Iron War
Page 18
Instead of arising from sensory feedback from the body to the brain, Sam argues, perception of effort arises from the brain’s own activity level in two key areas. The first area is the motor cortex, whose job is to generate the electrical signals that make the muscles contract. The motor cortex is connected to the muscles through nerves that snake through the spinal cord. It also has direct links to the brain’s sensory cortex, where conscious perceptions are produced. Because of these dual links, the more active the motor cortex becomes, the harder the muscles work and the more effort is consciously perceived.
The second area of the brain involved in perception of effort is the anterior cingulate cortex (ACC), a collar-shaped area deep inside the forebrain whose function during exercise is more complex and nuanced. Brain imaging studies have shown that the ACC becomes intensely active when a person is performing mental tasks that require sustained attention and involve conflict resolution and response inhibition. The classic example is the Stroop Test. In this test a person is presented with a series of words, all of which are names of colors. The words are also presented in a variety of colors. The Stroop Test subject is required to simply (but quickly) name the color in which the word is printed. This is very easy to do when the meaning of the word and the color of the text match but surprisingly difficult when they diverge. There is a reflexive impulse to just read whatever word one is looking at, which the test taker must inhibit while making a conscious effort to speak the name of the color in which the word is presented. To perform well in a Stroop Test, one must sustain focused attention, resist impulses, and resolve cognitive conflicts. This combination of tasks is the specialty of the ACC, so this part of the brain becomes intensely active during a Stroop Test.
The ACC also becomes highly active during physical exercise. One reason it does so is that it has a role in regulating heart rate, breathing, and other autonomic responses to exercise. Another reason, Samuele Marcora believes, is that exercise is “cognitively demanding” in a way that is very similar to the Stroop Test. Exercise, by activating the motor cortex, generates a perception of effort that is unpleasant. This discomfort, in turn, gives rise to an impulse to stop. To keep going the exerciser must continuously resist this impulse and resolve the conflict between the desire to quit and the desire to continue in favor of the latter. Ironically, this cognitive challenge itself adds to the perception of effort by activating the ACC, which, like the motor cortex, has direct links to the sensory cortex, where conscious perceptions are produced.
So perception of effort during exercise has two components. The first is the feeling produced by activity in the brain’s motor cortex, which drives the muscles directly. The second is the feeling produced by the cognitive effort (centered in the ACC) required to resist the impulse to quit exercising.
Exercise is generally not recognized as a cognitively demanding activity. Samuele Marcora argues that not only is exercise cognitively demanding but its cognitively demanding nature is one of the main reasons exercise feels hard and ends in exhaustion.
In 2008 Sam conducted an ingenious study proving that exercise is, in fact, cognitively demanding. He began with the premise that if endurance exercise is truly cognitively demanding, then athletes should give up more quickly in exercise tests that they start in a mentally fatigued state than they do in exercise tests that they start when mentally fresh. Sam recruited sixteen subjects and asked them to pedal stationary bikes to exhaustion at a fixed high intensity on two occasions: once after performing cognitively demanding mental tasks, similar to a Stroop Test, on a computer for ninety minutes to induce mental fatigue (and, in particular, fatigue in the ACC) and once after watching “emotionally neutral” documentaries for ninety minutes as a nonfatiguing control scenario. Incredibly, the mental task reduced performance in the subsequent ride to exhaustion by 15 percent compared to the control condition. On average, the subjects lasted for twelve minutes, thirty-three seconds on the bike after watching documentaries. After playing the brain-draining video games, they gave up after only ten minutes, thirty-nine seconds.
Physical fatigue was obviously not a factor. The mental task imposed only brain-centered fatigue, especially in the ACC. The study thus proved that exercise is cognitively demanding, for if it were not, preexisting mental fatigue would not have affected physical performance. The study also proved that the effect of mental fatigue on exercise performance is mediated by perception of effort. The subjects quit at the same maximal level of perceived effort in both exercise trials, but they started the post-videogame trial at a higher level of perceived effort, which was why they did not last as long.
