Switchback Travel Reviews the Hypoxico Sierra 100: Training for Denali at Home
November 03, 2026 | By Stan Pillman
In June 2026, Switchback Travel Senior Editor Chris Carter got the kind of invitation mountaineers dream about: film an athlete's climb of Denali's West Buttress to 20,310 feet with only about a month to prepare. He lives near sea level in Chattanooga, Tennessee, and had no time to travel west to acclimatize. His solution was the Hypoxico Sierra 100 Altitude Generator.
Four Weeks of Sleeping at Altitude
Carter paired the Sierra 100 with a Head Bivy on his bed. Four weeks out, he started at a simulated 5,000 feet and raised the setting about 500 feet per night, topping out at 13,000 feet. A fingertip pulse oximeter helped him track his blood oxygen, and a steady hydration and electrolyte routine kept headaches in check as he moved past 8,000 feet. New to the method? Start with our guide to sleeping at altitude.
The Results on Denali
On June 22, Carter stood on Denali's summit "breathing and climbing with remarkable ease." He didn't feel the altitude until above 17,000 feet, went the entire climb without a single headache, and called it one of the fittest he has ever felt at altitude.
What the Full Review Covers
- How Hypoxico generators lower oxygen to simulate elevation
- Step-by-step Sierra 100 setup and altitude adjustment
- Choosing between the Sierra 100, Everest Summit II and HYP 123
- Practical tips on noise, tent space and sharing a bed
- Renting versus buying
- The ethics of training with an altitude simulator
His take: for climbers and 9-to-5 athletes on tight timelines, altitude generators "improve accessibility and equity in the outdoors."
Read the full Hypoxico Sierra 100 review on Switchback Travel →
Planning your own climb? Explore altitude generators, altitude tents and rental options, or learn more about pre-acclimatization.
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