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How Athletes Reap the Benefits of Altitude Training Without Actually Moving to the Mountains


January 17, 2020 Sports and Outdoors : Health & Fitness By Photo by Josh Wray

Join me, if you will, in 2010. No, this isn’t some Facebook 10-year challenge. It’s 22-year-old me riding a bike over Wolf Creek Pass in the Race Across America. I’m young, fit, and convinced I am invincible. I am also breathing through what feels like a straw. Someone is paying for me to ride a bike fast, and I can barely get up the hill. Nobody is paying me to walk in silly shoes, so I get to the top before handing over to the next rider, but I certainly considered a job in accounting halfway up that climb. I was born and raised in the UK, where the highest point is the summit of Ben Nevis at 4,413 feet. I haven’t been there. Wolf Creek pass tops out at 10,856 feet. As I crested the summit, it felt like all 6,443 of those extra feet were standing on my throat.

Unless you were born and raised in the mountains, you may have noticed that visiting them can be a pretty weird experience. Put aside for a second the strange proliferation of Subarus and the fact that literally everyone makes the same joke about waiting five minutes if you don’t like the weather: what I’m concerned with is the weird wheezing, surprise headaches, and difficulty sleeping even though you’re a thousand miles away from the noise and distraction of the city. 

That, my friends, is altitude.

Despite the fact that altitude makes you suck at just about everything, including moving, sleeping, drinking and breathing, athletes the world over have been voluntarily subjecting themselves to it for decades. Why? I assembled a crack squad of athletic boffins to find out. My A(ltitude) team included physical therapist and ultra-runner Tim Tollefson and exercise physiologist and coach Andrew Kastor, who both live and train in the thin air endurance mecca of Mammoth, California, as well as Neal Henderson, head of sports science for Wahoo Fitness, and Chessa Adsit-Morris, USATF trail marathon champion and Ph.D. candidate. I had no doubt that together, they could demystify the connections between altitude, air and athleticism. And that if I dug a little deeper, I could learn how to score the benefits of altitude exposure without moving to Mammoth or Boulder.

Altitude Training, Explained

Photo: Josh Wray

First, it’s important to understand what it is that makes you feel bad at altitude. Henderson explains: “What happens as you get farther from sea level is that particles in the air become less densely packed as a result of lower pressure and this partial pressure of oxygen (PO2) is reduced because of the reduced barometric pressure.” In layman’s terms, it’s not just that there is less oxygen in the air, there is less air in the air. The result in the body is that your blood oxygen levels drop. Note that this isn’t the same as your breathing being restricted. You still breathe normally at altitude — in fact you breathe more — you just get a little less oxygen in every lungful. 

If you spend long enough at altitude, much above 7,000 feet according to Kastor, your body responds to this low level of blood oxygen by creating more erythropoietin, the fabled EPO that you probably read about on the same day you threw away your little yellow wristband. The increase in EPO is one of a host of adaptational changes including decreased lactate, increased concentration of capillaries and blood vessels in muscle, increased aerobic enzyme concentration and increased red blood cell mass. Together, these involuntary tweaks allow altitude-adapted athletes to produce greater aerobic power for longer periods of time versus those living and training at sea-level. 

A recent study of Tibetan villagers who live their lives at around 15,000 feet revealed that they have 10 oxygen-processing genes not commonly found in lowland populations. And Egan Bernal, the winner of the 2019 Tour de France, hails from Bogotá, the 8,660-foot capital of Colombia.

Long story short, they can get more oxygen to their muscles and do more work. And yet. “Even fully acclimatized individuals to a given altitude are still impacted by that altitude — just to a lesser degree than a non-acclimatized individual will be,” Henderson is quick to point out. “Also, there is a significant variation in how a given individual will respond to high altitude.” 

It’s worth noting that this adaptation doesn’t happen overnight. According to Tollefson, “Most research supports an athlete spending three to four weeks at altitude for maximal adaptations.” Adsit-Morris adds that “the research has shown that there are benefits from short stints (one to two days) of altitude training as well.”

Henderson goes a bit deeper, explaining that in seven to 10 days the body will make changes that facilitate the offloading of oxygen from existing red cells. Later the actual number of those red cells carrying oxygen will increase.  “It takes three to four weeks of continuous exposure to altitude to achieve significant increases in red cell mass in responders” he says. 

