As a UESCA-certified running coach, I work with runners of all levels, from competitive and elite runners to beginners who are just starting their running journey with some jogging and walk/run intervals.
While the level of runners I coach clearly spans the gamut, almost every runner is interested in becoming faster or “better“ as a runner.
Running at altitude has long been a practice of elite runners and Olympic athletes in endurance sports to help boost endurance performance.
High altitude training can provide a myriad of cardiovascular and physiological adaptations that can benefit aerobic performance and ultimately translate to a higher VO2 max and better aerobic efficiency at lower altitudes.
This is why we see high-altitude training camps in Boulder, Colorado, Flagstaff, Arizona, and some higher-elevation areas in Africa, Europe, and other parts of the United States.
But, is high altitude training only for elite runners or Olympic runners? Can everyday runners benefit from training at altitude? Can you simulate the benefits of training at a high altitude if you live at sea level or a lower altitude?
In this guide, we will discuss what constitutes high altitude training, its cardiovascular benefits, why we experience physiological adaptations when running at altitude vs sea level, and tips for how to train at a high elevation.
We will cover:
Let’s dive in!
Is it more difficult to run at higher altitudes?
If you have ever been to the Swiss Alps, Flagstaff, Arizona, Mexico City, or any other high elevation area, you might be familiar with the phenomenon of feeling relatively breathless even at a slow walking pace.
In fact, you don’t have to be in the Himalayan mountain range, scaling the Matterhorn, or crossing off one of the 14,000-foot mountains in Colorado to experience the effects of higher elevation.
Particularly if you live at sea level or close to it, even a “moderate elevation“ such as 6,000 feet above sea level can feel notably different from a respiratory and cardiovascular standpoint.
That said, in most cases, runners and other endurance athletes who practice high altitude training go to locations that are at least 7,000 to 8,000 feet above sea level and often up to 10,000 to 12,000 feet above sea level.
Sports science technology has also allowed endurance athletes to take advantage of the benefits of altitude training with the “live high, train low“ approach by using altitude training tents.
Some runners may also practice the reverse: “live low, train high, “ in which they might use an altitude training mask for training runs to simulate the limited oxygen availability of high altitude training conditions.
What Is the Purpose of High Altitude Training for Runners?
The primary purpose of high altitude training for endurance athletes is that spending time training at higher elevations causes physiological adaptations to the cardiovascular system.
This is because the amount of available oxygen in the air decreases the higher you get relative to sea level.
A common misconception is that there is less oxygen in the air at higher elevations.
However, all atmospheric air contains 21% oxygen, regardless of whether you are at sea level or 60,00 feet above sea level, 10,000 feet above sea level, or even 15,000 feet above sea level.1Physiology. (n.d.). Institute for Altitude Medicine. Retrieved January 15, 2024, from https://www.highaltitudedoctor.org/physiology#:~:text=The%20percent%20of%20oxygen%20is
That said, the available oxygen that you can breathe in with each breath at altitude decreases significantly because there is less air pressure the higher you get above sea level.
Essentially, while the amount of oxygen in the air remains the same at any elevation—21%—this 21% results in less oxygen when there is less air pressure (as there is the higher the altitude).
At sea level, the barometric pressure is 760 mmHg, and at 10,000 ft, the barometric pressure is only 534 mmHg.
This lower air pressure results in the equivalent of breathing air with only 15% oxygen at sea level, instead of 21%, which feels like 29% less oxygen in the air at 10,000 ft of elevation vs sea level.
Air pressure continues to drop as elevation increases.
Thus, you have to breathe deeper and faster at high altitudes to take in the same net amount of oxygen that you can breathe in at sea level.
After you’ve adapted, the effort to breathe will feel comparatively easy when you go back to running and racing at sea level.
This will allow you to run faster without being breathless (pushing your anaerobic threshold to faster paces), improving performance.
How hard is it to run at altitude?
As explained, one of the main challenges of training at higher elevations versus lower altitudes or sea level is that much less oxygen is available at higher elevations.
Ultimately, this lack of oxygen induces the physiological changes seen after acclimating to high altitude training.
However, before your body has adapted to having less oxygen at higher altitudes, you can experience the myriad of side effects of higher elevations.
When there is less oxygen available in the atmosphere, your heart and lungs must work much harder to extract oxygen from the air and then deliver that oxygen to your body.
For this reason, you can experience a rapid heart rate, difficulty breathing or a faster breathing rate, and other cardiovascular challenges when you first experience higher elevations before acclimating.
This is why it is always recommended to slow down your running pace or physical exertion level for your first several high altitude runs.
Once you seem to be in the clear of dealing with acute mountain sickness or altitude sickness, you can start trying to pick up your pace and follow your normal training plan as your body adapts to the effects of altitude.
Still, keep in mind that the acclimatization process for high altitude training can take several weeks, so if you are struggling to hit your normal training paces as dictated on your training plan, know that it is OK to slow down and give your body time to adapt to high altitude fully.
As a result, many running coaches recommend training by heart rate when you first start high-altitude running rather than training by pace.
It is completely normal to experience an elevated heart rate when you first start running at altitude vs sea level, so you can use your heart rate to help guide your physiological exertion level and your body’s tolerance to the lower amount of oxygen and changes in air pressure at higher elevations.
What are the benefits of Running At Altitude?
So, how exactly does subjecting your body to less oxygen improve performance?
Here are some of the primary physiological benefits of high altitude training for runners:
- Increasing your aerobic capacity (VO2 max) and aerobic endurance at sea level because oxygen delivery and extraction improve as the body works harder to make do with less oxygen coming in.2Levine, B. D., & Stray-Gundersen, J. (1997). “Living high-training low”: Effect of moderate-altitude acclimatization with low-altitude training on performance. Journal of Applied Physiology, 83(1), 102–112. https://doi.org/10.1152/jappl.1997.83.1.102
- Increasing the production of erythropoietin,3Park, H., Hwang, H., Park, J., Lee, S., & Lim, K. (2016). The effects of altitude/hypoxic training on oxygen delivery capacity of the blood and aerobic exercise capacity in elite athletes – a metaanalysis. Journal of Exercise Nutrition & Biochemistry, 20(1), 15–22. https://doi.org/10.20463/jenb.2016.03.20.1.3 the protein that stimulates the production of red blood cells. Red blood cells carry oxygen, so the more red blood cells you have, the more oxygen your muscles will receive while you run. Because less oxygen is inhaled per breath, your body has to become more efficient at delivering the limited oxygen molecules to your muscles.4Chawla, S., & Saxena, S. (2014). Physiology of high-altitude acclimatization. Resonance, 19(6), 538–548. https://doi.org/10.1007/s12045-014-0057-3
- Increasing your lactate threshold because the muscles become better at buffering the acidic metabolic byproducts of glycolysis (anaerobic metabolism). A higher lactate threshold allows you to run faster at a “steady state” or “comfortably hard” effort before feeling fatigued.5Bahenský, P., Bunc, V., Tlustý, P., & Grosicki, G. J. (2020). Effect of an Eleven-Day Altitude Training Program on Aerobic and Anaerobic Performance in Adolescent Runners. Medicina, 56(4), 184. https://doi.org/10.3390/medicina56040184
- Increasing metabolic rate and energy expenditure by 2-3 times relative to the calories burned running at sea level.6Michalczyk, M., Czuba, M., Zydek, G., Zając, A., & Langfort, J. (2016). Dietary Recommendations for Cyclists during Altitude Training. Nutrients, 8(6), 377. https://doi.org/10.3390/nu8060377
Are there any potential downsides to high altitude training?
Of course, there are drawbacks or risks associated with running at altitude, including the following:
- Harder to maintain the same intensity or running pace
- Dehydration7Michalczyk, M., Czuba, M., Zydek, G., Zając, A., & Langfort, J. (2016). Dietary Recommendations for Cyclists during Altitude Training. Nutrients, 8(6), 377. https://doi.org/10.3390/nu8060377
- Altitude sickness
- Slower recovery
- The costs associated with traveling to altitude or getting an altitude training tent
A sudden increase in the elevation you’re spending time in can result in altitude sickness.8Hartman-Ksycińska, A., Kluz-Zawadzka, J., & Lewandowski, B. (2016). High altitude illness. Przeglad Epidemiologiczny, 70(3), 490–499. https://pubmed.ncbi.nlm.nih.gov/27888818/
Altitude sickness is the most common risk of jumping up to a higher elevation when you live at sea level or a low altitude.