Of the two sources of perceived effort in exercise—activity in the motor cortex, which drives the muscles directly, and activity in the ACC, which resists the impulse to quit—the motor cortex is most influential in shorter, higher-intensity exercise bouts, and the ACC is most influential in longer efforts. The reason may be that, whereas perception of effort is linked equally to the intensity and duration of activity in the motor cortex, it is linked mainly to the duration of activity in the ACC. A short race lasting, say, ten minutes will certainly leave an athlete feeling exhausted, but that feeling will arise mostly from the intense activity in the motor cortex that is required to drive the legs as hard as they can be driven for a mere ten minutes. The cognitive challenge of sustaining mental focus (that is, resisting the desire to quit) through a ten-minute race is comparatively smaller. When the duration of a race extends beyond minutes to hours, however, perception of effort comes increasingly from the strain of sustaining mental focus on the task.
This difference explains why most experienced triathletes feel that Ironman racing is more psychologically challenging than competing in shorter races. In 2002 Dave and Mark were asked if they would like to see an Ironman triathlon included in the Olympic Games alongside the shorter triathlon that was already an Olympic event. Both men said they would—and for the same reason.
“The shorter races are a little more physical,” Mark said. “Once you get into the longer races, it becomes more a test of you as a person on top of a test of you as an athlete.”
“I agree with Mark,” Dave said. “A race that comes down to a 10K run is quite different from the mental game that goes on in an Ironman.”
Ironman racing is extremely physical, of course. It pays to have the greatest physical capacity you can possibly achieve. But the reason it pays is that the greater your physical capacity is, the farther and faster you can go before you reach the maximum level of suffering you can tolerate. No matter how great your physical capacity, it is this tolerance that ultimately determines your performance limits. Given two athletes of equal physical fitness, the one who tolerates the most suffering will prevail. And at the Ironman distance small differences in suffering tolerance are magnified.
THE TYPICAL ENDURANCE ATHLETE thinks of training strictly as a process of strengthening the body so that it can go faster and farther before it runs out of gas. And that’s certainly how most exercise scientists think of training.
Not Dave Scott and Mark Allen. The two guys who were able to go faster and farther than anyone else thought of training primarily as a process of cultivating a greater tolerance for the suffering of extreme fatigue. They pursued this objective in a commonsense way: by repeatedly exposing themselves to extremely high levels of fatigue-related suffering in workouts. Intuition told them that, as friction builds calluses that protect the skin against friction, so suffering in exercise must develop mental strength that increases the mind’s tolerance for suffering in exercise. So Dave and Mark both consciously sought out misery in workouts the way other athletes seek to cover a certain number of miles at a particular pace.
“You’re out there in a race, and it hurts—it’s uncomfortable,” Mark once explained. “You say to yourself, ‘Hey, what am I doing? I don’t want to go this hard or be in this much pain or be this hot.’ But if you have trained so that you have experienced these feelings before, then it
isn’t so foreign—you’ll be able to work through it.”
Dave too approached workouts as opportunities to practice suffering. He thought about this practice differently, though—as another dimension of the game-playing that always structured his exercise experience.
“In workouts, when I’m by myself riding for four hours, I play mental games,” Dave told Bob Babbitt in 1996. “I go through periods where I feel like I’m going to collapse, and I pull myself out of it. When I put that into a race, it seems to pay off.”
Dave did not distinguish races from workouts to the same degree that most triathletes do. In races and workouts alike, his intention was “to see what he could do”—to test, define, and redefine his limits. Dave understood that his ability to manage and tolerate suffering, or perceived effort, was always the primary barrier to extending his capacities. The games he played were ways of motivating himself to absorb more suffering and thereby go faster or farther than he would be able to go otherwise.
