CHAPTER EIGHT
The Science of Endurance
“For the majority of human existence, exercise was the norm or the baseline and being sedentary was the exception.”
—Shawn Bearden
“We’re all movers—and the movement is more important than the mechanics.”
—JPD
When I was a small child, I loved nothing more than visiting my grandmother, who was a retired children’s librarian. I would curl up next to her on her green velvet couch that smelled of floral potpourri and she would read Greek myths and Aesop’s fables with accents and intonations that brought the stories to life in her living room.
My favorite tale was that of the tortoise and the hare. My grandmother’s reading skills made the legendary duel sound as exciting as a live radio broadcast of game seven in the World Series. I was on the edge of my seat willing the turtle to touch the finisher’s tape first. And when that happened, I launched off the couch and jumped up and down cheering. (I was very young and it was hard to sit still. Nonetheless, the librarian in my grandmother did not appreciate the loud response.)
Now when I read the same timeless classic to my daughter, I try to bring in the level of suspense that my grandmother captured, but because of my experience with trail records I am also inclined to take long pauses as I try to dissect the strategy of each animal. I wonder what Aesop was really trying to tell us with this fable.
Did the rabbit lose because his heart rate was too high or because running and hopping took a greater toll on his body than walking?
Was the turtle’s diet better? Was it possible to stay cooler and better hydrated with a shell?
Why did the hare need a nap? Was he just lazy or sleep deprived?
Did the turtle win with persistence or was there an underlying physiological edge that has been overlooked.
When I close the book, my daughter does not jump up and yell. Instead, she looks at me and asks, “Now can we read the book that I want?” (She’s started to pick up on my attempt to indoctrinate her with endurance reads.)
The story of the tortoise and the hare has always resonated with me. One of my goals in life is to not try to outmuscle or outpace those around me, but to keep my head down and focus on what I’m doing so that I can do it well. In school, sports, and my work I have a history of being boringly good. It’s not sexy, but it’s effective.
On the record, I believed that consistent output over a prolonged period would be more efficient than short bursts of speed followed by lengthier rests. In other words, I wanted to hike, not run. I rationalized that walking would mean less impact on my joints, a reduced risk of falling, and decreased recovery time; it just seemed like a more natural way to cover more than two thousand miles.
Most folks would concede that walking quickly might allow one to outpace a severely fatigued runner or be more effective on a steep uphill, but logically it still makes sense that a runner would reach the finish line before a hiker, right?!
I ran my first road race when I was fourteen. It was a ten-kilometer run that wove through the streets of downtown Naples, Florida. We were there as a family for spring break and I decided that signing up for a race would offer a change from sitting beside the pool or playing board games with my brothers. I had two goals for the event. The first was that I wanted to finish. And the second was that I didn’t want to walk. I also really wanted a race T-shirt—so make that three goals.
It was exhilarating to line up shoulder to shoulder with the hundreds of other participants at the starting line. When the bullhorn sounded, I kept pace with the runners around me. People were standing on the sidewalk and in front yards cheering us on. I was running a little faster than I was used to, but I didn’t think anything of it. My adrenaline was pumping. Eventually, I started to notice the burning sensation in my chest and the fatigue in my legs, but I ignored them both. Even at fourteen, I knew that this was a race and that races were supposed to hurt.
But then the hurt became too much. The tightness in my chest made it hard to breathe and my legs started to feel like limp noodles. The people who’d been beside me were now way ahead of me. And instead of running, I was shuffling. But damn it, at least I wasn’t walking. Then a spry older gentleman with a red, white, and blue headband, perfectly bronzed skin, and obscenely short shorts wriggled his lean hips past me by speed walking. It was an image I would not soon forget.
I had run throughout high school, I’d completed marathons in college, and had gotten into ultramarathons in my twenties. When I thought about tackling the record on the Appalachian Trail, I knew I’d hike as much of it as I possibly could. That may seem counterintuitive, but I had learned by then, from the bronzed Floridian to the number of ultramarathoners I saw power-hiking uphill in 50k races, that a powerful hiking stride bested a tired run-shuffle any day.
Hiking is what worked for me in the long run, but I wasn’t sure that it would be the best approach for everyone. To this day, I wonder if a runner is going to come along and eclipse my record by several days. Even with all my experience, I’m still not sure what the best strategy would be. So I decided to ask a friend, ultrarunner, and scientist what he thought.
“We are built for walking,” said Shawn Bearden, professor of exercise physiology at Idaho State University. I got to know Shawn a while ago when he interviewed me for his podcast, Science of Ultra. Since 2015, he has produced dozens of conversations with the world’s leading physiologists, runners, sports psychologists, cardiologists, and nutritionists on the topic of ultrarunning. In short, he knows his stuff. And now it was my turn to pick his brain.
We started chatting about walking versus running, and Shawn immediately harkened back to early man to help me understand our physical design and drive. Homo sapiens followed herds and tracked wild animals. We migrated with the seasons to find more forgiving weather or suitable grounds for foraging plants. We fled on foot to avoid threats from neighboring nomadic tribes. If we needed to get somewhere—if we wanted to live at all—conditions demanded that we spend a large part of our lives on the move.
“Historically speaking,” Shawn said, “humans were active and moving 99 percent of the time. That’s how we evolved and that’s what our bodies expect. We have to start turning around this idea that exercise is a stimulus. For the majority of human existence, exercise was the norm or the baseline and being sedentary was the exception.”
The study of human history is the study of walking and the study of trails. The well-beaten dirt paths that wind through our landscape are responsible for dispersing goods and ideas. Where mountains, plains, and marshes separated us, trails linked us together. And for the majority of humans, the most efficient and sustainable method for getting around was to strike your heel on the ground, roll forward on the ball of your foot, and repeat that thousands of times a day. But there are times when walking just isn’t fast enough. So for both survival and 5ks, humans have developed the ability to run.
