I Used a Hypoxic Tent for 23 Nights to Prepare for a Climbing Trip. Things Didn’t Go As Planned.

I lay in a tent in the Canadian Rockies, drifting in and out of fitful sleep. Suddenly, I couldn’t breathe. I gasped for air but the tent’s slack walls had covered my mouth.

“Arghhh!” I screamed. I flipped the small plastic tent off my head and watched it crash into my bedroom wall. Breathing heavily, I flicked on my bedside light and remembered where I was: not on some Himalayan peak—as I’d hoped to be in a few days—but at home, where I was intentionally sucking the oxygen out of the air.

Scowling at the tan and blue fabric laying on the floor, I realized my error. I hadn’t secured one of the tent poles into a corner pocket while assembling it that evening. The dome had slowly flattened over the course of the night, eventually covering my face like an empty garbage bag.

I gathered the hypoxic tent off the floor and stuck the poles back into place. The bad sleeps would be worth it, I reminded myself, when I arrived in the high Nepali town of Namche pre-acclimated and ready to climb. After all, I was going to be there with some of the world’s best alpinists. I didn’t want to slow them down.

After triple-checking that the tent’s poles were firmly in place, I closed my eyes and tried to forget the feeling of being smothered alive.

What the heck is a hypoxic tent?

Altitude tents, also called hypoxic tents, are amazing tools for the alpinist with limited free time. Using a generator, hypoxic tents filter out some of the oxygen in the air and pump it into a sealed-off container to mimic the effects of sleeping at a higher altitude. Over the course of several weeks, the climber sleeping in a hypoxic tent will become acclimated to a much higher elevation than where they currently live. This shaves weeks from their total expedition length. These tents have become increasingly popular with climbers aiming for extreme altitudes (8,000-meters-plus) on short-timeline expeditions—but they are also expensive and a nightmare for claustrophobes.

Hypoxic tents have long interested me, as someone who loves climbing on big alpine faces yet struggles to take the month (or more) off work required to safely acclimate and then climb a 6,000- or 7,000-meter peak. I’ve made the most of this restrictive work schedule for years, enjoying successful trips to low-altitude mountains like the Chaltén massif in Patagonia, Washington’s Cascade mountains, and remote corners of British Columbia. But when the opportunity presented itself to finally climb a 6,000-meter peak in Nepal—in only two weeks, door-to-door, thanks to a hypoxic tent rental—I couldn’t pass it up. The North Face was launching a new line of alpine equipment and invited me to try it alongside some of their athletes on Lobuche East (6,119m/20,075ft).

What it was like sleeping in a hypoxic tent

Aside from the one terrible night when the tent collapsed, for the three weeks leading up to my trip, I slept soundly in my artificially hypoxic bedroom. The generator hums like a loud white-noise machine, and since you’re somewhat sealed off from the outside world, I was less likely to check my phone and start scrolling when I woke up in the middle of the night. Though I used a torso-sized tent (29” long, 37” wide, 25” tall), larger hypoxic tents can fit over queen- and king-sized beds, and even the bed’s surrounding floor space. I also tried out Hypoxico’s “Training Mask” during a night while I was travelling and couldn’t easily set up the tent, but I found it too invasive to really get much sleep. Its neoprene felt stiflingly hot for the midsummer night, and the mask’s stiff air-valve tube prevented me from rolling onto my sides.

Lukas Furtenbach, owner of the Himalayan outfitter Furtenbach Adventures, who organized my rental, advised me to sleep a minimum of 140 hours in the tent to prepare for Lobuche East, ideally in seven-hour increments to maximize my acclimatization. A few nights I woke up naturally after six hours of rest, so I spent another hour reading in my little plastic bubble. It was a weird way to start the day.

Each morning and night I recorded my resting heart rate and blood saturation levels with a finger-pulse oximeter to ensure I was gaining altitude appropriately, averaging 200 meters “higher” each night. I didn’t want to see spikes in either data point, which would signal I’d overreached the night before. After a particularly hard workout or big climbing day in my local mountains, Furtenbach suggested I take the night off from my hypoxic tent, or drastically lower the altitude I’d be sleeping at, to let my body fully recover. It felt strange to watch my altitude tick upwards each night for three weeks, nearly reaching 4,000 meters by the end, all the while tucked away in my home at 800 meters in Canada, tending to my garden, training in the local climbing gym, and attending work meetings as usual. Was I really ready to blast off to Nepal?

Preparation ≠ success

One morning, as I peeled open my hypoxic tent and checked my phone, I saw news headlines from Nepal. Its government, long criticized for favoring corrupt elites, had banned 26 social-media and messaging platforms. Nepalis saw the ban as an attempt to silence their rising dissent and protested. Government forces fired live rounds into unarmed crowds, killing at least 19 people. Protesters stormed government buildings in response and lit them ablaze. In two days, the Nepali government had been effectively toppled. My flight was cancelled indefinitely, and I was left with the shameful disappointment that happens when personal ambitions clash with a global reality far more notable and devastating.

I thought back to the 23 nights I’d spent in the hypoxic tent and realized how much I had learned from the acclimatization experience. I had essentially slept higher than I’d ever slept before—my previous highpoint was 3,000 meters midway up a limestone ridge in the Rockies—and was logging up to nine hours of quality rest each night. I felt like I had power to burn while climbing and running on local mid-2,000-meter peaks. I was outpacing fit partners while carrying a heavier pack.

As I packaged up my tent rental and prepared to ship it back to Furtenbach, I actually wished I could hold onto it for another couple of months. I had a trip to Alaska planned for that spring, and though I planned to climb a lower-elevation peak (Mount Huntington, 3,731m/12,241ft), the ability to show up completely acclimated to the summit elevation would undoubtedly make the experience safer, faster, and more fun. On a much taller mountain like Denali (6,190m/20,310ft), a hypoxic tent would be even more useful.

For the first time since receiving the tent, I Googled how expensive this setup really was. I was surprised. A complete one-person kit (including generator, head-bivy tent, and oximeter) cost $2,161 to own. Not a cheap solution by any means, but not the most absurd, either. If you are in a financial position to afford expeditions to high-altitude peaks, over a lifetime of climbing trips, the per-night cost might even be considered downright reasonable compared to the rest of the trip’s expenses.

I finished taping up the cardboard box and stared at it one last time. Had I gone to the Himalaya, I would have had a decidedly different experience than those acclimating the old fashioned way: in person, on the ground, one cold night at a time. Was I a fool for streamlining my moments with nature?

I once wrote about climbing with just the bare necessities in Patagonia. Tiny tents, shared sleeping bags, and leaving it all behind. Midway through writing that article, I realized I was preaching a practice I didn’t entirely agree with: that mountain climbing should only be experienced in brief, fervent bursts. I also realize I am doing a similar thing here: Stay attached to your phone and job and real life for as long as you can, until you must weather the inconvenience of actually going out into the world.

But maybe I had been thinking about it all wrong. If you are not one of the privileged few who can leave a job and a spouse for months at a time and still have something to come back to, then isn’t it better to experience the magnetic pull of the mountains for a few weeks rather than never at all? And isn’t it better to show up to basecamp prepared, drastically reducing the chances you’ll need to rely on your fellow climbers, or brave mountain-rescuers, to save your sorry, unacclimated butt?

For me, hypoxic tents are currently out of the budget. But I certainly won’t think less of the climber who shows up to the mountain of their dreams having used one.

The post I Used a Hypoxic Tent for 23 Nights to Prepare for a Climbing Trip. Things Didn’t Go As Planned. appeared first on Climbing.