David Epstein is the New York Times bestselling author of The Sports Gene, an investigative journalist, and a long time contributor for Sports Illustrated where he co-authored the 2009 report that Yankees third baseman Alex Rodriguez had used steroids. He has also been a crime writer, has lived in the Sonoran desert, on a ship in the Pacific Ocean, and in the Arctic. Fortunately, it was in Soho, New York City that I was able to meet up with him where we talked about the intersection of sports and genetics, the physiology of elite athletes, why Kenyans are such great marathon runners, Belgian Blue cattle, the origins of cognitive ability, and how to find the world’s best fighter pilots or bob sled drivers.
Mike Walsh: I'm here today with David Epstein. We're in New York, although David and I actually met in Istanbul when we were both speaking there a few weeks ago.
David Epstein: Yeah, we did. It was a lot of fun.
Mike Walsh: We're here to talk a little about some of David's work in sports, and his book that came out a couple of years ago, and some of the ideas he's thinking about now. David, can you take us through just a little bit about the premise behind The Sports Gene?
David Epstein:Sure. I guess the dirty secret of The Sports Gene was that it was really 15 of my own deepest questions about the nature/nurture of sports performance and skill acquisition in general, and what the balance between nature vs nurture is when it comes to high performance athletics.
I really wanted to delve into that and try to take a look at everything we've learned in the decades since the sequencing of the human genome. What have we learned about the balance of nature, nurture and athleticism? Because usually it's just people arguing their intuition, and I wanted to take these questions as far as I could, as far as science has taken them so far.
Mike Walsh: One of the really fascinating ideas in your book, was that when you look at an organized competition, what it really shows you is the diversity of human genetics.
David Epstein: That's right. The way I got interested in that topic was because I noticed that there was this group of sport psychologists who were saying, "Athletes have gotten so much better in recent decades. Their genes haven't evolved in that time, so it must just be practice." I'd seen a lot of data about how body types had been changing in sports, and I said, "Their genes absolutely have been changing, not in the population as a whole but within each sport."
In fact, in the early half of the 20th century, sports science was dominated by German sports science that had these particular racial agendas. You would see in some of their papers they would use the phrase "the perfect form of man," which meant only a man, only a white man, and one that was medium height and medium weight. That would be the best for everything, the believed, a kind of an average prototype. That started to go away in favor of more rigorous science that showed that very specific types of bodies are perfect for different sports.
The average elite high jumper and elite shot putter, for example, were once the exact same size. Today, the average elite shot putter is two and half inches taller, and 130 pounds heavier. The bodies have gotten much more specific to their niches.
Mike Walsh: What's changed? Is it our selection process?
David Epstein: It's the selection process, so first sports went global.
Mike Walsh: Right.
David Epstein:Like in the filtering system. There are a couple of things. One, there's been what's called a super star effect. Previously, earlier in the 20th century, most athletes were part of European clubs that had amateurs, and families, and also supported these kind of low level pros and semi-pros.
That went away with the digital revolution. First you get radio, then television, the internet. Suddenly, instead of most people being kind of amateur athletes and some spectators, many more people became remote control athletes, spectators, and then all of the fame and financial rewards tipped toward these tiny people at the very, very top. Most people became spectators.
Mike Walsh: Right.
David Epstein: So instead of consuming the performances of your local athlete, everybody can go see Michael Jordan now.
Mike Walsh: It becomes a winner takes all game.
David Epstein: Exactly. Far fewer people were in sports, but the talent search became incredible. What happened to athletes' bodies then is wild.
In sports where height is prized, tall athletes got taller. When the NBA went global with television and made players partners in the league where they could get a share of ticket revenues and television contracts, literally in one season the proportion of men in the NBA who were seven feet tall more than doubled from 5 percent to 11 percent. This global search happened in like a year.
Today, if you know an American man between the ages of 20 and 40 who's at least seven feet tall, there's a 17 percent chance he's a current NBA player (I got all this data to do the analysis for my book). Not only that, but my arm span is exactly equal to my height, like Leonardo Da Vinci's Vitruvian Man. The average in the NBA is about six foot six and three-quarters height, seven-foot-long arms is the average. They're incredibly strange. This has happened in all levels of sports.
