Wednesday, July 29, 2009

Mile-High Club: Do Oxygen Tents Boost Athletic Performance?


When a zipper shows up in a mid-life crisis, there’s usually a private investigator outside a motel window with a telephoto lens.
But the only thing I was cheating on was my athletic destiny. Or I thought I was.
The zipper in this case was of the floor-to-ceiling variety, enclosing me in the oxygen-starved weirdness of an altitude simulation tent from Colorado Altitude Training. There, in the basement, wedged between the bookcase and my 7-year-old’s wooden railroad empire, I spent four weeks of not-so-restful nights trying to sherpa-charge my cardiovascular system for a road bike race up Colorado’s 14,420-foot Mount Evans.
Altitude-simulation tents are enclosures hooked to the back end of an oxygen generator, so they suck O2 out of your air instead of pumping it in. They don’t duplicate the air pressure difference — you would need a steel tank for that — but an athlete’s cardiovascular systems is still forced to work as if it were at altitude, causing the proportion of oxygen-carrying red blood cells to rise. The tents, which start at $4,000, are thus sold as a quick ticket to the “live high, train low” regimen.
“This is certainly the way to prepare for it!” Colorado Altitude Training CEO Larry Kutt told me. Kutt has no medical training, but he quickly sketched out a program for me. Already acclimated to Boulder, I could ramp up the elevation quickly. He told me to start at 6 or 7 thousand feet and work my way up to 11 or 12 thousand. I would practically fly up Mount Evans. “The entire podium at the Tour de France [in 2008] was people using CAT equipment,” he exclaimed.
The tent CAT loaned me was one of the company’s higher-end models. Setup was simple but controlling the “low-oxygen environment” was trickier. The unit delivers the oxygen-thin air in liters per minute. A hand-held meter gives the percentage of oxygen while a graph keyed to the starting elevation matches that percentage to an approximate altitude. But there is no gauge that measures oxygen level. Keeping it right meant waking up several times a night to check the meter and adjust the flow.
I took some “before” numbers into the tent with me. After a trip, the Boulder performance Lab, I found my wattage at lactate threshold, the point where your body can’t clear lactic acid from the bloodstream, was 248, high enough to qualify me as “elite,” at least among 45-year-olds.
My VO2 Max (the amount of oxygen the body can process) was a respectable 51 liters per minute. If the tent increased the proportion of red blood cells, those numbers, and my performance, should go up.

After 10 nights in tent, I upped my average speed on one 8-mile uphill ride by 1 mph, to 15.4 mph, shaving 1:32 off my best time, but that was perhaps due more to favorable tailwinds than anything else. On another climb, my best pre-tent speed had been 11.9 mph. A week before the race, after two weeks in the tent, I spun a disappointing 11.4 mph.
I went into the last week with growing doubts. I wasn’t sleeping well. With the iffy oxygen-level controls, I would wake in the middle of some nights at the elevation equivalent of 13,000 feet. The next morning I’d wade through pedal strokes in a hangover-like stupor.
Two nights before the race, I decided to sleep tent-free. I wanted as much quality sleep and oxygen-aided recovery as possible. Turns out I needed it.
The Bob Cook Memorial Mount Evans Hillclimb starts at 7,555 feet and follows the highest paved road in North America, past the timberline and into the gasp zone above 14,000 feet. Pilots are required to carry supplemental oxygen a 12,500. And I’d been sleeping at 12,000.

didn’t start feeling better until a week later when I went back to the Boulder Performance Lab. We were looking for the “after” results and we found them. They just weren’t what we expected. The difference was one watt out of 248. My VO2 max was up, climbing from 51 to 58, but my legs weren’t using that oxygen to any effect. I wasn’t faster. I wasn’t stronger.
But I was surprised.
Rick Crawford wasn’t. A Durango-based coach at Colorado Premium Training, Crawford has worked with ultra-elite athletes like Lance Armstrong, Levi Leipheimer and Mount Evans record holder Tom Danielson. Crawford has “a lot of experience with tents” but says he doesn’t recommend them. “I have never asked an athlete to buy a tent,” Crawford says. “They just end up having them.”
Crawford discounts anything beyond a placebo effect, claiming that the low-oxygen environment hampers recovery and robs the athlete of sleep, a primary component of any training program. “Why am I starving my athlete of oxygen that he needs to recover?” Crawford asks.
And even believers can be cautious.
Karen Rishel, a 44-year-old family practice physician, who races road and mountain bikes on weekends, had a custom tent made. She sleeps in it with her husband in their El Paso home. “All the advertisements say four weeks and it should make a real difference,” she notes. “I think it is cumulative and takes longer.”
Her experience in the first month matched my own. “For the first month that I was in the tent I would wake up in the morning and feel like crap, every day,” Rishel says, though in the end, she says, she got stronger and faster.
“A lot of people end up having an expectation that you are going to get tremendous results right away,” Rishel says. “It’s a long-term journey with cumulative effects.”
That may be true, but I’m not sticking around long enough to find out. I bid farewell to the tent and returned to restful sleep. Turns out neither science nor body hacking nor a generous dose of tech were going to help me achieve a single minded two-wheeled fantasy.
I just couldn’t cheat on my athletic reality.
(Images by Beth’s Gallery/ Picassa, Colorado Altitude Training, and bicyclerace.com
source:www.wired.com

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