Every year at Thanksgiving, John Nickles travels with his family to the Big Island of Hawaii. And every year, as the beaches fill with languid tourists and umbrellaed drinks, Nickles jumps in the ocean and swims. In 1996, he found himself more than half a mile off the island's coast. Arms wheeling, body undulating with the current, he suddenly looked up with consternation and started to dry-heave. Later, he shrugged it off. "I got seasick," he said.
When he recovered, Nickles churned through the last 2.5 miles of his 6.2-mile swim, emerging in first place with a new course record of two hours, 19 minutes, 57 seconds. He then ran up on the beach, climbed on to his bike and raced 90 miles. The next day he rode 174.1 miles, and the day after that he ran back-to-back marathons (52.4 miles).
Nickles isn't crazy. He's an ultraman: a new breed of athlete that is stretching the bounds of human endurance to its snapping point. The Hawaii Ultraman, now recognized as the sport's world championship (other events include Ultraman Canada, to be held in British Columbia on July 31-Aug. 2), is perhaps the world's most grueling professional endurance race. It is not, however, the only one. Dozens of Herculean contests span the globe, and a daunting percentage of them are in the United States. The Badwater ultra-marathon in California's Death Valley pushes runners through 135 miles and 8,600 vertical feet of torturous terrain; and the RAAM (Race Across America) bicycle race challenges participants to traverse the country coast to coast as quickly as possible. The record, set by Rob Kish in 1992, is a mind-boggling eight days, three hours and 11 minutes, and racers have been known to rig up bungee-cord contraptions that keep their heads upright once their neck muscles have given out.
American athletes tend to be an obsessed bunch, but the trend toward endurance extremes has sounded alarms in the medical community. In the short term, common consequences of prolonged, strenuous exercise include tendonitis, stress fractures and chronic fatigue syndrome. But research is beginning to show that by racing ever farther and longer, athletes may also be putting themselves at risk for a host of chronic diseases, even cancer.
There's some irony in the suggestion that exercise should come with a health warning, but according to Liz Applegate, Ph.D., a nutrition professor at UC Davis and the author of "Eat Your Way to a Healthy Heart: Chocolate and 99 Other Foods to Help Your Heart" (Prentice Hall Press), the news that extreme athletes may be compromising their health shouldn't be too surprising. "People can do it," Applegate says, acknowledging the feats of athletes like Mark Allen -- a greyhound of a triathlete who has captured the Hawaii Ironman six times -- "but the body wasn't meant to do it."
The physical demands professional ultra-athletes put on their systems are tremendous. Their lifestyles are built fastidiously around repetitive, exhaustive exercise and they sequester themselves into regimented cycles of training, eating and sleeping. "Realistically, a professional ultra-distance athlete doesn't have a job," says Applegate. She estimates that ultra-athletes can burn as many as 5,000 to 6,000 calories a day (the average person burns 1,600 to 2,200 calories). Ultra-athletes might be capable of approximating their physical ideals, but maintaining superhuman athletic prowess is a biological impossibility.
"There are a bazillion stories of athletes who have developed chronic fatigue syndrome," says Applegate, singling out overtraining as the most common ailment among the ultra-athlete set. Like a car pegged at 8,000 rpm, the human body can run at maximum for only so long. And when it cracks, it spirals into a state of fatigue and viral vulnerability. "Some athletes have a cold for four weeks," Applegate says. "They think, 'I'm in good shape. I'll shake it off.' Well, they're not in good shape. They don't realize that this amount of exercise is a huge stress on the body and could compromise their ability to fight off something as simple as a cold."
For now, events like the Hawaii Ultraman are overwhelmingly dominated by men ("Women may have more sense," quips Applegate); the 35-strong starting list for last year's Ultraman contained just three female participants. But women may be more susceptible to the ravages of prolonged ultra-athletics than men. Prentice Steffen, the physician of the Mercury professional cycling team, estimates that more than 75 percent of female endurance athletes experience irregular menstruation. "It's almost an automatic thing when women exercise too much," he says, adding that because of this, female endurance athletes run a higher risk of contracting bone-mineral diseases like osteoporosis later in life.
Neither gender, however, is immune to two of the most significant consequences of a lifetime of ultra-endurance. One, foot-strike hemolysis, affects distance-obsessed runners. With each stride, a runner is literally rupturing red blood cells, which over time could lead to a strain of anemia.