The average elite female gymnast shrunk from five foot three to four foot nine in the last 30 years. It makes for lower inertia, so that they can spin better. If you plot on a graph the changes in body types of all different sports in the last 100 years, they're all going away from one another. The tall athletes are getting taller, the small smaller, and all these micro changes in the ratio of bones. The Australian scientists who plotted this noticed that it looked like the charts showing the universe, the galaxies flying away from one another, so they call it The Big Bang Of Body Types that occurred once sports became more of a consumer thing than a participatory one.
Mike Walsh: It's like a hyper form of natural selection.
David Epstein: Absolutely. The gene pool in competitive sports absolutely has changed. There are studies looking at water polo players, for example. The length of their forearms in relation to their total arms has gotten longer because it makes for more forceful throwing. The opposite for rowers, because having a short forearm compared to your total arm makes it easy for pulling.
Mike Walsh: It's quite intuitive to think that certain body types are good at certain types of sports, but where does this actually come from? You previously told me one story about why Jamaicans are such fast runners. What is it about some of the way our DNA is set up that makes us good at sports or good at being trained?
David Epstein: Those are really big questions. One of the reasons I got into this area was I grew up in an area with a lot of Jamaican immigrants. Track and field was really popular at my high school. I got interested in Jamaica, and when I was like 15 or 16, I opened up an atlas and saw that it was an island of two and a half million people, and I started to wonder. My high school track team had won our conference championship 24 years in a row. I'm like, "What's going on in Jamaica?"
Then in college I moved up to be a long distance runner. Now I'm meeting these Kenyan guys and learning not only are they Kenyan, they're all from one minority tribe in one town in Kenya. I'm like, "Okay, what the heck's going on over there?"
Mike Walsh: Like, what were they feeding them?
David Epstein: Exactly, so I went there...
Mike Walsh: You went to Kenya?
David Epstein: Yeah, I spent a bunch of time in Kenya. I had to get in really good shape, because the easiest way to interview people is to run with them at 9,000 feet. We think of Kenyans as being great marathoners, right? The New York Marathon comes, all these Kenyan guys are in front. But you go to Kenya, they think of the Kalenjin men and women as being great marathoners. It's a minority tribe that makes up about 12 percent of the population in the Western Rift Valley of Kenya.
To put their achievement into perspective, there are 17 American men and 14 Brits in history who have run faster than two hours and 10 minutes in the marathon. That's 4:58 per mile pace. Thirty-two Kalenjin men did that just in the October before my book was published. In one single month, more than all of history combined or almost double the United States. There's a couple things going on there. It's a perfect nature/nurture storm.
For one, the Kalenjin have their ancestry at an incredibly low latitude, in a hot and dry climate. When I was visiting them, I was zig-zagging over the equator to their training sites. An evolutionary adaptation to evolving in that environment is extremely long limbs compared to your body size. It's the same reason that a radiator has coils, to increase the surface area compared to the volume to let heat out effectively.
They have unbelievably long and thin limbs. It's called distal elongation. They have very little weight. They have long legs with very little weight to the extremity. The leg is like a pendulum, so it makes it very energy efficient to swing. There are shoe companies that have done studies where they put say eight pounds of weight on someone's waist when they're running, and that increases the amount of energy they need to use about one percent to go a given pace. If you take that eight pounds and put it as four-pound weights around their ankle it increases it 18 percent. The farther away it is from your center of gravity, the tougher it is.
Mike Walsh: They're like Giacometti sculptures.
David Epstein: They are. Running at a given speed, they use less oxygen to do it. On average, they have this physiology that's very conducive to endurance running, and then they have this environment where there is literally no opportunity cost to train like an Olympian. You can show up at what they call the stadium, which is literally a 400-meter oval of dirt overhanging the Rift Valley and there's sheep grazing on the infield. You'll go, and there'll be Olympians and gold medalists training, and then some guy will walk off the Shamba, which is like a subsistence farm, and just run a lap or two with a gold medalist.
They also have this incredible mentality. The guy who holds the world record in the marathon right now at a little under two hours and three minutes is a Kalenjin guy. He had not run until he was 26 and another marathoner in Kenya said, "You look like you could run. Why don't you come train with me?" Can you imagine if you said that to an American at 26? "You look like you could run. Come train with me. I'm a world champion in the marathon." Instead the guy was like, "Okay," and three years later he's the world record holder. That is physiology combined with this "it's never too late" mentality.
