Endure. Alex Hutchinson

in North Toronto. As I recall, I finished last—or maybe second last, since one of his running crew very sweetly condescended to run at my pace. Alex disappeared from sight after the first bend. As you will discover, as you continue in these pages, Alex writes about the mysteries of endurance as a student of the science, a sports fan, and a keen observer of human performance—but also as a participant. He has his own anomalous races to explain.

      It must be stressed, though, that this is not a running book. There are plenty of running books out there, and as a runner I have read many of them. But they are insider’s accounts written for other insiders: whether or not a runner should fore-foot or heel-strike, or aim for a cadence of 180 strides per minute, is a question only of significance to runners whose self-involvement extends all the way to the soles of their feet. But one of the (many) pleasures of Endure is how convincingly Hutchinson broadens the stakes. In one of my favorite passages, from the chapter on pain, Hutchinson writes of the attempt by Jens Voigt to break cycling’s “one-hour” record. Voigt was famously indifferent to pain. But when he climbed off his bike, after breaking the record, Hutchinson tells us he was in agony: “the pain he’d been pushing to the margins of his consciousness came crashing down.” That is a cycling story. But in Hutchinson’s hands it also becomes a way of asking a much deeper and more consequential question about how our physiology interacts with our psychology. In a wide variety of human activity, achievement is not possible without discomfort. So what is our relationship to that pain? How do the signals of protest from our brain interact with the physical will to keep moving? You don’t have to be a maniacal cyclist to appreciate that discussion. If anything, that discussion is likely to dissuade you from ever becoming a maniacal cyclist. “Everything was aching,” Voigt said. “My neck ached from holding my head low in that aerodynamic position. My elbows hurt from holding my upper body in that position. My lungs hurt after burning and screaming for oxygen for so long. My heart hurt from the constant pounding. My back was on fire, and then there was my butt! I was really and truly in a world of pain.” Oh man. It was painful just to read that passage.

      Does Endure solve the puzzle of the anomalous race? In one sense, yes. My problem, I now realize, is that I tried to make sense of those performances using an absurdly simple model of endurance. The time I ran was my output. And so I worked backward and tried to identify the corresponding inputs that must have made it possible. Did I take one day of rest beforehand, or two? How quick was that hill workout the week before? Is there something to be learned from the last set of intervals I did? The data that we gather from our GPS sports watches makes this kind of thinking even more seductive: it encourages us to paint a simple picture of how and why our body moves through the world. After you’ve read Endure, I promise you, you’ll never settle for the simple picture again. There are many things Garmin cannot tell you. And luckily, for those many things, we have Alex Hutchinson.

Two Hours

       May 6, 2017

      The broadcast booth at the Autodromo Nazionale Monza, a historic Formula One racetrack nestled in the woodlands of a former royal park northeast of Milan, Italy, is a small concrete island suspended in the air over the roadway. From this rarefied vantage point, I’m trying to offer thoughtful guest commentary to a live-streaming audience of an estimated 13 million people around the world, many of whom have rousted themselves out of bed in the middle of the night to watch. But I’m getting antsy.

      The race beneath me is hurtling toward a conclusion that almost no one, through months of speculation and spirited debate, had considered possible. Eliud Kipchoge, the reigning Olympic marathon champion, has been circling the racetrack for an hour and forty minutes behind an exquisitely choreographed formation of runners blocking the wind for him—and, remarkably, he’s still on pace to run under two hours for 26.2 miles. Given that the world marathon record is 2:02:57, and given that records are usually shaved down in hard-fought seconds, Kipchoge’s performance is already straining the limits of my ability to convey surprise and awe. Giant screens in front of me are flashing detailed statistics about Kipchoge’s run, but my mind is drifting away from punditry. I want to slip out of the booth and get back down to the side of the track—to feel the crackling tension in the assembled crowd, to hear the rasp of Kipchoge’s breath as he runs past, and to look into his eyes as he pushes deeper into the unknown.

      In 1991, Michael Joyner, an ex-collegiate runner from the University of Arizona who was completing a medical residency at the Mayo Clinic in Minnesota, proposed a provocative thought experiment. The limits of endurance running, according to physiologists, could be quantified with three parameters: aerobic capacity, also known as VO₂max, which is analogous to the size of a car’s engine; running economy, which is an efficiency measure like gas mileage; and lactate threshold, which dictates how much of your engine’s power you can sustain for long periods of time. Researchers had measured these quantities in many elite runners, who tended to have very good values in all three parameters and exceptional values in one or two. What would happen, Joyner wondered, if a single runner happened to have exceptional—but humanly possible—values in all three parameters? His calculations suggested that this runner would be able to complete a marathon in 1:57:58.

      The reactions to his paper, which was published in the Journal of Applied Physiology, were mostly quizzical. “A lot of people scratched their heads,” Joyner recalls. The world record at the time, after all, was 2:06:50, which the Ethiopian runner Belayneh Densimo had run in 1988. A sub-two-hour marathon was not on anyone’s radar—in fact, when Joyner first presented his ideas in the mid-1980s, the idea was considered so preposterous that his paper was initially rejected for publication. But the seemingly outrageous time was not a prediction, Joyner emphasized—it was a challenge to his fellow scientists. In some ways, his calculation was the apotheosis of a century’s worth of attempts to quantify the outer limits of human endurance. This is how fast a human can run, the equations said. So what explained the chasm between theory and reality? Was it simply a question of waiting for the perfect runner to be born or the perfect race to be run—or was something missing from our understanding of endurance?

      Time passed. In 1999, the Moroccan runner Khalid Khannouchi became the first person to dip below 2:06. Four years later, Paul Tergat of Kenya breached 2:05; five years after that Haile Gebrselassie of Ethiopia broke 2:04. By 2011, when Joyner and two colleagues published an updated paper in the Journal of Applied Physiology titled “The Two-Hour Marathon: Who and When?” the idea no longer seemed ridiculous. In fact, the journal published an unprecedented thirty-eight responses from other researchers, speculating on the various factors that might bring the barrier closer. In late 2014, shortly after Dennis Kimetto of Kenya posted the first sub-2:03, a consortium led by a British sports scientist named Yannis Pitsiladis announced plans to break the two-hour barrier within five years.

      Still, two minutes and fifty-seven seconds remained a substantial gap. Also in 2014, Runner’s World magazine asked me to undertake a comprehensive analysis of the physiological, psychological, and environmental factors that would need to come together for someone to run a two-hour marathon. After reviewing mountains of data and consulting experts around the world, including Joyner, I presented ten pages of charts, graphs, maps, and arguments, concluding with my own prediction: the barrier would fall, I wrote, in 2075.

      That prediction leapt immediately to mind in October 2016, when I got an unexpected call from David Willey, then the editor in chief of Runner’s World. Nike, the biggest sports brand in the world, was preparing to unveil a “top-secret” project that aimed to deliver a sub-two marathon in just six months. We were being offered the opportunity to go behind the scenes to cover the initiative, which they’d dubbed Breaking2. I didn’t know whether to laugh or roll my eyes, but I couldn’t say no. I agreed to fly to Nike’s headquarters, in the Portland, Oregon, suburb of Beaverton, a few weeks later to hear their pitch. If someone had to debunk an overhyped marketing exercise, I figured the research for my earlier Runner’s World piece had left me as well equipped as anyone.

      As my guest spot on the television broadcast