Obviously, we’re all walkers, but I always believed that we were runners, too. And I was convinced that Shawn, who was currently training for a hundred-mile race, would agree. Instead, he completely downplayed my efforts to paint humans as adept runners.
“We are built to keep going, keep moving; we are built mostly for walking,” said Shawn.
It turns out that our most effective evolutionary “assets” for running—our butts—are engineered more for sprinting and climbing than for long-distance races.
He continued, “The idea that our ancestors evolved to be long-distance runners is an extension of a misunderstanding of persistence hunting. Evidence suggests that the humans who tracked animals were only going about thirty kilometers or so in a hunt, and that they walked the majority of that distance. There was only a little running.”
“But . . .” I stammered, and hesitated a bit before treading on sacred ground.
“Aren’t we born to run?” Shawn interjected.
Before I could reply, he responded resolutely. “No. No, we have not evolved to be distance runners. We’re not even really built to run a marathon. We are born to walk fast and sometimes run.”
Shawn discounted the idea that Homo sapiens evolved from distance runners by defining persistence hunting—which involves chasing prey to the point of exhaustion—as a fast-paced walk with a few bursts of running.
If that strategy worked best for prehistoric man, I wondered if it would also be the best approach on a trail record. Maybe I could have completed the trail faster if I’d been willing to run the flat and downhill sections of the trail?
Shawn suggested that when covering long distances on trails, walking uphill is always the better approach. The same holds true for level ground. Running is obviously a faster way to go downhill but causes more damage. You want to move downhill as fast as possible with as little effort as possible, letting gravity do the work while you use your legs as subtle shock absorbers. So when carrying a pack—as on a self-supported or unsupported FKT—running downhill is a bad choice. Speed doesn’t outweigh the ability to keep moving injury-free.
I had once heard Warren say that a hiker can push all he wants to go uphill, but he should exercise caution and travel his own pace on the downhill. He warns: “Don’t try to keep up with the semi on a downhill and don’t punch on the breaks.”
Hikers and backpackers don’t use trekking poles to look like misplaced alpine skiers but to reduce the joint pressure and inflammation in their legs and hips. For hikers and runners alike the downhill can be harder on the body than a steep climb. But it takes a larger toll on the runners.
As Shawn points out, when you walk you always have one foot on the ground. If you’re running, then at some point your whole body is off the ground. Running forces you to lift your body up off the earth. The landing phase requires substantially different impact—greater impact. It also requires more energy—more calories.
Over a week or two weeks, it’s not much of a problem to pound and run and use excessive calories. But for weeks on end or several months, those very little things that happen with each step start to add up. And they can make a real difference. You have to run if you want to win hundred-mile races or complete them within the cutoff times, but for a two-thousand-plus-mile FKT the strategy has to change.
What Shawn and I didn’t discuss is that athletes are willing to wreck their bodies to reach the end of the trail. Scientifically speaking, walking is the more self-preserving method of covering more than two-thousand miles, but there are plenty of runners willing to sacrifice knee cartilage and future athletic aspirations for one FKT. Hikers might come out of the endeavor with less physiological damage, but that doesn’t mean that a runner won’t set the record.
I also need to emphasize that the topic at hand is entirely different from the modern objective of maintaining a healthy lifestyle. For 99 percent of folks, anytime is a great time to run. Getting out of our sedentary lifestyles and working up a sweat is healthy and important. But working up too much of a sweat on a record attempt can be a problem. This discussion is about the distance runners will travel before hikers pass them.
According to Shawn, “The two components of utmost importance when carrying your body a very long distance are wear and tear and energetics.”
I wasn’t sure of the exact definition of “energetics,” but its root made me think that Shawn was referring to output and exertion. For a layperson I wasn’t far off, but for a scientist like Shawn energetics encompasses the entire energy transfer process, including aspects such as thermodynamics.
Humans are able to walk all day because we evolved the necessary trait of regulating our body temperature with sweat. The human body’s ability to stay cool during prolonged periods of exercise historically helped us track and hunt animals. Today, it helps a construction worker put in a ten-hour day in the summer sun, or a farmer work his land for hours in high humidity, or an endurance athlete set an FKT. The key to staying out there is to work steady, not hard.
“Ideally, you want to be covered with damp skin or a thin layer of sweat that is evaporating,” said Shawn. “You don’t want to be dripping. Sweat that drips is precious fluid wasted.”
The more I talked with Shawn, the more I regretted vying for a record in the heat of the summer. The fact that I’d started in mid-June and finished in late July meant my body was having to work overtime to cool itself down, which led to a substantially higher average heart rate than if I’d been pushing myself down the trail during the cooler months.
On the other hand, summer afforded me more daylight than if I’d made a spring or fall attempt—and I didn’t have to deal with snow or ice. For a particularly strong night hiker or someone with loads of experience running ultras in the dark, daylight might not matter. But as a southern girl, I was conditioned to heat, and I think opting for daylight was still the right plan of attack. If I had to do it over again I might move my start date up a few weeks, but not months.
I had never before thought about sweat as “wasted fluid.” It seemed counterintuitive—or perhaps just countercultural. In America, we have a gym culture that idolizes perspiration. You hit the treadmill or pump iron hoping to work up a good sweat.
When I leave a workout dripping, I feel as if I have cleansed my pores, rid my body of toxins, and done something I can be proud of. But the stream of water running down our temples and the salt stains on our workout clothes cannot replace the benefits of a full day of motion. We cannot condense our primary identity as pedestrians into a thirty-minute workout.