Built-in Benefits

Photo: Mitchell Quiring

Henderson also points out that there is an actual benefit to all that wheezing and gasping I was doing on Wolf Creek Pass — or there would be if I had stayed there long enough.  “The respiratory muscles are just like other muscles in the body, and an increase in respiratory muscle endurance may be one of the factors that facilitates improvement in endurance performance at sea level after training at altitude.” In other words, your lungs get stronger.  

That being said, you actually de-train when you go to altitude because you can’t go as hard as you normally do. Sure, you might hit higher heart rates, but you’ll be doing less work because you’re moving less oxygen. Only once your body has had time to adapt to the altitude do you see the benefits.

There’s also what Adsit-Morris calls ‘the training camp effect.’ “Athletes generally tend to be able to focus and perform better during training camps,” she observes. “Living with other athletes, away from normal everyday stresses and distractions, athletes are able to focus all their energy and time on training. It is also easier to train with a group than alone. Having other athletes around keeps everyone accountable; we are more likely to do all the ‘little things’ we normally skip when we are busy, like stretching, core work and eating healthier.” The lack of, say, a thriving club scene in Mammoth probably doesn’t hurt either. 

Of course, some populations have been living at altitude for generations; these so-called “altitude natives” may enjoy athletic advantages thanks to one of the fastest natural selection adaptations ever seen. Not only do these altitude natives have more red cells, each red cell also carries more oxygen. 

A recent study of Tibetan villagers who live their lives at around 15,000 feet revealed that they have 10 oxygen-processing genes not commonly found in lowland populations. And Egan Bernal, the winner of the 2019 Tour de France, hails from Bogotá, the 8,660-foot capital of Colombia. 

The Live High, Train Low Secret

Photo: Miles Weaver

To overcome the issues around training at altitude, pros swear by the “live high, train low” (LHTL) approach. Using LHTL, athletes will sleep and live at altitude while training closer to sea level, which allows their performance to be uninhibited. 

“The athletes can run faster and farther at a lower altitude, thus producing greater muscular power, then quickly return back to the upper elevations to continue creating more red blood cells,” says Kastor, making sure to emphasize that “red blood cell production, along with all other training adaptations, takes place while the athlete is asleep.” 

Unless you are a very serious athlete, you’re probably not going to uproot your whole life to move to Mammoth or Boulder and make your lungs stronger. What if, instead of you going to the mountain, the mountain could come to you? Turns out it can.

It is also possible that high-oxygen environments could increase recovery speed. Henderson cites evidence of patients recovering more quickly from burns; he believes athletes could see concurrent benefits. 

Accordingly, the Kastor-led Mammoth Track Club has been using LHTL since 2001, when its runners began training 4,000 feet lower in Bishop, California. Meanwhile, at Henderson’s Apex Endurance in Boulder, Colorado, things get high tech: “When we have individuals preparing for competition at sea level, we tend to introduce weekly hyperoxic high-intensity training sessions [using a mask or altitude-controlled room to simulate sea level air] in order to replicate the output that can be maintained at sea level.” 

Altitude Simulation, No Mountain Required

At this point, the benefits of training — or at least living — at altitude are pretty clear. But unless you are a very serious athlete, you’re probably not going to uproot your whole life to move to Mammoth or Boulder and make your lungs stronger. What if, instead of you going to the mountain, the mountain could come to you? Turns out it can. 

Olympic cyclist and former world champion Shaun Wallace now runs Altitude Control Technologies, an industry leader in the field of “altitude simulation.” I spoke with the Live High, Train Low pioneer about how altitude is meeting athletes where they live. 

The summer after that race in Colorado, I spent weeks sleeping in a sweaty plastic tent. It wasn’t because I was not making enough money racing bikes to pay rent, although that was also true, but because I was trying to “sleep high” while living in San Diego. But Wallace says that merely sleeping at altitude is not enough. There might be an initial boost, but his experience has been that athletes begin to see more adaption with more time at altitude. 

“Once we learned to stop pushing the altitude higher and higher, and just increased the time instead, we got much better results,” he explains. This is pretty challenging with traditional altitude tents. I can tell you that eight hours in that sweatbox was bad enough, and had Tinder been around back then, I’d make for an instant “swipe left” if I added the mountain air boudoir experience to my profile. What Wallace’s company offers instead is rooms and whole homes that are altitude controlled. 

