This story appeared in ESPN The Magazine's Oct. 18, 2010, issue. Subscribe today!

AFTER RACING NEARLY 140 miles, first through the ocean, then across the blackened lava fields of Kona, Hawaii, Julie Moss crested the final hill of the 1982 Ironman Triathlon alone in front, hovering near delirium. She was also about 45 seconds from becoming, as she remembers it, "the ultimate, giant, chocolate mess."

Since the 16-mile mark of the marathon, Moss, a vivacious 23-year-old with a shock of red hair, had managed to hold back the field as well as the considerable contents of her intestines. Suddenly, like a beacon in the Pacific twilight, a Sizzler steak house appeared, cool and inviting, atop the hill on Palani Road. Almost a half mile from the finish, Moss had a gastronomical gamble to make. She gazed back and forth, evaluating her options -- relief by way of the Sizzler bathroom in front, an evaporating lead in the inky darkness behind -- all the while contemplating the ultimate unspeakable taboo almost every elite athlete faces at some point.

Do I stop? Or go?

Exhausted and dangerously dehydrated, Moss was losing control of her body with every step. But she trudged on, pushing herself toward victory. The legs went first. A quarter mile after passing the Sizzler, Moss wobbled, then her knees buckled inward and she telescoped to the ground like a dynamited building. The moment she hit the pavement, her bowels cut loose, emptying against her will. The torrent breached her dainty, light-blue running shorts and moved down her legs, where the hot, acidic fecal matter stung her skin and the putrid stench tattooed the inside of her nostrils.

Overwhelmed by the feeling of helplessness, Moss sat on the road for more than two minutes. She was panicked, embarrassed, horrified. And yet, in some inexplicable, scatological way, she felt transformed. As she explains it now, "What you're weighing, looking at the bathroom and the finish line, is: Can I ask more of myself, can I give more, can I suffer more? That's what sports is. How fine of an edge are you willing to dance on? What kind of a mess can you live with? But you learn the answers only if you're willing to go beyond your limits to that Star Trekkie place, where, you know, no man has ever gone before."

What Moss is getting at is the ugly, smelly, essential Tao of Poo.

We can exhaustively explore every aspect of athletic life -- victory, defeat, violence, racism, drugs, brain damage, paralysis, death -- but nothing reveals as much about the physiology, psychology and sociology of sport as the excretory experience of athletes.

Of course, such is the sacredness of our relationship with our bowels that we're all programmed to pretend no one ever poops (or writes about it), despite the fact that every day on this planet, we humans produce 1.5 billion pounds of the stuff. The plain truth is, we all poop. Even athletes. Especially athletes. One of the sports world's last unspoken dirty little secrets is that this perfectly normal bodily function has a profound effect on all levels of competition. And the more you understand the way exercise impacts the intestinal tract, the more you'll wonder how any athlete ever manages to hold it in. In fact, a lot of times, they don't. A survey by the Oklahoma Foundation for Digestive Research, released in 2000, found that 72 percent of conditioned athletes have suffered from lower-intestine distress.

In other words, athletes poop their pants (or shorts) far more often than you realize. And once we kick open the stall of shame and secrecy that surrounds the topic, it turns out most of them have a poop story (or two) to tell. "It sounds crazy and gross, but I think a lot of athletes will read this and go, 'Oh, god, yes, I know that feeling,'" Moss says. "They'll understand that in my situation it really was a simple, even an easy, choice for me. Yes, I was willing to s--- my pants rather than stop."

SOME OF OUR greatest champions have danced on the edge that Moss tumbled over. In the 1997 NBA Finals, a severe stomach flu forced Michael Jordan to play through extreme bouts of vomiting and diarrhea. His 38 points (with multiple grimaces) led the Bulls to a pivotal Game 5 win against Utah. At Wimbledon in 2001, Serena Williams was suffering from a stomach virus and ran off the court during her quarter-final match with Jennifer Capriati in the decisive third set, after pleading with the chair ump for a timeout. "I can't hold this," Serena cried. And this summer, some of the New Orleans Saints began referring to their championship tilt with the Colts as the Super Bowel because of the unpleasant events that transpired before kickoff. "An NFL pregame locker room can be the most god-awful scene you will ever see or smell," says former Saints linebacker Scott Fujita, now with the Browns. "We are moments away from the Super Bowl, the highlight of our athletic lives, and pretty much everyone is in the bathroom just absolutely blowing up the stalls."