I love to walk all day. And unlike most, I have been able to fulfill that desire for weeks or months at a time. But I have not been able to turn it into a full-time lifestyle. So for most of the year I’m going to go to Zumba, or Crossfit, or Pilates, or head out my front door for a run. With work and family, I can’t dedicate much more than forty-five minutes a day to my personal exercise routine (and that includes the postworkout shower).
But I can start my day with a few minutes of sit-ups or push-ups. When I’m at work, I can take a break and stretch, walk around the block, or find a flight of stairs to climb. And at the end of the day, when I want nothing more than to eat a bowl of ice cream in front of a twenty-minute sitcom, I can choose to be an engaged parent and follow my daughter around the house as she plays dress-up and builds pillow forts.
In our office-dwelling, car-driving culture it’s impossible for most people to sustain consistent movement throughout the day, but we can still sneak it into our routine in a way that reminds us of our body’s purpose and makes us feel much healthier.
I knew that athletes and researchers alike have pointed to the benefits of a relatively low and controlled heart rate for sustained aerobic activity, and that was another of the reasons I tried to hike my way into the record books instead of run my way in.
As he did with many of the ideas I put forth, Shawn hemmed and hawed about my theory.
“There’s no doubt heart rate is one indicator of how hard your body is working,” he said, “but it’s not necessarily an indicator of how fast you are moving. Other factors beyond pace can increase heart rate, including anxiety, sleep deprivation, negative mood, as well as hydration and body temperature.”
It also made sense that the stress of arriving at a remote road crossing and not spotting my crew or of stumbling across a bear or venomous snake in the dark would’ve caused my heart rate to spike even if I were at a standstill.
“Heart rate and energy expenditure can be disconnected,” Shawn said. “But typically, if you’re keeping your heart rate down, you’re keeping your energy output lower. Considering heart rate and wanting to keep it down is the right approach. The heart does well when it stays just above a resting level. It’s very comfortable doing that for an extended period of time.”
What’s normal for most well-conditioned athletes can be a red flag for the average person. When I delivered our daughter years ago, the nurse had to keep coming in to check on me because my resting heart rate was low and was triggering an alarm on one of the machines.
“Are you a runner?” the nurse asked.
“I’m a hiker,” I replied with a slight chip on my shoulder. But then I added, “I like to run, too.”
She gave me a cockeyed look, readjusted my blood pressure sleeve, and walked back to the nurses’ station.
Most serious athletes have low resting heart rates, but endurance athletes are seemingly just one level up from a corpse. For that reason, you would think runners would have incredible cardiovascular health. But David Horton had to undergo septuple bypass heart surgery despite logging more than one hundred thousand miles in his lifetime. And there are stories of well-trained marathoners and ultramarathoners dropping dead from heart attacks.
Toward the end of my FKT, there were a few times when I felt an intense ache in my chest. It never lasted more than a few minutes, but when it happened, it hurt—and it scared me. I’d never had chest pain before. I could typically walk through it or “walk it out,” just as I did with everything else. But on the last night of my AT record, I was hiking uphill with a friend pacing me a few feet ahead. It was close to midnight and I’d been on the move for nearly twenty hours when I started to feel the tightness in my chest. As I kept walking it became more difficult to breathe.
“I need . . . to . . . I need to . . . stop,” I panted.
I crouched like a catcher in baseball and put my head between my knees. It felt as if I had a cramp in my torso that was making its way from my heart to my lungs and up my windpipe, constricting everything as it went along. Trying to take a deep breath was like sipping a scalding-hot cup of tea. Tears ran down my cheeks. My friend knelt behind me massaging my shoulders and imploring me to take long, slow breaths.
The night air was filled with the sound of crickets, north Georgia barn owls, and my labored, wheezing breath. After a few minutes of crying and gasping for air, my inhalations became deeper and longer. As my chest filled with air, I could feel the flexibility and energy return to my limbs. I wiped my eyes with a dirt-covered forearm, unfurled from my stance like a fern frond, and nodded to let my friend know we could start hiking.
After my trail record, l worried that the stresses of it might have done permanent damage to my heart. So after my daughter was born, I decided to visit a cardiologist and find out. I had an echocardiogram and took a stress test and then I waited nervously for the results.
A few days later, I was hiking when I noticed I’d missed a call from my doctor. I pushed the play button on my phone and listened to the voicemail. “Don’t worry,” said the doctor, “you have a beautiful heart.”
When I told Shawn about the chest pains I’d experienced, he said, “It might have been a case of costochondritis. That’s basically an aching in your rib cage. It’s a common condition in athletes. There is no evidence today that endurance or extreme endurance pursuits cause any long-term damage to the heart.”
Shawn explained that what we’ve heard in recent news stories and in studies in which people have died from heart attacks during endurance exercise involved people who already had disease before they got into endurance sports. They started doing endurance because they were smokers and overweight and wanted to change their lives. They came in with some weakening of the heart muscle to begin with.
Shawn assuaged my fears and convinced me that extreme endurance is not going to create any long-term health problems that weren’t already underlying issues. And with that, the pendulum swung and I wondered if prolonged exercise resulted in any health benefits.
“My gut reaction,” said Shawn, “is that there aren’t any benefits to running or hiking fast over long distances versus moderate, sustained exercise.”
I was admittedly a little surprised. I hoped that a trail record might somehow be good for my health. I could even accept that it might have some negative ramifications. But I found it hard to believe that something so extreme could ultimately be a neutral endeavor.