The other, termed oxidative stress -- an insidious process that attacks the body at a molecular level -- has piqued considerable alarm among sports doctors. Oxygen is the human body's life force, but it also generates unstable molecules called free radicals. According to Applegate, free radicals corrupt healthy cells, mangling them by stealing electrons and potentially turning them cancerous. Natural antioxidants like vitamins C and E (which are prevalent in fruits and vegetables) combat oxidative damage, and are abundant in most healthy eating habits. Exercise, however, increases the body's oxygen intake. Under moderate strain, the body's biology can easily adapt, activating its stores of antioxidants and extinguishing "oxygen fires," as Applegate calls them.
Ultra-endurance athletes, though, have bounded into extreme physical terrain, and the distance and intensity they demand of their systems has crossed dangerous biological lines. At maxed-out exertion levels, an athlete is gulping monstrous levels of oxygen and is turbulently circulating it with a heart rate approaching 200 beats per minute. According to Applegate, when an athlete repeatedly pushes him or herself through prolonged exhaustive training sessions, the body can no longer keep up. "Now you've got a three-alarm fire going on," she says. "And your body can't put it out."
It is currently impossible to establish a definitive link between extreme athletics and cancer. The ultra-marathon trend is too recent for a study, and, unlike a pack-a-day smoker who develops lung cancer, it is impossible to positively identify an athlete's cancer as exercise-induced. Molecular tests, however, have proven the damaging effects of oxidative damage, and Steffen doesn't dismiss the theoretical possibility that cancers in athletes like Lance Armstrong -- an American cyclist who developed testicular cancer in October, 1996, but has since recovered and returned to competition (he won the 1999 Tour de France bicycle race on July 25) -- could have had their genesis in over-exercise.
To squelch an oxidative inferno, it would seem that ultra-athletes need
only scale back the scope and intensity of their training. The problem,
however, is that ultra-endurance is not just a sport. It can also be an
addiction. When Nickles describes his experience at the Hawaii Ultraman,
his sentences are punctuated with words like "honor" and "respect." He
speaks adamantly about the "spirit" and "camaraderie" of the race, and he
admits that his very existence centers on the pursuit of peak
ultra-endurance fitness. His athletic goal, he says, is four-fold: "Win
Ultraman, do RAAM, a 100-mile running race and swim the English Channel."
"These are not laid-back people," Applegate says. A high percentage of
ultra-endurance athletes are obsessive compulsive, according to Applegate, who contends
that they use the challenge of mega-distance as an avenue where they can
pursue and control their worlds.
Doctors also stress that athletes don't have to be ultra-marathoners to
suffer the effects of overtraining. Carlton, a cyclist and runner who
declined to use his last name, spent years defining his self worth through
exercise. More than a day or two of rest could produce depression and the
illusion of acute muscular atrophy. At 19, he had reached what he took to
be an athletic pinnacle. He was training relentlessly during the week and
racing on the weekends. After a few weeks of mediocre workouts and general fatigue, he went to the doctor for a check up. At 6 feet tall, he weighed just under 140 pounds, and was told that he "needed to eat more red meat."
"I was anemic and chronically fatigued," he says.
Carlton, however, has a fairly common athletic profile; his workout habits
are on a par with many exercise-conscious Americans. Ultra-endurance
athletes undertake training regimens that are exponentially more demanding than Carlton's toughest week. So if his system could be ravaged by overtraining, how could an ultra-athlete's lifestyle ever be classified as
"It's not healthy," Steffen says. The human body, however, has amazing
regenerative powers, and Steffen maintains that even if athletes compete at
ultra-endurance levels for 10 years, they still have the bulk of their
lives left for repair. "It's as if you smoked for 10 years in your 20s or
30s and then stop," he says. "By the time you reach your 40s and 50s, it's
as if you never smoked. It's the same for extreme athletics."
Ultra-athletes, unfortunately, don't always stop. Of the 35 participants at
last year's Hawaii Ultraman, 29 were over 30, and 16 were over 40.
According to Nickles, who is 35, ultra events have become the domain of the
older athlete. When triathletes and other endurance athletes are no longer
competitive in traditionally-distanced events, they often up the ante by
going ultra. Nickles likens his own ultra obsession to an athletic
biological clock. "I can hear it ticking," he says. "I know I only have so
many years left to be in this kind of shape."
Growing evidence, however, suggests that an athlete in the throes of an
ultra-distance addiction is accelerating the aging process, and Steffen
contends that ultra-athletes need to become proponents of moderation.
"Anything in the extreme is not good," he says, lumping exercise with
traditional vices like smoking and drinking. "The body and its joints only
have a certain lifetime," he continues. "They're using up too much too soon."