One of Dave’s favorite swim workouts was a set of seven 500-yard intervals with a short rest period after each. As he worked his way through the set, Dave swam faster and faster. But he also made the rest periods shorter and shorter. Plenty of other swimmers would do one or the other—either increase the tempo of the intervals or reduce the rest periods between them. Dave did both. He thought it was a good idea to practically cripple himself with fatigue before attempting his fastest efforts.
A reporter watched Dave perform this workout at the Civic Center Pool in Davis on a winter night in 1983. Earlier that same day the reporter had driven a car alongside Dave as he completed a long ride in frigid temperatures and howling winds.
“I feel terrible,” Dave told the reporter as he pedaled up a tough one-and-a-half-mile climb known locally as Cardiac Hill. He was smiling as he spoke these words.
Dave took a special satisfaction in trying hardest when he felt most unable. He relished and even looked forward to those days in training when his body felt defeated. Instead of taking it easy on those days, he would seize them as opportunities to go even harder.
“I can go to workouts totally haggard and whipped and feeling like I’ve got an anvil on my back, and I can still press the ‘will it’ button,” he once said. “I have the capacity to persevere, and I like doing it—I love doing it. It doesn’t matter when it is. I don’t have to pick the perfect scenario. ‘Okay, I’m going to go really hard today because I feel really rested and ready. I had my guava juice and I feel great.’ I just wake up and say, ‘Okay, I can do it.’ So I do it.”
Mark’s style of suffering was starkly different. Instead of piling on work and never giving himself a break, he picked his spots. He suffered just as intensely as Dave in workouts, but not as often. If Dave differed from other elite triathletes in pushing hardest when he was weakest, Mark differed from his peers in precisely the opposite way, through his habit of storing strength and waiting patiently until he was absolutely ready to challenge his limits.
“Mark has the ability to contain and absorb energy, to use it when he needs it,” Mike Rubano, Mark’s massage therapist, told Outside. “To hold it, hold it, hold it, and then explode.”
Each year, between January 1, when he resumed training after a post-Ironman break, and April 1, Mark never allowed his heart rate to exceed the Phil Maffetone–imposed limit of 155 beats per minute. This was a period of absorbing energy for later use. There were temptations to stray from this wise and patient approach, but Mark was wise and patient enough not to give in to them.
“You come back a little out of shape, you start working out, you get an ache and a pain here or there, and you see people who have been working out straight through, and you think, Man, I shouldn’t have taken time off,” Mark said in a 1985 interview. “But that doesn’t last long. After about a month you can feel the energy coming back into your body—there’s a transition from someone who’s just working out to someone who’s feeling really strong.”
Come April, Mark finally added high-intensity efforts to his training mix. By this time his body contained so much stored potential that he positively exploded into these hard sessions, which in turn catapulted his fitness to a whole new level. The training partners who were leaving Mark behind in January were now left far behind him.
Athletes who got their first exposure to Mark in the winter faced a rude awakening in the spring. One such athlete was Jürgen Zäck, a German triathlete several years younger than Mark with exceptional cycling ability. One January Mark and Jürgen climbed to the top of Palomar Mountain—the toughest climb in San Diego County—on their bikes. Jürgen dropped his famous and accomplished new training partner easily. When Mark finally reached the summit, ten minutes behind, he found the German riding in circles, waiting, gloating.
A few weeks later they repeated the workout, and again Jürgen was turning circles at the top when Mark got there. But this time Mark was only five minutes behind. A few more weeks went by, and they did it again. Mark finished right behind Jürgen, who had no chance to turn circles on this occasion. On their fourth trip up Palomar Mountain, Mark dropped Jürgen. When he reached the top, five minutes behind, Jürgen found Mark turning circles, waiting, gloating.
DAVE SCOTT AND MARK ALLEN were not the only triathletes of their generation who suffered like sled dogs in training. Scott Molina, Scott Tinley, and Mike Pigg, among others, also punished themselves famously. Yet Tinley and Pigg were among the group of also-rans who found themselves struggling more than three miles behind Dave and Mark on the Queen K in the final stretch of the 1989 Ironman, and Molina would have been among them too if he’d done the race. It would seem, then, that other factors besides repeated suffering in training contribute to the magnitude of an elite triathlete’s capacity to tolerate suffering in races.