Mike Walsh: In this global search for genetic diversity, what role does training play? Can you have any hope against these people who have been naturally bred for superstardom?
David Epstein: It's a good question.Part of their secret is that they have so many people training so hard. Every once in a while I'll see some data from people who are overweight who actually have a very strong cardiovascular system, but they're never going to be elite marathoners because they're never going to figure it out, because they're overweight.
Here you have people who have high levels of physical activity. They can start training more easily, because they're not overweight. There's no joggers in Kenya. There's people who are running to get somewhere for transportation, there are people who are killing themselves in training to be an Olympian or a pro, and anyone else who's running is an idiot. Or a tourist.
Mike Walsh: It's just the mad dogs and Englishmen out in the noonday sun.
David Epstein: They have this mentality that they'll train incredibly hard. If the Western Rift Valley of Kenya became Finland, economically, tomorrow, gone. Running phenomenon, gone. I think it's this combination of nature and nurture. That body type is not exclusive to the Kalenjin. The best American marathoners have it too. It's just very, very common and concentrated in that population that's like the size of Atlanta and produces almost all of the worlds' best marathoners.
Mike Walsh: I think one of the interesting things that you write and talk about is that if you can identify what your own natural capabilities are, you can adapt a training program to it. Is this is something that you experienced yourself as a runner?
David Epstein: Very much so. One of the revolutionary ideas, probably the most revolutionary idea coming out of exercise genetics is the same as some of what's come out of medical genetics. Which is that I might need three Tylenol while you only need one, because we have different genes involving acetaminophen metabolism. Or maybe Tylenol doesn't work for me at all.
Mike Walsh: It's all personalized medicine.
David Epstein: Right, and obviously it's been a hard road to figure out some of the specifics, but it's looking like the same thing occurs for the medicine of training. No two people respond to any kind of training the same, because their genes mediate the improvement.
For me, I had this incredible experience where I was not a good runner and did a bunch of physiological testing and realized that my physiology was a little different than a lot of my peers. Eventually, I had genetic testing and was able to tailor my training in a way that worked for me. I experienced frustration before that. "I'm doing what other people are doing. Why isn't it working the same for me?"
How many people say that about their diet or their exercise plan? I think the lack of an ability to tailor really keeps the diet and exercise fad in business, because nothing works for everybody. People can do the same identical training and have 100 percent difference in their improvements in mitochondria or their ability to move oxygen. Sometimes that's because of them, in the deepest sense, not the training.
Mike Walsh: Is this happening today with elite athletes? Are they doing DNA and genetic testing to work out their predisposition to certain types of training?
David Epstein: They're doing some of that, but in most cases they shouldn't because the physiology testing, which still tells you a lot about your genes, also tells you things about how you've developed in your environment. That's even better.
Mike Walsh: Are you talking about phrenology?
David Epstein: Ha, yeah. I got a call from Uzbekistan's Olympic Committee about doing genetic testing. I'm like, "Don't do it. You're testing for all these genes that have something to do with the kind of muscle fibers people have. Just look at the muscle fibers directly." I was trying to tell them, it's like looking for what height gene someone has when you can use a tape measure. A tape measure is still going to tell you something about their genetics, but it's also going to tell you exactly what you want to know.
In some cases measuring genes tells you indirectly something that you can measure directly. In some cases the genes are worthwhile, especially when it comes to things like the ability to overcome brain trauma, which is a huge issue in American football now. We now know that some people don't get over it or are much more predisposed to having permanent damage.
Mike Walsh: So they should do boxing?
David Epstein: Yeah, right. They should retire very early. This tailoring of training to physiology is absolutely happening. Soccer, for example, if you look at old studies in soccer players you'll see there's actually, strangely, a shift towards slow-twitch muscle fibers, the endurance kind. Which is unusual, because in the forwards you want explosiveness, but it turned out they were training everyone the same. The midfielders are like middle distance athletes. They have incredible endurance. The forwards, not so much. They have more fast-twitch muscle fiber that doesn't need as much oxygen but tires really quickly. When they train them all the same, the forwards get injured like crazy. Those guys just cannot train as much without getting injured, because they can contract their muscles so explosively.
