RARE AIR.(The Talk of the Town)(training of mountaineers)

There isn't much a guy can do to improve his physical fitness while sitting all day at a desk, except maybe to squeeze a rubber ball, jiggle a leg, or eat a lot of bananas. This was the problem that confronted Richard Wiese, the president of the Explorers Club, as he planned an expedition to climb a pair of volcanoes in Mexico. His biggest obstacle would be the altitude (the volcanoes, Orizaba and Iztaccihuatl, are, respectively, 18,700 and 17,343 feet above sea level), and the fact that he would have very little time to become acclimated to it. Even seasoned climbers need weeks to get used to the thin air. Wiese, experienced as a mountaineer but encumbered by a nine-to-five job, would have merely days.

His solution, the fruit of some Internet poking around, was to have an altitude chamber installed in his office, on the third floor of the club's headquarters, a Tudor-style mansion on the Upper East Side. The chamber, made by a company called Hypoxico, is a transparent plastic box, nine feet by six feet by seven feet--the size of a walk-in closet. Amid all the club's artifacts (Admiral Peary's sledge, Thor Heyerdahl's globe, Peter the Great's side table), the chamber seems out of place, like Pei's pyramid at the Louvre. The air inside simulates that which you would breathe high in the mountains: it contains less oxygen. A month before leaving for Mexico, Wiese moved his desk into the chamber and began conducting his daily business at the equivalent of thirteen thousand feet. This was, as far as he could tell, "the first instance of an altitude chamber being used in an office setting." (And it may not be the last: it's not hard to imagine oxygen, like carbohydrates and sleep, becoming a desirable deprivation among members of Manhattan's executive class.)

At first, the mountain air got to him. He couldn't stay in the chamber for more than a few hours at a time, and in telephone conversations with the club's board of directors (who took to calling him B.O.B., for Bubble Office Boy) he found himself growing irritable and woozy. But after a couple of weeks he began to adjust. Thirteen thousand feet felt like flatland.

On a recent afternoon, just prior to the Mexico trip, Wiese made room in his chamber for a sea-level visitor. Wiese is a youthful forty-six, tan and sandy-haired. He wore a Beretta shooting sweater and cargo pants. Once he closed the door, the percentage of oxygen in the ...