In 2011, I walked my way to a trail record. And only once on my forty-six-day push did someone pass me. It happened one morning along the banks of the Potomac River as I followed the Chesapeake and Ohio Canal Towpath, one of the few places along the two-thousand-plus-mile trail where the tread resembles an urban greenway more than an amalgamation of jumbled roots and rocks.
I was cruising along at close to four miles an hour when a woman in a cobalt blue wind suit whom I assumed to be in her early seventies skirted past me in a steady jog. She was going just slightly faster than I was. As much as I tried to keep pace with her, I could hear her synthetic outfit swishing out of earshot and see her incandescent silhouette shrink to the size of a Smurf, then disappear.
I let out a little laugh when I think of a strong, fierce, record-setting hiker striding her way down the towpath only to have a wind-suit-wearing grandma swish by in a steady jog. The same thing happens when I think back to being a young, fit high school student who thought she was running when a sun-kissed Floridian in a headband waddled past her.
When I think about the people who might be able to surpass current trail records, runners and hikers both come to mind. Fast is fast, endurance is endurance. Perhaps athletes get too hung up on identifying themselves as either hikers or runners? Perhaps we all get too caught up in which category of exercise we ascribe to. At the end of the day, we’re all just movers—and the movement is more important than the mechanics.
There are a number of factors that can affect performance and recovery time. Gait, heart rate, and thermoregulation are a few of the big ones, but on my record attempt, I also wondered to what extent age, sleep, and nutrition affected a person’s performance.
When David Horton started his Pacific Crest Trail record attempt at 5:55 a.m. on June 5, he was fifty-five years old.
“Did you think you were at a disadvantage because of your age?”
“No,” he said. “Looking back now, maybe I was, but at the time I didn’t think so.”
“But you set the AT record when you were forty-one years old. Didn’t it feel different physically to set a record fourteen years later?”
“No, nothing felt different,” he responded. “I recovered just as well during the PCT record when I was fifty-five as I did on the AT when I was forty-one. I also trained just as hard at fifty-five.”
It was hard to believe that there was little difference in his record attempts, and I kept probing for some distinctions.
“Did it take longer to recover when it was all over?” I asked.
“Not really. I never thought about being old. Looking back, I think maybe I just didn’t try to go fast enough. The record’s been lowered several times since then.” (With that, Horton pinpointed a similarity between all former record holders. Once our hard-earned mark is surpassed, we all think that we should have gone a little faster.)
The FKT on the Appalachian Trail had a head start when compared with records on the Pacific Crest Trail. At the turn of the twenty-first century, the bar had already been set pretty high in the East, which was probably the result of being “the” trail for decades on end, not to mention meandering through the country’s most densely populated region.
In high-profile American sports there’s a concept called “East Coast bias,” according to which reporters focus more on the teams in the eastern region of the United States because game times line up TV viewership and readership is naturally more interested in what’s going on locally than on the other side of the country, where there are fewer fans and teams.
In recent years, a “West Coast bias” seems to have emerged in outdoor sports, placing greater emphasis on what happens in, say, the Rockies and the Sierras than in the Blue Ridge Mountains or the Adirondacks. Renowned downhill skiers have migrated from slopes in Vermont and New Hampshire to Utah, Colorado, and British Columbia. Rock climbers have flocked to Yosemite and Joshua Tree. Elite trail runners have done the same, and this has led to a growing interest in FKTs on the far side of the western continental divide. This tendency in outdoor sports over the past few decades has loosely paralleled prospectors heading west during the California Gold Rush. Between 2005 and 2016 the supported record on the Pacific Crest Trail has been lowered by a span of nearly two weeks. During that same period, the AT record has been lowered by only two days.
In 2014, a twenty-one-year-old cross-country runner from Boston College named Joe McConaughy headed west with some buddies and lowered the supported FKT on the Pacific Crest Trail to fifty-three days, which comes out to an astounding fifty miles a day.
“I was really surprised at that,” Horton said. “Joe was so young and inexperienced. All he’d done was run cross-country in college.”
I didn’t find it any more shocking that a twenty-one-year-old set the record than that Horton did it at age fifty-five. I figured they were both outliers and exceptions. It seemed to me that the perfect age for endurance might fall smack in the middle. But when I asked Shawn about this, his response surprised me.
“There’s no ideal age for endurance,” he said. “There are biological and physiological changes that would favor endurance and there are others that would work against it. For example, some cardiovascular declines might impair performance but at the same time there are adjustments happening in our muscles that are beneficial for long-distance events. There might be an ideal age for each person, but that can vary tremendously based on the individual.”
I was twenty-eight when I set the overall record on the Appalachian Trail. Warren was with Brew and me for the first twelve days of that record attempt. On multiple occasions he said, “Genius is wisdom and youth.” The statement was a bit cryptic, but I was pretty sure I knew what he meant: He was the wisdom and I was the youth.
There were fleeting moments when it seemed our partnership reached an ethereal level, but often his wisdom and my youth were at odds. We frequently disagreed on how far I should hike in a given day. He always wanted me to go a little farther, not necessarily to hike faster so much as just to sleep less.
“Sleep is an emotional need,” he would say.
After being sleep-deprived for twelve straight days and hiking through shin splints and bad weather in New Hampshire, I found that sleep did not feel as much like an emotional need as a physical necessity. My body ached, my legs were swollen and inflamed, my decision making was impaired, and I figured if I didn’t start getting at least six hours of sleep a night to rest my legs and my brain, I’d have a snowball’s chance in hell of continuing, let alone setting any kind of record. I was convinced that diving deeper into the sleep deprivation would result in either a serious physical injury or an egregious mental mistake.