The Netherlands led the way in this. They have been screening for muscle fiber types and saying, "This guy's really good. Don't ruin him. Because the first thing you'll do if you over train him is start making those muscle fibers take on the characteristics of slower twitch, which you don't want, and then he'll get hurt." They've been great with sports science, and that's why a country with 16 million people has been second and third in the last two World Cups.
Mike Walsh: We're at this point now in genetics where we have the ability not just to identify but to edit genes. Given the discoveries around CRISPR/Cas 9 and genomic editing, do you think we're going to see a future where people are going to intervene early to create the kind of athletes they actually want?
David Epstein: In some ways, we don't know a lot of genes that go into being a perfect athlete. It would be hard to make someone perfect. In fact, if you do a calculation of the probability of all the genes known that contribute to sports performance, the probability of any one person having them all based on their frequency would be like winning the lottery 32 times in a row.
Mike Walsh: So we don't actually have a genetic blueprint for Usain Bolt?
David Epstein: Right. Most traits are the result of lots of genes with small effects, but there are now two known cases with regard to athleticism where a single gene has a huge effect. One is a gene called myostatin, which produces a protein that basically tells your muscles when to stop growing. In people who have a certain mutation, that muscle stop sign disappears. This will first manifest if they're a baby and they look like they've been lifting weights, basically.
The first study that was found on this was this German baby. If you go to the Journal of the American Medical Association, there's pictures of his butt and his thighs and stuff. That same mutation now been found in racing whippets, dogs that are bred for racing. People were just breeding them to be fast, and it turned out that they bred this mutation into them. If you Google "Belgian Blue cattle" you'll see these cows that look like they're the Incredible Hulk. Same mutation. The only adult now who has a documented version of this, was a professional sprinter who was that baby's mother. We know that has a big effect.
Mike Walsh: This is a known mutation?
David Epstein: A known single-gene mutation that has a huge effect on muscle and they have like no fat. There's another one. I write about this guy in the book, who actually recently passed away, named Eero Mäntyranta. He was a Finnish cross-country skier, seven-time Olympic medalist. When I went to visit him it was great for narrative because he's a reindeer farmer in the Arctic. It doesn't get much better than that. In cross-country skiing he won some events in margins that had never before been seen. Yet, there was a kind of a pall cast over his career, because he had so many red blood cells that it was assumed he was cheating.
Mike Walsh: They thought he was Lance Armstrong, basically.
David Epstein: Exactly, and he was, but he was Lance Armstrong, naturally. He was very similar, without doping. About 20 years after he retired, these Finnish researchers started studying his whole family and found that about 29 of the 90 people they studied had this mutation that caused them to over respond to their own body's natural EPO, producing a crap load of red blood cells. EPO was what Lance Armstrong was doping with. This guy had like 50 percent more red blood cells than I do.
Mike Walsh: He was naturally doping.
David Epstein:Naturally doped, exactly. His nephew who had it, also an Olympic gold medalist. His niece, a world junior champion. Nobody in the family who didn't have it was good at racing.
Mike Walsh: What about epigenetics? Do you think we can turn these genes off and on?
David Epstein: I think we can. Although, I think it won't be as easy as it's been made out to be in the press.
Mike Walsh: Will this be 21st century doping?
David Epstein: I think so, yeah. Some of the stuff that's been out in the press, the hype about epigenetics has been based on mice, and humans clear the epigenome a lot more thoroughly than mice do. That said, you can silence certain genes. Say if we can silence the myostatin gene, you can turn off that protein that tells muscles when to stop growing. Even aside from that, there's a version of gene therapy called naked DNA dump, which is basically like just dumping a bunch of genes made in a lab into the bloodstream and hoping some of them get picked up. A bright molecular bio grad student could pull that off and it would probably be effective. But it might also run out of control..
Mike Walsh: You might end up with cancer.
David Epstein: Yeah, but I think athletes have shown that they're willing to try stuff even if it's very, very harmful for their health. Anytime you have these single gene targets, that means those are targets for various kinds of gene editing or manipulation.
Mike Walsh: What about when you move beyond physiology into cognition? To what degree do you believe that intelligence is also susceptible to this nature versus nurture debate? People accept that we are born with different physical abilities, but it becomes very political and a question of ethics when people start talking about cognition.
