And sorry—who was Phil Maffetone again? A ponytailed back-cracker from suburban New York. Those were Stu’s two options: the man who wrote The Book versus the man who probably hadn’t read it. Ordinarily it would be an easy decision, but pain relief is the ultimate persuader. Stu decided to give the Maffetone Method a chance.
Okay, he told Phil. How do we start?
Simple, Phil began. To use fat as fuel, you need to do only two things: cut out sugar and lower your heart rate. “We store only a very limited amount of carbohydrate in our bodies,” Phil explained. “Compare this with a relatively unlimited supply of fat.” Carbs are a puddle; fat is the Pacific. At any time, your body has some 160,000 calories on tap: about 2,000 from sugar, 25,000 from protein, and nearly 140,000—87 percent—are fat. “Even an athlete with only 6 percent body fat will have enough fat to fuel exercise lasting for many hours,” Phil explained. “When you use more fat, you generate more energy and your carbohydrate supply lasts longer. When you teach your body to rely on fat, your combustion of carbs goes down, and so does your craving for them.”
But there’s no pussyfooting around. Your body loves fat; it’s a treasure your system would rather hoard than burn, so if it senses there’s any other fuel at hand, it will use that first and convert the leftovers into more fat. To free himself from the sugar-burn cycle, Stu would have to go cold turkey: he could stuff himself silly all day, but only on meat, fish, eggs, avocados, vegetables, and nuts. No beans, no fruit, no grains. No soy, no wine, no beer. Whole dairy like sour cream and real cheese were in; low-fat milk was out.
That was Part 1. Part 2 was even more basic: Slow down. When you sprint, Phil explained, you jack up your heart rate. Your body interprets a hammering heart as EMERGENCY! so it goes looking for those gas-soaked rags. It wants the fastest-burning fuel it can find, and that means sugar. But once you’ve conditioned your body to rely on fat, you’ll be able to run as fast as ever—and much faster. For Stu to keep his heart rate in his fat-burning zone, Phil had an easy formula: just subtract your age from 180. Stu was thirty-two years old, so Phil gave him a heart-rate monitor and set it for 153 beats per minute (148 plus five bonus beats because Stu was a highly conditioned athlete). Anytime the monitor beeped, it meant Stu had to slow to a walk until his pulse eased back down.
For three weeks, Stu was a perfect disciple. Come the six-day race in France, however, he’d had enough. It was humiliating enough when all the other runners shot off around the track while he trailed them at a walk (“Yech!” Stu grimaced), but to watch them snacking on cookies and candy at the aid stations while he had nothing but almonds … well, that just bordered on human-rights abuse. Unfortunately, Phil Maffetone had come to France with him, so Stu had to sneak cookies off the aid station table and hide them at the far end of the track, where he could munch later when Phil wasn’t looking.
But before digging into his stash, Stu noticed something. For once, he could actually see what was going on. Usually during a race he was huffing along with his chin on his chest, but this time he was head high and breathing easy. Come to think of it, he’d felt that way during every run for the past three weeks. For most runners, enjoying the view is a rare sensation; as soon as fatigue kicks in, your eyes drop to the pavement and your vision tunnels. You’re no longer in the present; you’re locked on to how far you’ve come and how far you’ve got to go. Stu always assumed pain was the price of gain, but since he’d been on the Maffetone Method, his runs had actually been a pleasure.
“Each energy-producing state has specific and real sensory-based references,” he’d learned. “Your body knows this by the way the world ‘looks,’ ‘sounds,’ and ‘feels.’ When you move in a comfortable fat-burning state, the visual information is distinct, expansive, and three dimensional with a peripheral vastness and expansiveness that is unique and identifiable. It’s as though you are in a 3-D surround vision movie theatre.”
You’re seeing with the eyes of a hunter. But when your heart rate climbs, you become the hunted. “As soon as you shift into a more challenging sugar-burning state, visual information tends to collapse inward, the peripheral fringes tend to disappear and your attention gets drawn into a much narrower field of vision. Visual images tend to flatten out, become two-dimensional, and you begin to feel as though you are running through a tunnel with the world painted on the inside walls.”
So that’s how hunter-gatherers run antelopes to death. They don’t act like the animal they’re trying to kill; instead they’re silent and graceful, moving easily with their eyesight sharp, their breathing controlled, their bottomless body-fat energy on tap. Much the way Stu was moving now, in fact, as he smoothly and stealthily pursued the runners who’d dropped him at the start. Three weeks earlier, Stu had been so hobbled by injury he couldn’t compete; now, he was chasing down the best ultradistance runners in the world and getting faster by the day. Stu felt so good that for the entire six days, he never dug into his cookie stash. He set a new American record of 571 miles, crushing the old one by more than a half-marathon and finishing in second behind only the Beast himself, 24-Hour World Record holder Jean-Gilles Boussiquet of France.
That did it; Stu was now a fat-as-fuel true believer. For the next ten years he whirlwinded through the record books with such strength and style, it looked more like art than effort. In a display of “virtually flawless footracing,” as one journalist put it, Stu defeated the reigning world champion in a thousand-mile showdown and not only shattered the old mark by sixteen hours, but even ran his second five hundred miles faster than his first. He handled the back half of his life the same way; instead of slowing down in his forties, he got stronger, running more than fifty miles a day as he set a new speed record from Los Angeles to New York City. “No other American ultrarunner, male or female, has exhibited national class excellence at such a wide range of racing distances,” his American Ultrarunning Hall of Fame induction proclaimed.
But the funny thing is, Stu wasn’t even Phil’s best student. Compared with Mark Allen, Stu was … well, there’s really no comparing anyone to Mark Allen. When Mark came to Phil in the late eighties, he was in his twenties but already feeling old. Triathlons were beating him up and not paying off; Mark was always hurt in training and blowing up in races, either fading toward the finish or dropping out altogether. Like Stu, his broken body gave him an open mind. “I was warned that his methods were probably going to sound crazy,” Mark would recall. Not to mention embarrassing: Phil made Mark pedal far behind the pack during group rides and plod along at half speed during runs. Mark’s training partners were convinced he was washed up … until four months later, when Mark went flying past. “I had become an aerobic machine!”
“I was now able to burn fat for fuel efficiently enough to hold a pace that a year before was red-lining my effort,” Mark explained. “I was no longer feeling like I was ready for an injury the next run I went on, and I was feeling fresh after my workouts instead of being totally wasted.” Mark soon tore off an insane streak: for two years, he didn’t lose a race anywhere, at any distance. He won Ironman six times, including a stunning comeback victory at age thirty-seven, but what’s more intriguing is what happened after he retired. Bikes got lighter, wetsuits got sleeker, training and nutrition became more lab-tested and sophisticated—yet no one could touch Mark’s times. It was nearly two decades before another Ironman could match him.