravel. And ultimately, Ericsson read Outliers and said Gladwell misconstrued his work. His words, not mine.
How did Gladwell misconstrue it?
Aside from not having copied the numbers from the actual paper correctly for his book? He says that there is a perfect correspondence between practice and the level of expertise a person attains. And you can鈥檛 tell that from the paper. The 10,000 hours is an average of differences. You could have two people in any endeavor and one person took 0 hours and another took 20,000 hours, which is something like what happened with two high jumpers I discuss in the book. One guy put in 20,000 and one put in 0, so there鈥檚 your average of 10,000 hours, but that tells you nothing about an individual.
Now, Gladwell doesn鈥檛 say there鈥檚 no such thing as genetic talent. I think other writers are stricter than him. [Matthew Syed鈥檚] Bounce is a book that minimizes talent. Gladwell does say elite performers are more talented. One of the things that Ericsson criticizes Gladwell about is to say that 10,000 hours is some kind of rule. The paper just says that these performers by the age of 20, these performers have accumulated 10,000 hours but there鈥檚 no where that says it鈥檚 a magical number where that鈥檚 when they become elite or anything like that. These people, by the time they go into their professional careers, have way more than that. That鈥檚 just where they were when they鈥檙e 20 as an average, not even to mention their individual differences.
Tracking chess masters helped you dismantle the rule, because it wasn鈥檛 so restrictive in its sample size, right?
Even with chess masters you鈥檙e talking about a population that鈥檚 pretty trained. So you鈥檙e still eliminating a large swath of humanity before you even start. Researchers found it takes 11,053 hours on average to achieve international master status. But the range there is what鈥檚 important. One guy takes 3,000 hours to become a master and another takes 25,000 and he鈥檚 still not there. So you can average those and come up with some rule, but it doesn鈥檛 tell you anything. You can always average individual differences and come up with some sort of a rule. Gladwell does leave more room for elite talent. He says, 鈥淢ichael Jordan has more talent than me, but he also put in the work.鈥 And that鈥檚 uncontroversial, that someone is talented and put in work. Beyond the chess players, genetics is continually finding now that one person鈥檚 hour of practice isn鈥檛 as good as the next person鈥檚 hour. Talent isn鈥檛 something preceding you trying something, but your biological setup that allows you to benefit more than the next guy.
That鈥檚 one of the most fascinating and unexpected parts of the book, where you discuss the Heritage study鈥檚 findings on trainability. Explain its implications.
That鈥檚 the most famous exercise-genetics study ever done. It鈥檚 the collaboration of five colleges in the U.S. and Canada. They took sedentary, two-generation families, which didn鈥檛 have a training history, and put them through stationary-bike exercise plans that were totally controlled. Families had to go into the lab and exercise over five months. The goal was to see how people would improve, and they were split into four different university centers to do the training and every center saw the exact same pattern. About 15% of people improved their aerobic capacity very little or not at all. And 15% improved 50% or more doing identical training. Families tended to stick together in the improvement curve, so about half of any person鈥檚 improvement was determined by their parents. I remember the editorial that ran in the journal of applied physiology 鈥渟ome people鈥檚 alphabet soup鈥攎eaning their DNA鈥攄idn鈥檛 spell 鈥榬unner.鈥欌 One person training the exact same as another person can have completely different outcomes.
What does that mean for the athlete who has plateaued?
No cookie-cutter training plan is ever going to work. I鈥檓 a great example. Before my senior year of high school, I got up to 85 miles per week of training, which isn鈥檛 a lot for a pro, but was a lot for someone my age. When I came to college, I really got interested in physiology and took a scientific approach to my training. I found I was better at cross-country by training 35 miles per week with hill intervals instead of doing 85 miles per week. People need to pay attention to their training plans, because if something is not working for you as well as the next guy, it may be your biology, so you should try another plan. If you鈥檙e not taking a trial-and-error approach to training where you鈥檙e measuring something your time, you鈥檙e way less likely to find a plan that works for you. The cookie cutter approach to training is purely a facet of having a large group of people to train. If you鈥檙e writing a training book, then you have to be more broad. In the book, there鈥檚 a Danish scientist who biopsies his athletes and he鈥檚 found guys with huge fast twitch muscles and he tells them, 鈥淵ou鈥檙e working out too much because you鈥檙e causing your fast twitch muscles to take on the properties of more endurance muscle fibers.鈥
That can be tough for coaches, especially of big teams, because making everyone train the same way is seen as being fair to all the players.
