Outside Magazine, November 1994
Strategies: Extracting Knowledge from Thin Air
By Dorothy Foltz-Gray
Even before you're reunited with your luggage, the stress of altitude is undermining your ski vacation. The drop in atmospheric pressure between home and resort--the average flatlander lives at 500 feet, and the average western ski area sits at 7,000 feet--means it's harder for the oxygen to saturate the blood. So you're panting through your trip to deliver oxygen to your needy
muscles and brain.
You can't acclimatize from home, but you can prepare for the stresses. Starting a week before your trip, drink a gallon of water a day; you lose a lot of moisture every time you exhale, you'll be doing a lot of that at high altitude. And get to bed at a decent hour--many people experience insomnia at higher elevations.
For the first couple of days at the ski area, try not to spend a lot of time above the 8,000-foot mark, where the thin air can be truly dangerous for the unacclimatized (see below). If you get a headache from the drop in oxygen pressure, which causes the arteries in the brain to expand, Johnson and other experts recommend popping some ibuprofen.
Altitude: Sea Level
Atmospheric Pressure: 760 (mm of mercury)
Blood Oxygen: 97% saturation
Higher Truths: The partial pressure of oxygen in the atmosphere is an abundant 110 millimeters of mercury. It drops with each foot of altitude.
Altitude: 5,000 feet
Atmospheric Pressure: 630 (mm of mercury)
Blood Oxygen: 95% saturation
Higher Truths: Now your breathing has quickened and you're expelling large amounts of carbon dioxide, which starts to weaken your natural defenses against painful lactic acid buildup.
Altitude: 8,000 feet
Atmospheric Pressure: 564 (mm of mercury)
Blood Oxygen: 92% saturation
Higher Truths: You're at a point where the oxygen in your blood has dropped precipitously. Altitude sickness--with symptoms of insomnia, nausea, vomiting, and severe headache--now becomes a threat.
Altitude: 10,000 feet
Atmospheric Pressure: 523 (mm of mercury)
Blood Oxygen: 85% saturation
Higher Truths: What the atmosphere is no longer providing, your heart has to make up for: It's working 12 percent harder than it does at home.
Altitude: 12,000 feet
Atmospheric Pressure: 483 (mm of mercury)
Blood Oxygen: 83% saturation
Higher Truths:The average high-altitude base camp is somewhere between 12,000 and 14,000 feet. If you've climbed any faster than 1,000 feet per hour--certainly feasible if you're riding chairlifts--expect motor skills and intellectual functions to falter temporarily.