Sleep high, train low has not always been the operative training mantra. As far back as the 1968 Mexico City Olympics, many endurance athletes believed that the best approach was to move someplace high–the Alps, Albuquerque–where they could live full-time and train in thin air. In the 1990s, however, researchers Ben Levine and Jim Stray-Gundersen revealed a major drawback to this live high, train high approach: Though chronic hypoxia does increase an athlete’s red blood cell count, it also makes it impossible to exercise hard enough to get into peak condition.
One of the first high-profile adopters of the altered approach was the U.S. national long-track speed skating team. Three years before the 2002 Olympics, team members moved to Utah. During the days, they trained at Salt Lake City’s relatively modest elevation of 4,700 feet, which supplied enough oxygen to train hard. But during the nights, they slept in Park City, a nearby ski area whose 7,000-foot elevation provided sufficient lack of oxygen to stimulate physiological changes. The net effect: The team’s six skaters racked up eight medals.
But what if you can’t move to Salt Lake, or Boulder, or Chula Vista, or the handful of other sports meccas that offer both high and low altitudes within easy commuting distance of each other? You can train hard and hope for the best (see "How to Reach Your Peak," page 107), or you can move hypoxia to you: Numerous studies have shown that exposure to simulated altitude triggers the same physiological changes enjoyed by those who live at real heights.
What has proven more difficult to demonstrate is whether such changes translate into actual performance boosts. In terms of sports performance at sea level, several studies have found big gains in both aerobic capacity and long-distance running times. Other studies, however, have failed to show any such lift. One possible reason: In some athletes, the oxygen-carrying benefits of increased hematocrit may be offset by the increased "thickness" of their blood. "We know that people who live year-round at 10,000 feet are more predisposed to blood clots and heart problems," says Schoene. "The blood can get sludgy."
What is clear: pre-training helps when you’re headed for high altitude. Most researchers agree that the right dose and duration of hypoxia reduces AMS symptoms. In a 2007 study, Natick Institute researcher Stephen Muza concluded that soldiers exposed to a simulated altitude of 14,000 feet for three hours a day for one week had a strong probability of avoiding AMS when deployed to high places. And such pre-inoculation significantly reduced the performance dips seen in unacclimatized soldiers.
In my own case, the R&D manager at Colorado Altitude Training suggested I spend at least three weeks in my hypoxic chamber once I cranked it up to peak elevation. After setting it up in July, I spent the first night at 4,700 feet. Over several weeks, I upped the altitude by 500 to 1,000 feet per night until I reached the highest the pump would allow, just shy of 12,000. There I stayed for the rest of the summer.
In my fully oxygenated daytime hours, I set my sights on another critical piece of pre-trip training: resuscitating leg muscles that had become nearly vestigial from decades of swimming as my only exercise. In cardiovascular terms, I’m in pretty good shape for my age. But being fit in the pool is not the same as being fit on dry land. As exercise physiologists have long noted, athletic training is incredibly muscle-specific. Well-exercised muscles adapt in a host of ways–from increasing the size and number of mitochondria to developing extra capillaries. Rarely used muscles, on the other hand, don’t need, and hence don’t get, this turbo-charge.
The gold standard measure of aerobic fitness is called VO2 max–essentially, the highest volume of oxygen your body can use to do work. Oxygen use is partly dictated by the amount you can breathe in and load into your bloodstream via the lungs. It is, however, much more related to how much oxygen your skeletal muscles can metabolize. Elite marathon runners, swimmers, and other endurance athletes all tend to have high VO2 max levels–especially when measured during the activity they’ve trained for. A marathoner measured on a rowing ergometer, on the other hand, will not score nearly as high.
In terms of mountain climbing, I was as well-adapted to the task as a manatee. In order to have a chance on Elbert, my climbing muscles–legs in particular–had to be resurrected.
To inaugurate the new regimen, I drove to a local gym where a marathoning friend agreed to give me a graduated treadmill test. This began with a five-minute warm-up at an easy 5-mph pace. The grade then increased from one to three percent, and the speed by 0.3 mph every 90 seconds. After 20:30, I gave up. I was jogging at 7.1 mph, and my heart was beating 171 beats a minute. My saliva felt like Elmer’s Glue.
At my friend’s suggestion, I began walking gradually longer distances on flat ground. Then I started climbing the stairwells at a gothic skyscraper at the University of Pittsburgh. The first time I attempted to walk up all 43 floors, I nearly collapsed. By the end of the summer, I could make it up and down four times without stopping.
About eight weeks into my program, I tested my progress with a 13-mile hike through the hills and valleys of the Pennsylvania coutryside. With breaks, it took five hours to finish, and I needed a half roll of duct tape for blisters. Still, I’d made the distance without expiring–by far the longest my little legs had ever ferried me at a single stretch. Shortly after Labor Day, I retested myself on the treadmill. This time, I lasted 24 minutes and made it up to 7.7 mph before being forced to stop with a heart rate of 176.
I’d done more land exercise over the course of the summer than the previous 10 summers put together. In mid-September, when my flight finally departed Pittsburgh for Denver, I still wasn’t sure I was ready for Elbert. But I did know I was as ready as I’d ever be.