Yes, everybody poops. Even your favorite athlete. The difference is, sometimes they do it in front of millions of people. Phillip Toledano for ESPN The Magazine

In the doomsday parlance of pants pooping, let's put the Saints at a relatively safe Defcon 5 -- that's military lingo for "normal readiness" -- Williams at Defcon 4 and Jordan at a potentially messy Defcon 3. When you see surfer Kelly Slater suddenly paddle away from a big wave at Banzai, he's likely at emergency level Defcon 2, creating an organic flotilla that surfers call fish food. As Slater puts it, "The secret for going No. 2 in the ocean is being down current from everybody. You don't want to go up current at your friends. That's rude."

Which brings us to the main subject of this story: Defcon 1, or "maximum readiness," which is what Moss experienced in Hawaii on that fateful day 28 years ago. Defcon 1 crosses all sports. In 1996, Boston Marathon winner Uta Pippig hit the tape tanned from tummy to toes in diarrhea, the aftereffects of what marathoners lovingly call runner's trots. And then there's Tony Stewart, whose own close encounters of the No. 2 kind are part of NASCAR lore. During a race at Watkins Glen in 2004, an ailing Stewart radioed his crew to get a relief driver ready, pronto, because he was having major league meat sweats. A few minutes later, the radio crackled with a sheepish update from Stewart: "Never mind." After he won, everybody on Victory Lane waited more than 10 minutes while Stewart detoured to his trailer to change race suits. (When he finally met the media, he joked that he'd been fixing his hair.) So just how mortified was he? We can only wonder. While Stewart has spoken candidly about the fatal risks of his profession, he refuses to talk about his one-car accident. As a topic of conversation, dying in a race car is okay; pooping in one is not.

When Moss painted the pavement in Hawaii, cameras from ABC's Wide World of Sports rushed in for a close-up. The klieg lights gave the scene a stark, horror film feel as millions watched in collective shock. But it wasn't the mess they were riveted by, even though Moss had soiled herself three times on national TV, in an era when the word crap might have been bleeped. What everyone really wanted to see was what would happen next. "Rising through the muck, literally, was this primal, spiritual notion in me that I had never experienced before," Moss says. "It said, 'Get up. Keep moving. Win.'"

After standing and staggering another 200 meters, Moss dropped again and began crawling the final 200 meters toward the tape, only to be passed, cruelly, 10 feet from the finish line by ... well, no one really cared. Moss' courageous finish made her an instant, and enduring, icon in the booming field of endurance sports. Right after the Hawaii race aired, she flew to New York for an interview with Jim McKay, who touted her performance as one of the defining moments in sports television history.

And yet, a sense of shame -- and danger -- lingered. When Moss was invited to appear on Late Night With David Letterman, she declined, afraid the interview would devolve into one long recounting of her stupid human trick. One Carolina Panthers player remains the butt of jokes after his own unfortunate incident in 2007, when he lost control of his bowels after taking a vicious hit to the gut, while wearing the home-white pants, no less. To this day, teammates and opponents make farting noises when the receiver catches a pass, so it's no surprise that he hasn't publicly addressed his embarrassing fumble.

Michael Jordan famously fought through intestinal discomfort in a 38 point effort and a Game 5 win in the 1997 NBA Finals. Getty Images

Anyone in that Panther's shoes has good reason to be cautious, says David Inglis, a professor at Scotland's Aberdeen University and the author of A Sociological History of Excretory Experience. The way Inglis sees it, there is no single act that can both ostracize and infantilize a person like public defecation. "This is a highly problematic issue with athletes, one that dares not speak its name," he says. "On some level, athletes whom this happens to are seen as engaging in a form of cultural deviance."

Another poop author puts it more bluntly: "If you walked into a bathroom and saw John Elway in a stall taking a big dump, you'd never think of him the same way again," says Dave Praeger, who penned Poop Culture and serves as editor in chief of poopreport.com. "Nothing can knock a superhuman athlete down to earth as quickly and severely as poop. That's the power of poop."

In other words, poop is the great equalizer. The fact that it happens so frequently, and publicly, to athletes in action creates a toxic paradox that, just like a triple bacon gordita, we don't exactly know how to process. This entire issue of The Magazine is proof of how we, as a society, regard athletes' bodies as the ideal representation of the human form. We hate and hide defecation because, as Freud said, it reminds us that we aren't, in fact, pure spiritual beings; we inhabit physical forms that are flawed, organic and, in the case of the New Orleans Saints, pretty dang nasty.

So if you're appalled, or even just grossed out, by a magazine full of beautiful athletes interrupted by a story on poop, good news: It means you're normal. We have survived as a species, in part, because millions of years of evolution have us hardwired to be repulsed by things that can cause us harm. And make no mistake, poop is our enemy. As a conduit for disease, human waste has killed more people than war, genocide and nuclear weapons combined. A single gram of feces can house 10 million viruses, 1 million bacteria, 100 parasite cysts and 100 worm eggs. Even more shocking is that the Natural Resources Defense Council estimates that 90% of the world's sewage ends up untreated in lakes, rivers and oceans. We might not want to talk about it, but we're already swimming in it.