Looking back, I think Warren was right. Maybe that’s because I have more experience—more wisdom—now. I know that I’ve referenced the birth of my daughter nearly as much as my FKT, but that’s because they’re both life changing, completely stressful, and entirely worthwhile, and they share a similar skill set. So . . . after the birth of our daughter, I spent a solid three months longing for meaningful REM sleep and feeling grateful whenever our baby slept more than two straight hours. Somehow, I survived and so did she.
I knew of Warren’s eccentric sleep patterns—that he would often drive ten plus hours through the night to get home after a contra dance in Pennsylvania or Connecticut, or he would sleep in his car in a McDonald’s parking lot or a Wal-Mart off I-81. But I was surprised when I started asking other FKTers how much shut-eye they required and found out they’d all needed less sleep on their record attempts than I did.
“You know what really pissed me off?” Andrew Thompson asked.
I could imagine quite a few things that would piss Andrew off.
“The fact that I was only getting five hours of sleep a night and that half the time I’d wake up and find myself lying half-naked in leaves and dirt outside my tent. I was so tired that when I’d wake up in the middle of the night to take a leak, I’d unzip my tent, do my business, then never fully make it back inside. My alarm would go off and I’d be all stiff and cold from sleeping on the forest floor. And I’d still be picking sticks out of my hair into the late morning and early afternoon. I was only getting a couple hours’ sleep a night and the sleep wasn’t even that good. I mean, c’mon. Really?”
I laughed. Fortunately, I’d never woken up outside my tent after a midnight pee break. But one time I did wake up inside the tent with Brew shaking me frantically.
“What are you doing?” he whispered urgently.
I mumbled something under my breath and he said, “What?!”
Then I spoke up and pleaded anxiously, “I can’t find the trail . . . I’ve gotta keep hiking.”
“It’s not time to hike yet,” he said. “It’s the middle of the night. Go back to bed.”
I heard what he was saying, but even as I answered him I was still in a fog, not fully aware that I was up on my knees inside my sleeping bag leaning against the tent’s nylon sidewall, both hands grasping for the zipper to the outside. In my dream, I was night hiking and had gotten desperately lost. My mind was racing. All I could think about was the time I’d wasted and the miles I needed to make up.
I’m sure that if I had gotten out of the tent, I would’ve started sleepwalking through the forest and gotten lost without a headlamp or reference points. (From that point on Brew slept with one eye open. And if I did wake up in the middle of the night to pee, he would stir and stay awake until I made it safely back to our tent.)
When I was chasing that record, I spent a large part of my waking hours fantasizing about sleep. I wanted it more than I wanted anything—more than fresh produce or a home-cooked meal, more than a cold beer or a glass of wine, more even than a hot shower or a soak in the tub. The one bargain I made with myself during the record attempt was that if I could keep going and make it to Springer Mountain, for the rest of my life I could sleep whenever I wanted and for as long as I wanted. And nothing would be taboo. I could take naps in the middle of the workday or indulge in consistent ten-hour nights on our memory foam mattress. Admittedly, my pledge went out the window as soon as I made it to Springer Mountain, but it helped me reach the finish.
Now that I had the opportunity to bend the ear of an expert, I knew exactly what I wanted to ask.
“Shawn,” I said, “when it comes to physical performance and endurance, is sleep an emotional need, or a physical one?”
Without hesitation or qualification, Shawn said, “It is 100 percent emotional.”
Damn it, Warren! That was not the answer I wanted to hear.
Shawn felt sure that sleep is not necessary for physical recovery, it is a brain need, but one the brain will make a priority during a multiweek or multimonth endurance pursuit.
I went on to discover that the primary reason for sleep is not to restore our body, but to restore our brain. If we want our body to recover, we need to stop moving, not sleep. In other words, sitting down will help your weary body as much as a nap will.
The catch is that when we get tired, our brain likes to play tricks and spread lies. We’ve already covered the angle of hallucinations, but the mind also likes to tell the body that it needs to sleep even when it doesn’t. Our mind can increase our perceived level of exertion, and a task will seem more challenging and exhausting than it really is. The brain is trying to force the body to give it what it needs. Sneaky brain! But our bodies can play a little trick of their own by resetting the perceived level of exertion with a ten- or fifteen-minute catnap.
I thought back to Captain Barclay, the famous British Pedestrian who walked a thousand miles in a thousand hours. During his successful feat, he walked one mile per hour—as dictated—and often snacked and took a ten-minute snooze before starting up again. In thirty-eight days, he never slept more than thirty minutes at a stretch.
I hate to admit it now, but there were a few blissful nights on my record attempt when I got seven hours of sleep. I feel like such a lush saying that! I should also point out that there were several occasions when I only slept three or four hours. It would be interesting to see an FKT attempt by someone who intended to get his or her rest in small increments, rather than clumping it all together at night.
To stay awake and alert, I usually had one or at most two caffeinated drinks a day. Usually Brew would bring me coffee from a gas station in the morning. The brown liquid wasn’t for taste or pleasure, it was merely a vehicle for cream, sugar, and caffeine. By midafternoon I might take a few swigs from a can of Pepsi or Coke from our SUV to help wash down my turkey and cheese sandwich or whatever I was eating for my second lunch. That’s right, I typically had a second lunch. And a second breakfast. And a second dinner. I was in full-on Hobbit mode. My job was to get as many calories in as I could in ten to fifteen minutes while Brew reorganized my pack and filled it with snacks and other items that I would need for the upcoming stretch.
I typically wouldn’t go more than an hour and a half without eating something. If you want to hike fifty miles a day, you’ve got to have fuel. I tried to consume upward of seven thousand calories a day, and it never felt like enough. By the time I set the record, I’d lost fifteen pounds and I positively abhorred chewing. Those final few weeks I kept asking Brew to find me food that I could swallow without chewing—things like high-protein energy drinks, milkshakes, and fruit smoothies.
Diet is another variable that each FKTer has his or her own take on. In 2006, Warren hiked the John Muir Trail in two weeks on a diet that consisted exclusively of Little Debbies. And here’s the kicker—Warren lost weight along the way.
While David Horton’s diet is a step up from Warren’s, on any given day I would almost be guaranteed to find double-stuffed Oreos, neon-orange Cheetos, and luminescent diet Sunkist in his pantry or pack.
“I try to eat relatively healthy off trail,” David said without a hint of irony. “On the trail, it’s a matter of getting enough energy or at least getting as much as you can. We’d try to find pig bars near the trail.”
“Sorry, pig bars?” I interjected.
“You know,” he said, “all-you-can-eat buffets. I could go there and eat as much as I wanted, load up on calories, and not waste much time. There are times on a record when you don’t want to eat. But you have to. I’m always glad when I reach the end because I can eat whatever I want whenever I want.”
When I visited Scott Williamson at his home in Truckee, California, he put out a carton of organic strawberries to complement the birdseed that he’d distributed for the Steller’s jays that dive-bombed his deck. “The carton says they’re organic, but to me they smell like some type of chemical or spray,” he said. A frugal hiker had just donated a six-dollar carton of organic strawberries to the birds because they didn’t smell right.
Scott said, “I try to eat a mostly whole-foods-based and mostly organic diet as much as it’s possible and practical. More so at home than on the trail, but as much as I can on the trail, too. I am not a vegan nor am I a vegetarian, although I was on a vegan and sometimes raw vegan diet throughout most of the first ten years that I hiked long distances.”
He continued, “My on-trail diet tends to be pretty repetitive. Breakfast, lunch, and snacks consist of homemade energy bars, beef jerky, some type of trail mix, whole grain fig bars, peanut butter, usually some kind of sweet like a natural licorice bar, and maybe a commercial protein bar. For dinner, I almost always eat dehydrated refried beans with corn chips and add olive oil liberally. I don’t generally carry a stove on my summer hikes. I prefer to cold soak my dinners to avoid cooking, partly to save weight and time and partly as a result of the explosive fire conditions we have throughout the West every summer.”
Knowing that dietary approaches among endurance athletes varied from raw veganism to Little Debbie, I was interested to hear Shawn’s thoughts on nutrition.
“When you’re covering such great distance, whether you’re running or walking and whether it’s supported or unsupported, you’re burning way too many calories to worry about the source of those calories. You just have to eat what you can keep down. After that, if you’re able to make choices, then you can start to focus on micronutrients.”
The human body has shown great resilience in functioning with a very limited diet through dire and demanding circumstances. During the Irish potato famine, much of the country’s population had to depend on what they could forage when their crops failed. This led them to subsist on plants such as stinging nettle, wild mustard, sorrel, and watercress for some time. Individuals who are forced to function on limited nutrients and calories tend to lose a lot of weight, but for a few weeks or months our bodies are able to adapt and persist with just about any food source.
The first thing I wanted when I finished my trail record hike was sleep—the second was a steak. I was constantly craving protein on the record hike, and that desire was strongest in the morning. I was weak and lethargic until I could get nuts, eggs, or a sausage biscuit in my system. Overnight my energy stores smoldered like a dying fire. Protein was the fuel I needed to start that fire back up again. Once it was going, I could throw almost anything on it to produce heat and energy.
When I mentioned my protein craving to Shawn, he reminded me of an interesting fact that I’d learned in middle school science class: Our muscles are constantly rebuilding themselves; the cells are continuously breaking down and replacing themselves. Within fifty to a hundred days the cellular makeup of a hiker’s bulging calf will completely turn over and you will have an entirely new leg muscle. Shawn suggested that the demands of a record attempt would accelerate that process. Because we need protein to rebuild muscle, it makes sense that I was daydreaming about steak, and fried chicken, and North Carolina pulled pork barbecue with vinegar sauce.
I felt vindicated in my carnivorous cravings but I also wondered about my endurance friends who are vegans or vegetarians. I wondered whether this high demand for protein might put them at a disadvantage. But according to Shawn protein is protein.
“There shouldn’t be any appreciable difference in processing animal protein versus plant protein as long as you are getting enough,” he said. Shawn went on to suggest that different people will have varying responses to diets and that what works well for one athlete might not be best suited for another.
I have witnessed elite hikers and runners perform at the highest level while proselytizing for a variety of different diets. Some forsake simple sugars and stick to the caveman diet; others prefer all-plant-based nutrition. I know many folks who have crossed gluten or dairy off the menu, and I have a few friends who believe that foraged and hunted foods are superior to the rest.
To be clear, I am not trying to identify the healthiest diet; this isn’t an objective look at the vitamins, minerals, and macronutrients on any food plan or a discourse on the environmental impact of specific food sources. Bookstores dedicate entire sections to those topics, and with good cause. What I am saying is that when it comes to long-distance performance, I have witnessed a variety of meal plans used effectively. I have also heard from many a thru hiker and runner that his or her diet is superior to the rest. But I think what that person means, or rather what that person should say, is that it is the best diet for that specific individual.
Shawn provided the science to support my theory that what works for one person might not be the best fit for another. He said that each individual has distinctive microbiomes that help break down and process the food that we eat. All those probiotics that they sell us at the health food stores and in our yogurt help the microbiomes do their job. But even with the help of a good probiotic, different people, with different microbiomes, will respond to different foods—differently. The flora and fauna in our gut are nearly as unique as our DNA and are directly connected to it. Genetic heritage, ethnicity, and gender are all factors in our microbial makeup.