One look at Dave Scott tells you this mental capacity must be at least partly hardwired—genetic. Dave was always the last to quit in any contest he cared about from his earliest years.
“I hadn’t been born with the natural ability to swim, but I wanted to be the best at it, anyway, so I swam until it hurt, then went back for more,” Dave wrote of his first days in the pool as a young boy.
Some people are born with big feet. Others are born with exceptionally good eyesight. Perhaps Dave was born with a crazily overdeveloped ACC—a hidden suborgan of extraordinary capacity to tolerate suffering lurking deep inside his forebrain.
Before Dave was even 10 years old his father wrote checks for the household bills once a month, stuffed them into envelopes, and sent his son out to deliver them directly to their addressees by bicycle to save postage. Dave, of course, made a game of it, seeking to complete his rounds faster each month. Verne had meant to build discipline in his young son by forcing him to perform a productive task he did not enjoy. But Dave loved it.
By age 13 Dave was racing the bus more than five miles to school on his bike. He did not learn such behavior from anyone; it came naturally from within. Whenever Dave spoke of this capacity, he seemed amazed by it himself and acknowledged that it was not something he controlled. It was just there.
“I’ve always felt that, as the race lingers on, the psychological part of it becomes a huge factor,” he said in a Competitor interview. “I seem to thrive on that, even though I’m feeling fatigued just as everyone else is.”
Dave not only thrived on the challenge of feeling fatigued in races but was compelled to confront that challenge in every single workout. Some mysterious inner force coerced him to go hard every day without respite. The price of a few missed workouts was essentially the world’s worst case of cabin fever—a miserable sense of confinement. Complicating matters, this mysterious inner force nourished Dave’s sense of self, cultivated an image of himself as the last man to quit. So it wasn’t just fear of cabin fever but also fear of failing to live up to his own perfect standard that drove Dave, and ironically drove him so hard that he sometimes broke down and suffered the torture of an unsatisfied need to move.
/> In Mark Allen, it’s apparent that the will to resist the impulse to quit must be at least partly nurtured—that the ACC you’re born with is not necessarily the ACC you die with. As a young swimmer, Mark did not have much mental stamina. As a mature triathlete, he did. Mark might not have developed this capacity if the wounds he carried away from his boyhood had not ultimately affected him in accordance with the principle that whatever does not kill us makes us stronger.
Behind how many great male athletes is a lousy father? Mark Allen. Lance Armstrong. Haile Gebrselassie. Michael Phelps. History’s greatest triathlete, cyclist, runner, and swimmer all had difficult relationships with their dads in one way or another. Coincidence? Not bloody likely.
Mark Allen sometimes speaks to this point—in general terms, scrupulously avoiding self-references—in interviews.
“If you dig deep enough into the life of any of the top athletes who are pushing their bodies to the absolute limits, you’re going to find a story,” he once said. “You’re going to find something that those athletes are trying to make up for that they didn’t get when they were younger. Something that hurt them.”
This is a purely motivational explanation, and undoubtedly a valid one. But Samuele Marcora believes that the brains of such athletes are also physically transformed by their early experiences. He believes that living in a difficult family environment may in fact strengthen the ACC in its own way.
“There is now some evidence that chronic exposure to situations requiring self-regulation (in other words, the exertion of effort to control your own behavior) improves self-regulation in completely different situations,” he wrote in an e-mail message. “Chronic exertion of cognitive effort required to control your own emotions and deal with difficult family situations may induce neurocognitive adaptations that will translate into a competitive advantage during endurance competitions later on in life. I don’t have experimental data to back this up. But, according to my endurance performance model based on current psychobiological research, this transfer is certainly plausible.”