David Epstein: Yeah. I've been learning about this recently. I can't say I'm thrilled with everything I've been discovering, but I have been convinced that the work is incredibly rigorous in some areas and that there is a significant nature component to a lot of cognitive abilities. That doesn't mean that people can't improve them, and that doesn't mean that people don't need the best opportunities. Again, I always think of when it comes to this nature versus nurture study that better than either viewing the world only as we would like it to be or being a pessimist and a total terminist is finding out the differences between people that are real, not the results of bias or folklore, which of those matter for the outcomes we care about, and then how can we work with those to get the optimal outcomes for all people.
There's a lot that intelligence research has to say about the fact that there are major genetic components to cognition. For example, in adoption studies, the cognitive ability tests of adopted kids look a lot like their biological parents and nothing like their adoptive parents. There were even some unethical studies done, where kids were essentially randomly assigned to families so that they could be studied to look at the impact. There's some impact, but the kids still tend to resemble their biological families.
Mike Walsh: Why do you think we have this natural bias that somehow cognitive ability isn't a result of evolution? You mentioned there was a great study where they asked people about the outcomes of evolutionary biology.
David Epstein: Yeah. There was a study that showed that people who are the most likely to ridicule others for not believing in evolution are also the most likely to deny the findings of evolutionary psychology and the reverse. People who outwardly say, "I don't believe in evolution," if they're then given some of the tenets of evolutionary psychology are more likely to accept them, which is like self-righteousness in both directions.
I think there are a number of reasons for this. In this country, it partly because certain kinds of cognitive ability testing have been used in such heinous and offensive ways to justify discrimination against certain types of people. Also, I think it goes against our feeling that we're totally in control of our fate. Most people don't think that everything about their life circumstance is exactly due to their own agency, but maybe that's not an idea they want to pass along to anyone. I think a major concern is that you'll deter people from trying harder or say that, "That's not fair, life isn't fair.” But life isn't fair.
Mike Walsh: It seems a logical outcome from what you're saying is - if we do physiological testing to see what people are predisposed to in terms of sports, why not do similar testing to work out what fields or professions people should join?
David Epstein: I agree. Although, again, it's not necessarily the world as I would like it to be. I'd love it if just hard work was the only thing to distinguish people, because then you'd know exactly what you have to do. Given the world as it is, I think we should help everyone find the way they can best exploit their talents. Which is why, as we were talking before, I got so interested in things like screening people for spatial perception. Because we know that ability is important for certain areas of science and engineering.
Mike Walsh: And for being a fighter pilot.
David Epstein: And for being a fighter pilot or a bobsled driver. We know it's not strongly inherited from parents. We know it's not well correlated with other aspects of cognitive ability. We know it's not correlated with socioeconomic status, and it doesn't get picked up in school. Here you have this goldmine, this thing where we know there are hidden gems out there in low socioeconomic status communities, and we're not doing anything to find them. Instead we're saying, "Everyone's got equal abilities." Let's go find these people and help them be successful.
Mike Walsh: Professional sports has found a way to naturally search the world for talent. In some ways the problem is not so much testing but the widespread availability of an organized form of rewards.
David Epstein: Yeah.
Mike Walsh: So, what are the Olympics for professions?
David Epstein: That's a great question. I was reading an article about Google. I guess it was the CFO or somebody like that saying, "We don't really care about your college test scores and stuff," and that got interpreted by some of the press as, "See, test scores are meaningless. That stuff doesn't matter. They're just interested in your creativity."
I read the guy's full remarks, and that's not what he was saying at all. What he was saying was, "I don't give a crap what you did in school. If I give you this hard problem on the spot and you can think about it creatively and work on it, great." That's about as rigorous a form of cognitive ability testing as you can get, being thrown in a room with a question you don't know about.
I think of that they do in the tech communities, where they just make you try the job right there. Or people can just create things on their own. Athletes can get scouted now through these combines or tryouts, or because you see them on TV or because someone has filmed them. Now people can go build something online and it's like, "This is me, the equivalent of being a college basketball player. Scout me from this thing I've made." Which I think is kind of great, because it's opened up
the audition to the whole world. I think it's also made it a lot more competitive, which is good or bad depending on where you're standing at the moment.
Mike Walsh: Fortunately, you seem to be genetically selected to finding great stories and talking about them. Thanks very much, David. It's been a pleasure talking to you.
David Epstein: It's been my pleasure. Thank you.