I think my high-school coach noticed this about me, because when I graduated he said, 鈥淕et them to train you like a sprinter when you go to college.鈥 And I did, and I got better at every distance by doing short training. I think part of the genius of Usain Bolt is that if you read his biography, 9.58, he talks about how lazy he is and he likes his coach because his coach realizes he won鈥檛 show up for practice some days. Who knows what his proportion of fast-twitch muscle fibers, but probably it鈥檚 huge. Those guys get hurt if they train too much, or they convert their super-fast-twitch muscle fibers into normal fast twitch. They take on the properties of endurance muscle fibers. Bolt will ramp up to peak when he needs too. For some guys, less training is the best medicine.
It鈥檚 like the anti-10,000-Hour Rule鈥攚orking out too much can negatively affect some athletes?
It鈥檚 great that the 10,000-Hour Rule emphasizes the importance of practice because some people underestimate what practice can do. I think I can take anyone with two working legs and in six months can get them to run a marathon. I think most people don鈥檛 believe they can do that, but they can. It鈥檚 cool that they emphasize how much practice can do, but kids are getting burned out and injured from overtraining. It鈥檚 especially true for guys that have a lot of fast twitch, who are shown to be more prone to getting hurt. Usain Bolt has figured it out. He trusts himself to take time off.
A lack of nuance can really make it difficult to talk about genetics, especially with race.
Writing about race almost scared me out of writing the book altogether, which is why I wrote a section that had nothing to do sports on whether race had a genetic meaning in the first place. I was hoping that would be a non-hysterical way to start the discussion of genetics. But I wasn鈥檛 alone. Some scientists told me that they had data on physical differences in some ethnic traits that they were not going to publish. They were worried about reinforcing stereotypes or that people would take this to mean they鈥檇 also be somehow implying that there are innate intellectual differences between ethnicities; never mind that their work had nothing to do with that. But that鈥檚 the fear. So there鈥檚 clearly a political aspect to science that people are angling for depending on what social message they want to convey, but that social message has no bearing on the truth. The best way to get the best outcome for all people is to figure out what ethnic differences are real and what are not. Once I heard scientists tell me鈥攊t wasn鈥檛 often, but it did happen鈥攖hat they were holding back data, I decided I didn鈥檛 what to hold back with things that I found.
Black athletes have been so negatively impacted by pseudoscience stereotypes about what鈥檚 biologically innate to them that it鈥檚 easy to distrust any discussion of what is innate ability. Writers like William C. Rhoden of the New York Times want scrap the idea of athletic prowess鈥攇ood or bad鈥攂eing innate, chalking up differences in race and ethnicities as social constructs. You cite an example of that in the book.
Rhoden says that white cornerbacks are shuffled off to safety instead of playing corner because whites are stereotyped as slow. I didn鈥檛 know if he was right or wrong. The only way I thought I could evaluate was to look at combine times to see if anyone who had the speed to be a corner but were shuffled off to safety. What I found was that there weren鈥檛 safeties of any ethnicity that were running fast enough, most of the time, to be cornerbacks. There certainly are social constructs and bigotry, but people attack those ideas thinking that will negate the bigotry. I think those pseudoscience beliefs are the result, not the cause, of bigotry. People aren鈥檛 looking at innate differences and decide, 鈥淲ell, I guess I鈥檓 going to be racist.鈥 Patrick Cooper addresses that in his research in his book Black Superman, when he dismantles the incorrect idea that physical prowess and intellectual prowess are on some sort of teeter-totter. That was never even an idea until physical prowess became associated with African Americans in the 1930s. So, I understand why it鈥檚 important to be critical of those ideas about innate ability.
But you believe there are innate differences between ethnicities and that we need to be up front about them?
In medicine, this is a non-issue. There was a study this month that come out showing tuberculosis measurements should be tailored by ethnicity because people with African ancestries, their immune systems respond differently to treatment. So you monitor the disease differently. We know that people with African ancestry have lower hemoglobin levels so sometimes they get turned away inappropriately from blood donation because they get measured against European standards. It鈥檚 really important to acknowledge ethnic differences in those cases. What the problem is when you take generalities and you apply them to an individual. A stereotype is a way to evaluate someone indirectly. When you can have someone at the NFL Combine, it makes no sense to evaluate him indirectly with a stereotype when you can evaluate him directly and decide whether he鈥檚 good or not.
Michael Johnson believes that the slave trade bred exceptional black athletes, especially sprinters from Jamaica. Is that a theory where pseudoscience is rearing its head?
You would definitely want to see more work to be conclusive about it. Yannis Pitsiladis [researcher from the University of Glasgow] is the only guy killing himself to do that work to figure it out and there鈥檚 only so much of that that he鈥檚 gotten done. There have been theories on other traits beside athleticism that the 鈥渦nnatural selection鈥 of slavery selected for certain traits and some of those have really fallen by the wayside, even though they seemed intuitively right. The slave theory might make sense, but the science doesn鈥檛 support it right now. Maybe when genetic testing changes, we鈥檒l see something different, but I want to highlight where the science is now. So far the genetic data is suggesting that while every man who has been in the Olympic 100 meter final is of sub-Saharan West African descent, they come from a variety of countries and variety ethnic groups. There isn鈥檛 some genetic monolith for sprinting in Jamaica or the Caribbean. I think we鈥檇 see a lot more really good sprinters from West Africa if there were some sports infrastructure in those countries.
You mention the Jamaican coach in the book that鈥檚 wary of sending sprinters to the US for college because of the risk of overtraining.
When I went to Champs, the national high-school track championships in Jamaica, and I talked to coaches about their training plans, their kids who are the equivalent of our freshmen and sophomores only practice two to three days a week. They take it easy on them until they become upper classmen. When I was a freshman, we started to lift weights right away. They don鈥檛 let them lift weights until they鈥檙e at least 16. The underclassmen were training way lighter than what you鈥檇 find at decent high school in the U.S. Their approach seems to be one of the keys to developing to sprinters on the island. That coach still thinks most sprinters should go to college in the US, because they鈥檙e not going to make money off of running, so they should get a scholarship and college degree out of it. But the guys at the top, they should stay on the island because they don鈥檛 over race them there.
But when you see a cluster of high-level athletes from one location, does that raise red flags that the phenomenon we鈥檙e witnessing is just the result of PEDs?
I鈥檝e been involved in reporting on doping. You鈥檇 be na茂ve not to wonder about it and Jamaica鈥檚 testing is getting more rigid and we鈥檙e going to find out. But when I look at their high-school times, like what they do at Champs and the number of good runners they send to the U.S., who are then subject to the same kind of testing that the U.S. has鈥擨 don鈥檛 think PEDs are driving the phenomenon overall, but I鈥檓 quite sure there are athletes are doping.
Which brings us to a really unexpected theme to this book: It鈥檚 secretly an economics and social science book as well as a genetic science one. The 10,000-hours faction believes in nurture over nature. You show the intersection of genes, training, economic incentives, and cultural institutions that create athletes. Nature and nurture together.
Usain Bolt is a great example. He was 6鈥4鈥 when he was 15 years old and blazing fast. He wanted to play soccer or cricket. What are the chances anyone lets him run track in the U.S.? To me, it鈥檚 zero. There鈥檚 no way he鈥檚 not playing basketball or football. Nowhere but Trinidad, the Bahamas, Barbados, and Jamaica would a guy that鈥檚 6鈥4鈥, with blinding speed, be allowed to run track instead of something else. People have asked me, 鈥淪hould we do genetic screening for the best athletes or at least some sort of measurements?鈥 Yes, measuring kids and trying to fit them into the right sport for their body type absolutely works. That鈥檚 why you saw Australia and Great Britain up their medal haul with their talent search programs when they had their Olympics. However, when there鈥檚 a sport that鈥檚 most popular in an area, you don鈥檛 have to do that because you already have the natural sifting program. You don鈥檛 have to go hunt for the best football players in America because they鈥檙e already going to go play football and then we select them.
Sprinting in Jamaica is like our system here for college football. What are the chances that a really good high school football player will fall through the cracks and not go to college? Pretty small, because people are looking for them and they earn adoration and accolades from performing well. That鈥檚 the way it is for youth track in Jamaica. They have shady boosters and everything! I went to a warm up track at Champs and started to ask the coaches about recruiting and how it works and they kept telling me, 鈥淲e鈥檙e not allowed to give refrigerators to their parents.鈥 I鈥檓 like, 鈥淲hat?!?鈥 Apparently there was a rash of bribing kids with fridges to get kids to come to their track high schools. In Kenya, there鈥檚 no joggers. There鈥檚 only people who are running for transportation, people who are absolutely killing themselves in training to be Olympians and pros and people who aren鈥檛 running at all. There are no opportunity costs.
There was a guy named Brian Sell, he was [a marathoner] on the US Olympic team in 2008. He put in a lot of work, he got really good, he made the team, and he was putting off dental school. He was putting off making a living to chase being a pro runner. In rural Kenya, where the Kalenjin are from, there is no opportunity costs for attempting to be a runner. You鈥檙e not putting off any other opportunity, so you might as well try, so you get this huge input in the talent funnel. All of them try to train like Olympians. They go down to the local dirt track and guys who have a gold medal or world championship are already there and they literally try to run right alongside them right away. Most of them fall by the wayside, but the ones who survive are world-beaters. It鈥檚 a pretty good talent system.
But it鈥檚 not all economics and social systems for Kenyans. I mean, can a person with cankles win the NYC marathon?
It鈥檚 interesting. Americans think that Kenyans are good runners. Kenyans aren鈥檛 good runners; the subset of people from the Kalenjin tribe are the amazing runners. They run to school and I think that primes them for training and serves as a talent selection mechanism. But millions of kids run to school all over Africa and in India, and most of the great runners come out of the Kalenjin, so that environment is not unique to the Kalenjin. The Kalenjin have this incredibly narrow build, with a very narrow pelvic girdle and long, thin limbs. That鈥檚 a result of having your ancestry in a hot, dry climate. The more surface area you have relative to volume, the more heat you unload through the surface. Also, the less weight you have further from your center of gravity, the easier it is to swing your legs. So your running economy is better. Oscar Pistorius鈥 running economy is as good as an elite marathoner, which is unheard of for a sprinter, because he has these artificially light lower limbs. The lighter the lower your limbs, the better pace you can go for a given amount of oxygen. Some of the cool studies that have confirmed this is they take runners and put 8 lbs on their waist and it increases how much oxygen they have to use a little bit when they run at a certain pace. But if they take that same 8 lbs and put it around each ankle, so it鈥檚 4 lbs each ankle, it鈥檚 a 20% difference in the amount of energy they have to use to go the same pace. Weight at the end of your limb makes it hard to swing your legs, which makes your running economy much worse. So you want as long and as thin a leg as humanly possible. That鈥檚 the build Kalenjin have. A study showed that even untrained Kalenjin have better economy than untrained Danish kids. Some of the Danish kids had better aerobic capacity, meaning they鈥檙e in better shape, but they still had worse running economy because their lower legs are thicker, so if you have thick lower legs, you鈥檙e not winning the NYC Marathon, unfortunately.
DAMN YOU FOR CRUSHING MY DREAMS.
Sorry.
What you鈥檙e saying does give some credence to the minimalist shoe craze, right?
Dan Lieberman, a scientist who did some of the famous work on barefoot running featured in Born To Run has done some work where he will have people run in shoes and then have them run with an equivalent weight strapped to the top of their foot. They鈥檙e running barefoot, but they still have the weight of a shoe and their running economy is worse. So you definitely want to stay light down there.
What you explained about the Kalenjin, is part of a larger trend in sports spurred by economics, which you describe as the Big Bang of Body Types.
Athletes in sports where they have to be big have gotten even bigger and where they have to be small have gotten smaller. For instance female gymnasts have gone from an average height of 5鈥3鈥 to 4鈥9鈥. Two things happened. For a while there Germans were leaders in athletic science and there was the idea that the average body type would be best for every athletic endeavor鈥擵itruvian man. That turned out to be woefully wrong. So once that science receded and scientists realized specialized body types were better. But also as the reward pyramid became really narrow. There used to be vibrant club systems that would support semi-pro and lower level pros, especially in Europe, because if you wanted to see sports, you had to go in person or participate. Then you get TV contracts and revenue sharing with athletes where they start to be able to make a huge living and so many more people want to be pro athletes. Now everyone has a ticket to the Super Bowl, basically, by watching on TV. You expand the consumer population enormously and make the rewards tremendous, but concentrated at the tiny pinnacle of performance. As those trends happened over the 20th century it caused people who wanted to be professional athletes to try, which put more people in the talent funnel and the most specialized and best bodies for those sports were coming out the bottom. General managers and scouts started searching farther and wider as the money became bigger. One of the places that showed up was as soon as you have revenue sharing with players in the NBA, the percent of the league that鈥檚 made up of 7-footers doubled almost over night. Everyone wants to be in the NBA and teams started going abroad to find guys with height when they ran out of guys at home.
That explains why the high jump record isn鈥檛 being challenged anymore. The economic incentive to attract a big talent pool has gone away.
For the most part no one gets close. Even in the 100-meters, you鈥檝e got Bolt, basically. There are guys in the finals of the 100 of the Olympics who probably aren鈥檛 making that good of a living. Trindon Holliday, now an NFL player, he may have been the best young sprinter in America at one point. He beat Walter Dix, who medaled in the 100m in Beijing, in the US Championships in 2007, but declined to go to the World Championships because he didn鈥檛 want to miss any LSU preseason football. There鈥檚 a guy who could become America鈥檚 best sprinter, but doesn鈥檛 even want to miss a day of preseason football.
Are you afraid that genetic breakthroughs will be abused by athletes?
One of the interesting things was any researchers I鈥檇 talk to who had discovered a gene that had an impact on muscle growth, when they published their findings, they鈥檇 get deluged by weightlifters and athletes who volunteer themselves. So that possibility exists. There was a trial of a German track coach and in the trial it became clear he was trying to get his hands on a gene therapy to increase the body鈥檚 production of red blood cells.
There鈥檚 a guy who I write about in the book who has a mutation on his EPO receptor gene that causes him to overproduce red blood cells. Look at what EPO did to cycling. You think if they could tinker with their EPO receptor gene they wouldn鈥檛 do it? However, I think if I were an athlete who was hell-bent on cheating, current forms of doping like microdosing testosterone and re-infusing their own blood are so effective that I wouldn鈥檛 even bother with something that could kill me. But I think that time will come where things will be made safer and then will people pick the traits of their children and that鈥檚 a little scary because we haven鈥檛 had discussions about how to regulate and deal with that. I fear it鈥檚 going to come faster than we can think about it.
So, what鈥檚 the next big breakthrough?
One of the coolest things is genetically tailored diet and training. It won鈥檛 be perfect because we still don鈥檛 know what most genes do. But exercise genetics will potentially produce some of the most widely used and effective medicine. You may be able to tell people how they can train to get a certain health benefit instead of taking a drug, or maybe that they can鈥檛 get that benefit with training so they do need a medication. Also, injury predisposition genes are coming online right now. It would be nice to know more than just through straight trial and error what鈥檚 the best training for your and how you can avoid injury. For example, what if you have a predisposition to low collagen production, so now we know to keep you healthy we have -to strengthen your support muscles more than the next guy. Of course, with the concussion crisis, there鈥檚 clearly a gene that predisposes people to sustaining more damage from getting hit in the head than other people and I think it鈥檚 crazy that testing for it is not in wider use. I understand the fears of it going into wider use, but this isn鈥檛 a place where you should be hiding from any information. Even though it鈥檚 just statistical info, it鈥檚 not destiny to have a gene.