The inclination to deny our own filth is as old as man himself. Around A.D. 200, a group of Gnostic Christians went so far as to argue that even though Jesus was a man incarnate who ate and drank, he absolutely, positively, 100 percent without a doubt did not poop -- and certainly never in his tunic. Thirty years of constipation for their savior may be in keeping with Gnostic theology that earthly life is full of suffering, but come on, we all know different.

Jesus pooped.

Tim Tebow does too. LeBron James poops. Derek Jeter, Maria Sharapova, Drew Brees -- they all poop. Most of these stars will never have a Julie Moss moment or even a Serena Williams scare. And if they did, it's highly unlikely they'd ever talk as openly about it as Paula Radcliffe does in discussing her own Defcon 1 incident. The British distance runner and Nike spokesperson was four miles from winning the 2005 London Marathon when she stopped suddenly and darted to the side of the course. Radcliffe had been losing time for several miles because of gastrointestinal disturbances -- the kind that, according to one study, affect 83 percent of marathoners and that are usually preceded by gaseous outbursts that runners call walkie-talkies.

Radcliffe's solution? She simply placed one hand on a metal crowd barricade for balance, used the other to curtain her shorts to the side and perched, precariously, over her shoes. Then, as they say in England, she proceeded to "have a poo" right there on the street and in broad daylight, within two feet of a startled spectator. "I didn't really want to resort to that in front of hundreds of thousands of people," she says, unfazed. "But when I'm racing, I'm totally focused on winning the race and running as fast as possible. I thought, I just need to go and I'll be fine."

She was fine. Radcliffe finished her pit stop, adjusted her shorts and floated through the next four miles to win by more than five minutes and set a world record for a women-only marathon. The most telling part of the whole scene was the BBC announcer's description. He insisted Radcliffe was just stretching out "a cramp" during her brief detour. Cheeky bastard.

Afterward, there was no public backlash. That's a tribute, Inglis says, to the supreme cultural power of sports. He offers this scenario: If Radcliffe had been out on the street in London a day earlier, walking with her kids or her dog, and stopped to relieve herself on the sidewalk, she would have been arrested, shunned and dropped by Nike within an hour. But the fact that she did it in the middle of a race made it not just okay but, in some weird way, kind of awesome. "You truly begin to get a sense of how influential sports are only when you realize it's one of the few activities where society's willing to override such strong feelings about defecation," Inglis says. "We make something so taboo acceptable, for a little bit at least, because it's being done for the sake of what we see as a higher sporting ideal."

It took more than a decade, but that's how Moss eventually came to understand her own accident. In many ways, her journey on this topic is our journey as well. She started out humiliated and overwhelmed by the unspeakable grossness of what happened, unwilling to discuss it even with friends or family. But the more she matured as an elite athlete -- she was enshrined in the Ironman Hall of Fame in 1994 -- the more she understood and accepted the catastrophic consequences of her choice to continue. (Nowadays, the 52-year-old Moss, who lives in Santa Cruz, Calif., and does commentary for triathlons, is more embarrassed by the ill-fitting trucker hat she wore during her infamous race.) "I've discovered that winning is not as fulfilling or as profound as when you are completely taken to your physical limit and, maybe, dumped off a little on the other side," she says. "There is a sacredness to that place. Although there are probably ways to get there that are more graceful than what I did."

Moss' "chocolate mess" was the result of a gastrointestinal chain of events that began, innocently enough, with prerace jitters. These are a part of the nervous system's evolutionary fight-or-flight response meant to prepare us for grave challenges. But they also tend to send the stomach and intestines into overdrive. In a pre-energy bar era, Moss drew her in-race nutritional needs from an almost laughable concoction of a Snickers bar, bananas and water. (Early in the race, she actually discarded the half-melted Snickers because she was worried about looking untidy on TV.) Over the course of 140 miles, this diet contributed to electrolyte imbalance, glycogen debt, dehydration and exhaustion that all lowered the strength and effectiveness of the muscle contractions Moss needed to "hold it."