The takeaway here is that when you are standing in front on the diet section at your local bookstore looking for the right nutrition plan, and you are overwhelmed by the variety of options before you, perhaps the best thing you can do is trust your gut.
The many different physical considerations that Shawn and I discussed made me wonder if there’s an ideal body type and constitution for endurance. And if there is, what would it look like?
Andrew Thompson shared with unyielding confidence that his physique was best suited for distance records. “My body type is directly in line with setting an FKT on the AT. I’m big, rugged, and can take a beating. If anyone should have an overuse injury it should be me! Nothing about my makeup suggests that I have covered tens of thousands of miles. My body can take it.”
Despite Andrew’s certainty, I still wanted to confer with Shawn. “If you were to build the ultimate long-distance athlete, what would he or she look like?” I asked.
“The person would have legs like tree trunks with muscles composed of slow-twitch fibers, the cardiovascular system to match, and he or she would be slightly less built above the waist.”
Andrew Thompson certainly had legs like a mighty oak, but I was more waiflike above the waist than he was. So I had him there! Strong legs and a diminutive upper body is a common physique for hikers and, on the trail, we jokingly refer to it as T-Rex syndrome.
I have always been a T-Rex; hiking just made it worse. I remember how self-conscious I was in high school when I developed calves instead of breasts. It took hiking to make me appreciate my body, my build, and my beauty. Plus, no one in his or her right mind messes with a T-Rex.
My awkward developmental years were exacerbated by the fact that I reached my adult height of seventy-two inches in eighth grade. It was inconvenient at school dances and when shopping for blue jeans, but as a tennis and basketball player I always believed that height was an advantage. I assumed the same would hold true on an FKT. Shawn, however, suggested that there would be a tradeoff for a long stride. As with the expression that the bigger they are the harder they fall, on an FKT, the taller they are, the more mass they have to move down the trail. In other words, long legs equals more bone mass and a heavier frame.
Hikers and backpackers are constantly trying to limit their weight. Regardless of whether it is in your backpack or on your body, the heavier the load that you carry, the more difficult it is to make miles. But you don’t want to start the hike looking emaciated. You need a few extra pounds and some extra energy reserves to expend along the way. It is best to start the endeavor with a svelte physique; not too heavy, not too light, but just right. The ideal way to start any endurance event is to look and feel healthy.
It was entertaining to go back and forth with Shawn trying to build the ultimate endurance athlete. I felt as if we had a children’s block toy in which the head, legs, and core of a figure could be twisted and combined in different ways. I would consider a medley that paired Andrew Thompson’s legs, my T-Rex upper body, and Scott Williamson’s core and diet. Then I would twist one of the blocks and contemplate a different approach altogether. But even if I could build perfect endurance athletes and give them ideal diets given their constitutions something uncontrollable could end their chance at a record.
A year or two after setting the record on the AT, I was experiencing tightness and pain in my right leg that made it uncomfortable to hike and very difficult to run. An MRI revealed a golf-ball-size cyst that had lodged itself behind my kneecap and limited the range of motion for my tendons, ligaments, and particularly my IT band. It was manageable on the record, but two years later I couldn’t walk around the neighborhood without discomfort. The lump wasn’t genetic, it wasn’t dangerous, but it did affect everything from my right foot to my lower back. The doctor said it needed to be surgically removed and that it would take six months of physical therapy before I could start running. That was a long, cranky six months.
Physical health is a gift and a privilege. It is important that we try to care for our health and protect it, but even so it can be taken from us at a moment’s notice. A large cyst is a relatively small matter, but a tumor, or stroke, or car accident can take away the freedom of movement that we take for granted. The lesson here is simple: Don’t take it for granted! When you are moving, whether at a leisurely pace or during intense activity, appreciate your body and enjoy its capabilities.
I might not always be physically able to hike upward of fifty miles a day, but I’ll always be glad that I did.
I didn’t contact someone like Shawn or pursue endurance research before I began my record attempt, because I wanted to listen to my body more than statistics and explore my boundaries without feeling like an experiment. I didn’t want to be told what I could or couldn’t do by someone who didn’t know me all that well.
The irony of diving into the science of endurance after setting a trail record is that my technique would probably look different if I were to attempt an FKT tomorrow. When I talked with Shawn, I reveled in the aspects of my strategy that seemed to be spot on. But I regretted other decisions, such as sleeping more than I probably should have. And if I had it to do again, I think I would opt for starting in the late spring rather than in the heat of the summer.
Nonetheless, I’m still grateful that I didn’t delve too deeply into the biomechanics and energetics of endurance before setting out on a record hike. The hypothesis behind my experiment was more personal than what could be postulated and studied in a lab, and my internal discoveries on the trail were more important than the physical results. Science can help us determine what is possible, but it takes a whole lot more than reason to deliver the evidence of endurance.
As I was winding down my discussion with Shawn, there was one more question weighing heavily on my mind—and I hesitated to ask it. If the answer was different from what I thought it was, I didn’t want to know I was wrong. But I finally worked up my courage.
“What about gender?” I asked a bit haltingly. “Do you think men have an advantage over women?”
Shawn’s answer was immediate and firm. “No. No, I don’t think that at all. There are many, many hypotheses about why a woman’s abilities would be equal to or perhaps even better than a man’s in a long-distance endeavor.”
You would think that I would have been most relieved to hear that endurance isn’t responsible for impaired cardiac function, but in reality I breathed a bigger sigh of relief hearing Shawn dismiss the gender gap. So much of my motivation, so much of my positive self-talk and confidence, came from telling myself that women were equal at endurance if not uniquely equipped for it. I would have taken atrial fibrillation over the feeling of inferiority. It felt liberating to know that I wouldn’t have to live with either one.
Once I heard that my sex was not a disadvantage, I quickly shifted to wanting to know if women might have the upper hand on long-distance pursuits. I started spouting off all the theories that ran through my head during the two-thousand-plus miles I spent convincing myself that I belonged.
“On my record, I kept telling myself that being a woman was a positive. I mean, relatively speaking we have smaller frames and less bone density so that means less weight to carry. But we also have a higher body mass index, which we usually hate because we end up carrying more fat than men do and have a muffin top above the waistline of our blue jeans. But on a record attempt, that extra layer of fat is an extra energy reserve that men don’t have. And a smaller frame also means we’d require less calories and water, right?”
I paused for a split second to take a breath, then continued. “Plus, we give birth. We give birth, Shawn! Don’t you think the evolutionary practice of carrying a baby for nine months and enduring labor pains would give us an advantage? Don’t you?”
Shawn gave a contrastingly measured response. “There are a lot of small factors that come into play,” he said. “What we find is that over time they all have a role and when we add them all up, we find that women are going to do very well at these types of endeavors.”
“Then at what specific distance do you think women become competitive?” I asked. “Is it five hundred miles? A thousand? What?”
“It’s hard to pinpoint an exact distance,” he said. “There are always many individual exceptions, so let’s talk about ‘on average.’ Men will do better at any type of strength and power activity because they have greater muscle mass and testosterone. When it comes to aerobic and cardiovascular activities, men typically perform better because their bodies carry more oxygen and they have higher VO2 max levels [the amount of oxygen an athlete can use, typically measured in body weight per minute].”
But as we go longer and longer distances, the ability of the heart to distribute oxygen becomes less of a factor. When we get to one thousand miles, VO2 max matters very little and the lactic threshold matters very little. The physiological differences are almost out the window. As I said earlier, humans were not born to run a marathon, let alone a hundred-mile race. And we certainly weren’t born to attempt thousand-mile FKTs.
Extreme exercise is a new thing. Our genes have never undergone any evolutionary pressure to get good at those distances or to create real differences between men and women for that sort of activity. Most likely there’s very little sex difference in these multiweek, maybe even multiday, events and beyond. Instead I think women’s real advantage might be psychological.”
It was a bit surprising to hear a physiologist say that the deciding factor in an extremely physical pursuit might in fact be mental. I asked him what he meant.
“Well, this is speculative,” Shawn said, “but it involves the evolutionary and biological role of females to birth and take care of children. Women are caregivers so they tend to think less about their own discomfort than about what they are doing for others. There is something that goes along with the capacity for motherhood and childbearing that allows women to just deal with chronic discomfort and engage in less self-pity. Honestly, in these types of endurance events I think that might be the tipping point.”
Shawn might have just simultaneously explained how I set the record and why I will never be able to do it again. When I was going after the FKT, I put my needs first for forty-six days. Brew understood that and supported it. In his words, I was allowed to be a diva.
Someone once asked if that made me feel selfish. I had to be selfish to set the record. On the other hand, it was a rare opportunity to fulfill my dreams, and I don’t feel guilty for seizing it.
After the birth of my daughter, a part of me knew that I would never again be able to pursue an extended FKT with success, but I couldn’t articulate why, until now. My transition to motherhood did not take a physical toll that would prevent me from setting a trail record, but emotionally I am no longer capable of putting my needs first for forty-six days. As Shawn suggested, I’m wired to be a caregiver. It’s my turn to help my daughter discover her dreams.
Ultimately, the question of gender and endurance is important to me not because I need to beat the boys—although I’ll admit I like doing it. The men who have come before and after me in these endurance pursuits have been and will always be some of my greatest friends and role models. But it bothers me that my efforts and the accomplishments of so many female athletes have been treated as a fluke or second-rate endeavor.
For the past five years, Brew and I have purchased the same Christmas gift for each other. We buy VIP tickets to the Southern Conference College Basketball Tournament in our hometown. It’s simple and there’s no wrapping involved. Then, during the second week of March, we watch about forty hours’ worth of live basketball over the course of five days. We immerse ourselves in the tournament to the point where I can hear whistles and buzzers in my head, long after we have left the gym.
At the tournament, I am struck by the fact that the women’s games have a quarter of the attendees, yet very often they are better match-ups. There is no dunking or high flying in the women’s competition, but because the teams can’t rely on their physicality to win, they rely instead on strategy and teamwork. When you compare men’s and women’s athletics, there is no difference in intensity, dedication, or drama. The primary contrast is in pay and prime time.
We live in a culture that promotes men’s sports and places women on the cover of athletic magazines as swimsuit models. And it takes individuals like Serena Williams, who has defied sexism, racism, and ageism throughout her twenty-year professional career, to show us that women’s athletics can be as captivating as the men’s draw and that women deserve equal exposure and equal pay.
This matters to me because I am a woman, an athlete, and clearly a Serena Williams fan, but most of all it matters to me because sports are a microcosm of our culture. Being a business professional, scientist, or politician doesn’t have anything to do with bench presses and wind sprints, but females are still underrepresented and underpaid.
It’s a well-reported and often-ignored fact that in America, women earn 70 percent of what their male colleagues take home, and we struggle for equal representation in high-paid professional pursuits, boardrooms, and politics. In our country’s 240-year history, we have never had a female president.
The main reason that I love sports is that they can bring together different groups of people and redefine what is possible. The fact that I became the first woman to set the overall record on the Appalachian Trail holds some significance in the world of FKTs, but more than that I hope that it demonstrates that the farther we go, the longer we play this thing out, the closer we will come to the tipping point.