Although he can’t reveal his client’s names, it’s well known that the Nike Oregon project uses an altitude house for its runners, and ACT’s website proudly displays the logos of not only Nike but also the Green Bay Packers, Philadelphia Flyers, three NBA teams and legendary soccer club Real Madrid.

On a related note, altitude adaptation is thought to give such a huge advantage to home teams in high-altitude cities that FIFA once banned games above 8,200 feet. And Japan’s Institute of Sports Sciences recently built a 73-room altitude hotel in the hope of giving its athletes an edge at the (sea level) Tokyo games. 

Many athletes report not only increased performance at altitude, but also better and more restful sleep. Wallace confides that, somewhere between 4,000 and 8,000 feet, many people seem to find an altitude at which they recover better than they do at sea level. 

The Most Effective Hack: Maximizing an Altitude Window

Of course, converting your house isn’t cheap. You can get that same “breathing through a straw” altitude feeling by, well, breathing through a straw. Indeed, there are a lot of inspiratory muscle trainers on the market that claim to offer the benefits of altitude at a much lower cost by simply restricting your ability to breathe, but none of the experts we spoke to supported their use as a substitute for altitude. 

“They might have some benefit, but it’s not the same as altitude,” says Wallace, going on to explain that these devices make it harder to breathe by restricting your airway, rather than by creating a hypobaric atmosphere. This might sound the same, but the former works by strengthening your lungs and the latter by changing your blood. Henderson points out studies show that some athletes, especially less well-trained ones, might benefit from this kind of respiratory training, but it won’t make as much of a change as time at altitude. 

There is also plenty of evidence that repeated exposure to altitude helps, so if you are planning on climbing a 14er or racing the Leadville Trail 100 this year, even a few weekends in the high country is much better than nothing.

Still, certain gear can help you adapt to altitude and use it to your advantage. Wallace says that a good pulse oximeter is key. This little device measures the blood oxygen saturation (or SpO2) by estimating the amount of oxygen bound to hemoglobin in your blood. It does this by sending a beam of light through your finger and noting how much of the light is absorbed by red blood cells. Normal ranges are 94 to 100, and below that it’s not a good idea to train. Measuring every day would allow you to see your norm, Wallace says, and how you are adapting to training at altitude. The Garmin Forerunner 945 does exactly that, logging your SpO2 all day and tracking your body changing as you take that two-week hiking trip to Colorado. 

There is also plenty of evidence that repeated exposure to altitude helps, so if you are planning on climbing a 14er or racing the Leadville Trail 100 this year, even a few weekends in the high country is much better than nothing. Mammoth is a great spot for a DIY camp — it hosts thousands of athletes each year, and is well set up with running tracks, trails and a lift-assisted mountain bike park for those days when you’d rather not tax your lungs by riding up hill in order to send it down. 

If you want something more structured, Leadville hosts training camps in the highest incorporated city in North America. You can start at 10,152 feet in town and it’s uphill in just about every direction. I have been there, and it is indeed, ahem, breathtaking. Leadville also happens to host the most prestigious mountain bike, burro racing, and trail running events in the US, making it an endurance mecca despite being literally the hardest place in the country to work out. 

Photo: Alex Chiu

Adsit-Morris also has some tips for would-be altitude training athletes: “I would suggest getting bloodwork done before you go to altitude to make sure your iron levels are good, especially for women. Sometimes my coach will even have us “pre-load” with iron supplements before we begin our training camp. I also found that going into training with a good core routine was really essential. The first time I went to altitude, I had a lot of diaphragm cramping which I think was due to a lack of a strong core. Finally, have fun and enjoy the process!”

If your goals involve altitude, don’t despair. The real function of endurance events is to find your limit. Even at single digit speeds grinding up Wolf Creek pass a decade ago, I found mine. If you’ve read this far, you are far more informed than I was back then and hopefully not considering abandoning your sport altogether. If you are, just wait until you get home and feel like you’re running on premium fuel again, and maybe you’ll reconsider. Three weeks after we scaled Wolf Creek pass, I won a nice, flat, sea level race in Coastal California. 

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James Stout

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