More than five hours into a 24-mile run-already more than twice as long as I had ever taken to race that far-I looked straight up at the next stretch and resignedly began walking again. So went Stage 1of the Himalayan Run & Trek.

One-hundred miles over five days in the Himalayas-yes, those Himalayas-daunting, but doable, I thought some weeks before during an easy 10-mile run along the C & O Canal. Sure, the air would be thin, racing in India would pose obvious logistical issues, and mountains by definition would include some serious climbs. But I had twice run the JFK 50-mile ultramarathon, winning once, and I figured I could manage a five-day mountain stage race that amounted to not much more than one week of high mileage.

Turned out I miscalculated on just about every point. Surprisingly, running at altitude of up to 13,000 feet was not so bad-five days of acclimatization surely helped. As for the race logistics, aid stations with a glucose drink, bananas, and baked potatoes helped, but experienced stage-race ultrarunners, of whom there were many at the event, wore CamelBaks filled with electrolyte drinks and carried PowerBars and energy gels. I hand-carried only a water bottle and completely bonked on that eye-opening first day.

The mountains, however, provided the biggest shocker: the uphill climbs were obviously difficult, in bike terms, hors categorie climbs that simply could not be run. Downhill was, for me, worse, as my inclination toward survival mandated caution while picking my way over giant cobblestones. Experienced downhill runners trusted their wilder instincts and took their chances with gravity. My times and place suffered badly on every downhill stretch.

Trekking is not a word Americans use, but the European runners were not surprised that so much of the event included hiking. I learned later that several of them chuckled at my early impertinence, more properly simply foolishness, after I ran, however slowly, the first few uphill miles of Stage 1. By the last mile, I was using the stone roadside barriers as anchors to pull on and hoist me toward the finish. In one day, we had climbed a total of some 10,000 feet, dropped 3,700, and my average pace was more than 15 minutes per mile. I finished seventh of 58 runners but I did not think I could run the next day.

I hoped a hot shower and comfortable bed would revive my body and my spirits, but cleaning up was limited to a bucket of warm water and sleeping arrangements consisted of a dormitory room filled with a dozen or so beds. A generator provided minimal electricity but no heat, and temperatures on the mountain dipped toward freezing once the sun set.

Honest-to-God sherpas, however, provided plenty of plain but nourishing food, notably a salty potato soup of which I must have slurped a dozen cups in my depleted and dehydrated state. As other runners made their way into the cabin and huddled around a charcoal-burning can, we shared tales from the trail and began to feel better. A few runners had abandoned that stage and caught a ride to our outpost in the jeep of shame-no one blamed them. But nearly all, including a 69-year-old English grandmother, completed the arduous trek. And so at 6:30 the next morning, everybody started anew.

"Adventure racing is not for idiots," Himalayan Run & Trek director C.S. Pandey exhorted weary participants without a trace of irony midway through the event. "You've got to keep thinking every step of the way."

Pandey, a well-meaning martinet during our week together, was certainly correct. Successful ultrarunners solve problems during a race. Not math problems or even figuring out splits, which is difficult toward the end of any race. But they find solutions to the more subtle physical and psychological challenges that inevitably present themselves over the course of a long run. Issues include pace, when to walk, how to tack through and navigate gullies so deep they scraped elbows, when and how to manage caloric intake, monitoring physical reserves, and other critical mental adjustments, and mean the difference between racing and just finishing. Such strategies simply overwhelmed this canal and bike-path running American, so mostly I just finished.

All of which begs the question: why travel halfway around the world to abuse oneself so mightily? Fair enough, and I will avoid cliches about a sense of accomplishment and camaraderie fostered through pain, arm-in-arm finishes, and plenty of beer shared with runners from around the world-all true. Side-trips to Delhi, Darjeerling, and the Taj Mahal provided more obvious benefits.

Running 100 miles in the Himalayas is not for everyone. But travel, like running, is about living hard and expanding one's realm of experiences. I sit now in front of my PC and look with awe at the photo reprinted with this story and envy that runner, hardly believing it is me. Spectacular views of Mt. Katchenjunga and Everest were alone worth the grueling plane trip. If running is our purest form of self-expression, then testing ourselves through racing in a challenging foreign environment is plumbing our very depths. Do not ask the question and you will never know the answer.