In fact, altitude sickness can occur even if you are not running at altitude or performing any vigorous physical activity for that matter.
For example, people who live at sea level and then travel to areas like Boulder or Flagstaff, or popular tourist destinations at higher elevations such as Machu Picchu in Peru often experience symptoms of altitude sickness—or even acute mountain sickness shortly after getting off the plane.
So, what is altitude sickness or acute mountain sickness, and what are the altitude sickness symptoms to be wary of before you can feel more confident in your body‘s ability to handle high-altitude runs?
Symptoms can be mild to debilitating and include headache, nausea, appetite loss, fatigue, rapid heart rate, dizziness, difficulty breathing, vomiting, pulmonary edema, and cerebral edema and may last 2-4 days.
How to Do High Altitude Training
If you have the opportunity to spend a significant amount of time at altitude, you can take advantage of the benefits of high altitude training.
However, for most everyday runners, this is not financially or logistically feasible.
Studies show9Park, H.-Y., Park, W., & Lim, K. (2019). Living High-Training Low for 21 Days Enhances Exercise Economy, Hemodynamic Function, and Exercise Performance of Competitive Runners. Journal of Sports Science & Medicine, 18(3), 427–437. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6683611/ the LHTL approach to high altitude training can provide many of the same benefits of living and training at elevation.10Wilhite, D. P., Mickleborough, T. D., Laymon, A. S., & Chapman, R. F. (2012). Increases in VO2max with “live high–train low” altitude training: role of ventilatory acclimatization. European Journal of Applied Physiology, 113(2), 419–426. https://doi.org/10.1007/s00421-012-2443-4
This would involve getting a high altitude training tent to simulate the lower oxygen availability at high elevations. You sleep in the altitude training tent and then do all of your running and regular day life normally.
If you do have the opportunity to try high altitude training, there are a few precautions that can make the process easier.
Here are my top tips for maximizing the benefits and minimizing the risks and downsides of high altitude training for runners:
- Be patient. It takes time to go through the acclimatization process—usually at least 5 days for your body to start adapting and producing more erythropoietin.
- Realize that benefits level off. Most experts say that the hematological adaptations start leveling off after about 25 to 30 days at altitude, so if you want to maximize your spike in oxygen-carrying capacity while not disrupting your life too long, a high altitude training stint of 1 to 4 weeks is ideal for most runners.
- Take iron supplements before you head off to a high altitude training camp to help bolster your ferritin levels and maximize your hemoglobin concentration. But note that you should get a blood test first because excess iron can be toxic, particularly for males. Olympic runners undergoing high altitude training are advised to take 60-65 mg of elemental twice a day with vitamin C to increase absorption.
- Focus on sleep and recovery.
- Run at a slower pace or ease your effort in workouts until you feel like you have adapted better to less oxygen.
- Consume more calories and more carbs specifically so that your body has enough fuel for a higher heart rate and greater reliance on carbs for energy, even at lower intensities.
- Hydration is key. Drink more water because elevation exacerbates dehydration and staying well hydrated can help offset the side effects of high altitude.11Hartman-Ksycińska, A., Kluz-Zawadzka, J., & Lewandowski, B. (2016). High altitude illness. Przeglad Epidemiologiczny, 70(3), 490–499. https://pubmed.ncbi.nlm.nih.gov/27888818/ Research demonstrates that respiratory water loss at high altitudes may be increased to 1900 mL per day in men and 850 mL per day in women, and urinary water loss may increase up to 500 mL per day as well.12Michalczyk, M., Czuba, M., Zydek, G., Zając, A., & Langfort, J. (2016). Dietary Recommendations for Cyclists during Altitude Training. Nutrients, 8(6), 377. https://doi.org/10.3390/nu8060377
So, whether you want to travel to an area of high elevation, or try and simulate the effects of altitude with the “live high train low approach“, hopefully, you’ve picked up a few good tips and have a better understanding of why endurance athlete‘s and running coaches often try to employ practices that will garner the beneficial effects of altitude training.
For more information on the acclimatization process, check out this next article:
Hi Mia. Thanks for the article. Would you expect the inverse of that equation if training at altitude and going to sea level? Gut says less effective. Been running in Boulder and heading to sea level to race next month and trying to figure out a pace.
Thanks!
Grant