Алекс Хатчинсон – Endure: Mind, Body and the Curiously Elastic Limits of Human Performance (страница 3)

Reaching the “limits of endurance” is a concept that seems yawningly obvious, until you actually try to explain it. Had you asked me in 1996 what was holding me back from sub-four, I would have mumbled something about maximal heart rate, lung capacity, slow-twitch muscle fibers, lactic acid accumulation, and various other buzzwords I’d picked up from the running magazines I devoured. On closer examination, though, none of those explanations hold up. You can hit the wall with a heart rate well below max, modest lactate levels, and muscles that still twitch on demand. To their frustration, physiologists have found that the will to endure can’t be reliably tied to any single physiological variable.

Part of the challenge is that endurance is a conceptual Swiss Army knife. It’s what you need to finish a marathon; it’s also what enables you to keep your sanity during a cross-country flight crammed into the economy cabin with a flock of angry toddlers. The use of the word endurance in the latter case may seem metaphorical, but the distinction between physical and psychological endurance is actually less clear-cut than it appears. Think of Ernest Shackleton’s ill-fated Antarctic expedition, and the crew’s two-year struggle for survival after their ship, the Endurance, was crushed in the ice in 1915. Was it the toddlers-on-a-plane type of endurance that enabled them to persevere, or straightforward physical fortitude? Can you have one without the other?

A suitably versatile definition that I like, borrowing from researcher Samuele Marcora, is that endurance is “the struggle to continue against a mounting desire to stop.” That’s actually Marcora’s description of “effort” rather than endurance (a distinction we’ll explore further in Chapter 4), but it captures both the physical and mental aspects of endurance. What’s crucial is the need to override what your instincts are telling you to do (slow down, back off, give up), and the sense of elapsed time. Taking a punch without flinching requires self-control, but endurance implies something more sustained: holding your finger in the flame long enough to feel the heat; filling the unforgiving minute with sixty seconds’ worth of distance run.

The time that elapses can be seconds, or it can be years. During the 2015 National Basketball Association playoffs, LeBron James’s biggest foe was—with all due respect to Golden State defender Andre Iguodala—fatigue. He’d played 17,860 minutes in the preceding five seasons, more than 2,000 minutes ahead of anyone else in the league. In the semis, he surprisingly asked to be pulled from a game during a tense overtime period, changed his mind, drained a three-pointer followed by a running jumper with 12.8 seconds left to seal the victory, then collapsed to the floor in a widely meme-ified swoon after the buzzer. By Game 4 of the finals, he could barely move: “I gassed out,” he admitted after being held scoreless in the final quarter. It’s not that he was acutely out of breath; it was the steady drip of fatigue accumulating over days, weeks, and months that just as surely pushed James to the limits of his endurance.

At the opposite end of the spectrum, even the greatest sprinters in the world fight against what John Smith, the coach of former 100-meter world-record holder Maurice Greene, euphemistically calls the “Negative Acceleration Phase.” The race may be over in ten seconds, but most sprinters hit their top speed after 50 to 60 meters, sustain it briefly, then start to fade. Usain Bolt’s ability to stride magisterially away from his competitors at the end of a race? A testament to his endurance: he’s slowing down a little less (or a little later) than everyone else. In Bolt’s 9.58-second world-record race at the 2009 World Championships in Berlin, his last 20 meters was five hundredths of a second slower than the previous 20 meters, but he still extended his lead over the rest of the field.

At the same world championships, Bolt went on to set the 200-meter world record with a time of 19.19 seconds. A crucial detail: he ran the first half of the race in 9.92 seconds—an amazing time, considering the 200 starts on a curve, but still slower than his 100-meter record. It’s barely perceptible, but he was pacing himself, deliberately spreading his energy out to maximize his performance over the whole distance. This is why the psychology and physiology of endurance are inextricably linked: any task lasting longer than a dozen or so seconds requires decisions, whether conscious or unconscious, on how hard to push and when. Even in repeated all-out weightlifting efforts—brief five-second pulls that you’d think would be a pure measure of muscular force—studies have found that we can’t avoid pacing ourselves: your “maximum” force depends on how many reps you think you have left.

This inescapable importance of pacing is why endurance athletes are obsessed with their splits. As John L. Parker Jr. wrote in his cult running classic, Once a Runner, “A runner is a miser, spending the pennies of his energy with great stinginess, constantly wanting to know how much he has spent and how much longer he will be expected to pay. He wants to be broke at precisely the moment he no longer needs his coin.” In my race in Sherbrooke, I knew I needed to run each 200-meter lap in just under 32 seconds in order to break four minutes, and I had spent countless training hours learning the feel of this exact pace. So it was a shock, an eye-widening physical jolt to my system, to hear the timekeeper call out, as I completed my first circuit of the track, “Twenty-seven!”

The science of how we pace ourselves turns out to be surprisingly complex (as we’ll see in later chapters). You judge what’s sustainable based not only on how you feel, but on how that feeling compares to how you expected to feel at that point in the race. As I started my second lap, I had to reconcile two conflicting inputs: the intellectual knowledge that I had set off at a recklessly fast pace, and the subjective sense that I felt surprisingly, exhilaratingly good. I fought off the panicked urge to slow down, and came through the second lap in 57 seconds—and still felt good. Now I knew for sure that something special was happening.

As the race proceeded, I stopped paying attention to the split times. They were so far ahead of the 4:00 schedule I’d memorized that they no longer conveyed any useful information. I simply ran, hoping to reach the finish before the gravitational pull of reality reasserted its grip on my legs. I crossed the line in 3 minutes, 52.7 seconds, a personal best by a full nine seconds. In that one race, I’d improved more than my cumulative improvement since my first season of running, five years earlier. Poring through my training logs—as I did that night, and have many times since—revealed no hint of the breakthrough to come. My workouts suggested, at most, incremental gains compared to previous years.

After the race, I debriefed with a teammate who had timed my lap splits for me. His watch told a very different story of the race. My first lap had taken 30 seconds, not 27; my second lap was 60, not 57. Perhaps the lap counter calling the splits at the finish had started his watch three seconds late; or perhaps his effort to translate on the fly from French to English for my benefit had resulted in a delay of a few seconds. Either way, he’d misled me into believing that I was running faster than I really was, while feeling unaccountably good. As a result, I’d unshackled myself from my pre-race expectations and run a race nobody could have predicted.

After Roger Bannister came the deluge—at least, that’s how the story is often told. Typical of the genre is The Winning Mind Set, a 2006 self-help book by Jim Brault and Kevin Seaman, which uses Bannister’s four-minute mile as a parable about the importance of self-belief. “[W]ithin one year, 37 others did the same thing,” they write. “In the year after that, over 300 runners ran a mile in less than four minutes.” Similar larger-than-life (that is, utterly fictitious) claims are a staple in motivational seminars and across the Web: once Bannister showed the way, others suddenly brushed away their mental barriers and unlocked their true potential.

As interest in the prospects of a sub-two-hour marathon heats up, this narrative crops up frequently as evidence that the new challenge, too, is primarily psychological. Skeptics, meanwhile, assert that belief has nothing to do with it—that humans, in their current form, are simply incapable of running that fast for that long. The debate, like its predecessor six decades ago, offers a compelling real-world test bed for exploring the various theories about endurance and human limits that scientists are currently investigating. But to draw any meaningful conclusions, it’s important to get the facts right. For one thing, Landy was the only other person to join the sub-four club within a year of Bannister’s run, and just four others followed the next year. It wasn’t until 1979, more than twenty years later, that Spanish star José Luis González became the three hundredth man to break the barrier.