But the main culprit was this: The moment Moss began to exercise, her body started shunting blood away from nonessential systems, like digestion and waste, in order to feed the heart, lungs and muscles with nutrients and oxygen. This is known as exercise-induced ischemic colitis, and the result is a black, bloody, swollen colon, like the one that now has the attention of Michael Dobson, the director of a colorectal surgery center in Charlotte, N.C., who is holding up a disturbing endoscopic image from The American Journal of Gastroenterology. The owner of this colon, an ultra-marathoner, had denied proper blood flow to his intestines for so long -- because of natural, but extended, shunting -- that the tissue inside his colon began to die and perforate. An extreme example, yes, but anytime blood is removed from the colon by exercise, as Dobson explains, water and other material that should have been absorbed along the way instead pass rapidly to the rectum. There, spikes in volume and pressure trigger nerves in the sphincter that emit urgent warnings to the brain. In less scientific circles, this is what is known as prairie doggin'.

Usually we are granted an accommodation response, where the accordionlike walls of the rectum expand to handle the extra volume. The sensory response inside the sphincter resets while we pull over to a rest stop or fake an important phone call to bolt from a staff meeting. But athletes don't have this option while they're competing, and here's where things get interesting -- and messy.

The sphincter has the final say in these matters, and it is controlled by a unique double ring of muscle tissue that acts like a clip around the bottom of an inflated balloon. The outer ring is made up of voluntary muscle fiber that's under our conscious control. But the inner, more dominant ring is made up of involuntary tissue and regulated by the independent neurological gatekeeper found in the reflex centers of our spinal cord. The battle for control over the sphincter, then, is a smaller version of the constant tug of war between the sympathetic and parasympathetic divisions of the nervous system that athletes deal with when pushing their limits.

The ability to deflect signals from the brain that say, "We're tired, this is dangerous, we should stop," is a common trait among elite athletes. In a rather cruel twist of fate, though, that same quality also makes them more susceptible to crapping their pants. Jocks are taught to ignore pain and fight through fatigue, and they often mistake the rectum's initial accommodation response as a sign of total control over the area. But when the rectum fills to a certain point, for a certain amount of time, there's nothing anyone can do to hold it back.

In an act of superhuman subabdominal strength, Moss willed her sphincter closed for almost 10 miles -- 16,000 desperate strides. But then the sphincter made the decision for her. Moss didn't poop her pants; her exquisitely named pudendal nerve did. "The real miracle is that this doesn't happen more often with athletes," Dobson says. "A giant lineman in the NFL strains as hard as he does to hold back a 300-pound pass-rusher for an entire game, and 99.9 percent of the time his sphincter works properly and holds back all that pressure."

Meet Robbie Tobeck, the other 0.1 percent. The former NFL center, who retired in 2006, spent 13 seasons in the league, the final seven as a cornerstone of the Seattle Seahawks offensive line. In 2001, Tobeck and the Seahawks traveled to Washington to face the Redskins. Late in the week, he had come down with a wicked, explosive stomach virus; by game day he had lost 10 pounds, as well as a roommate, after guard Steve Hutchinson was mercifully allowed to seek shelter away from the sounds and smells emanating from Tobeck.

"I had pretty much blocked this whole awful experience out of my mind until you called, so thanks," says Tobeck, who co-owns an insurance company in Bellevue, Wash., and hosts his own outdoor radio show on Seattle's ESPN 710AM. "This stuff happens way more than people realize. Every time you hear a player got 'snot bubbled,' you have to know the same thing happens on the other end, too. You just get hit so hard, you lose your control for a minute."

The Seahawks were a precarious 3-3, so after a three-word pep talk from coach Mike Holmgren -- "Tough it out" -- Tobeck downed all the Imodium he could find and willed himself onto the field. There, trainers stashed spare pants and a bucket for Tobeck to poop in behind the team bench. He made it through his first snap to quarterback Matt Hasselbeck and was holding off 335-pound defensive tackle Dan Wilkinson when running back Shaun Alexander ran into him from behind. In Tobeck's delicate condition, that was enough to cause him to Jackson Pollock his pregame meal all over the back of his uniform. And yes, Tobeck still calls it the worst moment of his career, even worse than suffering two Super Bowl defeats. "When you're trying to push every last bit of your ability out of your body, stuff's gonna happen," he says. "It's not a badge of honor. In football, you're just expected to go beyond your limits. I was lying on the ground, thinking, What do I do now? Then I was like, 'Heck, it's only Hasselbeck -- I'll stay in the game.'"

The next play called for a shotgun snap, but crowd noise at FedEx Field forced Hasselbeck to snuggle up nice and tight under center. The epic mushroom cloud of funk had set in with Tobeck's linemates and even with the Redskins -- on his return trip to DC two years later, Tobeck found a bag of Depend adult diapers in his locker -- but at the time, Hasselbeck didn't fully grasp the origin or the extent of the situation until a few minutes later, when a bug-eyed trainer ran up to him near the Seahawks' bench.

"Hey," the guy yelled into Hasselbeck's ear. "I'd stop licking my hands if I were you!"

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