10 Rules for Altitude Training

At the 1996 Olympic Games in Atlanta, American distance runners earned a total of zero medals in front of their home fans. Two decades later, in Rio, they picked up seven medals in events between 800 meters and the marathon. What changed?

There are plenty of theories, including changes in training philosophy, the rise of sponsored all-star training groups, and the dissemination of knowledge on the Internet. But a new paper in the International Journal of Sports Physiology and Performance argues that sports science also played a role. Essentially no American runners used altitude training to prepare for Atlanta. Then, in 1997, Ben Levine and James Stray-Gundersen published a paper introducing the concept of “live high, train low” (LHTL) altitude training. By 2016, every single one of the American medalists was using this approach.

LHTL involves spending as much time as possible in thin air (either in the mountains or in simulated altitude chambers) in order to trigger the production of hemoglobin-rich red blood cells to ferry oxygen to the muscles, but also descending regularly to lower altitudes for key training sessions in order to be able to run fast in oxygen-rich air. The new paper is by a group led by Olivier Girard of the University of Western Australia. Levine is one of the co-authors, along with fellow altitude training pioneers Robert Chapman and Randy Wilber. It’s dedicated to Stray-Gundersen, who passed away last fall. To toast the success of a quarter-century of LHTL training, they’ve distilled ten key lessons based on a mix of research and practical experience working with elite athletes.

Before I get to those ten lessons, I should note that not everyone is as gung-ho about LHTL as its originators. Back in 2020, I wrote an article summing up the skeptical view about why altitude training might sound good in theory and not work in practice. There are also long-running debates about why some people seem to respond to altitude training and others don’t. And indeed, studies like this one, published last month, keep appearing: four weeks of LHTL training boosted hemoglobin levels in elite Finnish cross-country skiers, but didn’t improve performance.

One thing everyone agrees on is that simply buying a plane ticket or an altitude tent doesn’t guarantee that you’ll get faster. So with that in mind, here’s my take on Girard et al.’s ten lessons.

1. The dose matters

The altitude sweet spot is relatively narrow, between about 5,900 and 9,800 feet (1,800 to 3,000 meters) above sea level. Go higher, and you’ll have trouble sleeping and recovering from workouts; stay lower, and you won’t trigger significant adaptations. You need to accumulate at least 200, and preferably more than 300 hours—a couple of weeks, basically—at altitude to see benefits.

2. No one really knows who will respond and who won’t

As I discussed in this previous article, there are lots of theories about how to identify non-responders, but no definitive answers. Ever optimistic, the authors suggest that some people may be slow responders rather than non-responders. The key practical point is that (if you happen to have a sports science team at your disposal) you should measure your response so you know whether altitude training is helping you or not.

3. Good iron stores are a prerequisite

To make red blood cells, you need iron. That means there’s no point in heading to altitude if your iron levels are low. The ferritin thresholds the authors suggest are at least 20 micrograms per liter for women, and at least 30 for men. Some experts suggest that even those who exceed those thresholds should take iron supplements while they’re at altitude.

4. Adjust your training

Living at altitude is a stress on your body, so you can’t just add that stress to your usual training load without consequences. That typically means dialing back training before heading to altitude, and reducing training volume by as much as 25 percent in your first week at altitude.

5. Getting sick or overtrained will negate the benefits

In addition to the added training stress, it’s harder to sleep at altitude, and dehydration happens quickly in the dry air. As a result, it’s important to pay close attention to how you’re recovering, how well you’re sleeping, and how hard the training feels. When in doubt, back off.

6. Timing is everything

On the question of when to plan an altitude block relative to your goal race, Girard and his colleagues write, “every practitioner has an opinion.” There’s a general sense that racing in the first week after coming down from altitude is good, the second week is bad as your body readapts to sea level, and then you get another sweet spot from the third to fifth week. But no one is really sure, and there may be lots of individual variation. One point of consensus: you probably need a few days of easy training, either in the final days of the altitude block or immediately after, to recover from the added stress of altitude training.

7. Real and simulated altitude both work

The overall body of research suggests that you can get similar boosts from using an altitude tent or chamber as from going to the mountains. It’s not easy, though. You need to spend at least 12 to 14 hours a day in the altitude room to trigger meaningful adaptations, which may drive you nuts or at least force you to be way more sedentary than you’d like.

8. There’s no gold medal for best blood test

This is the point that altitude training skeptics harp on. Altitude training reliably boosts red blood cell levels (on average, at least) and triggers other physiological adaptations. But that doesn’t always translate into better race performances. That gap may be a result of not giving yourself a chance to recover from the training fatigue accumulated during the altitude camp. Or there may be other explanations, as yet undiscovered.

9. It works for team sports and racket sports too

Traditionally, altitude training was for endurance athletes. But more recently, other sports like tennis and soccer have started using it, and there’s evidence that it helps with repeated sprint performance. Interestingly, since these athletes usually start with lower hemoglobin levels than endurance athletes, they may even get benefits from shorter camps of less than two weeks.

10. Heat and high-altitude sprints may also help

There are various add-ons that might make LHTL training even more effective. Instead of doing all your intense training at low altitude, all-out sprints at high altitude might be effective for repeated-sprint performance in team-sport athletes. A bout of heat training might enhance your plasma volume (the part of your blood that doesn’t include red blood cells) before heading to altitude (where you’ll produce more red blood cells), possibly producing a bigger overall effect. There are a lot of “mights” in there, but these are areas of active research.

What you make of all these “lessons” probably depends on whether you’re a glass-half-empty or a glass-half-full person. To Girard and his colleagues, the LHTL approach to altitude training has been a smashing success, as evidenced by all those Olympic medals, and they’re sharing all these nuances to help other people do it right. To skeptics, all these caveats are precisely why so many subjects in so many studies don’t get any faster than those in the control group doing sea-level training camps. On balance, the safest conclusion is that there’s no free lunch. Getting altitude training right takes a lot of hard work, a lot of careful planning, and a little luck—which, for endurance athletes, is just the way we like it.

For more Sweat Science, join me on Twitter and Facebook, sign up for the email newsletter, and check out my book Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance.