Everyone knows that the world’s best runners hail disproportionately from East Africa. But not all Kenyans and Ethiopian excel at running. A vast majority of the top talents from these two countries live and train in small regions in the Rift Valley, elevation 7,000 feet.

This is no coincidence. Science has shown that distance runners naturally get fitter when they spend time at altitude. And you don’t have to be an elite runner to benefit. At Dream Run Camp, also located at 7,000 feet in easy-to-reach Flagstaff, Arizona, everyday runners achieve major breakthroughs in performance after spending time here. Is high-altitude training the key to your next breakthrough? Let’s look at the science.

Out of Thin Air

The air at 7,000 feet is very different from the air at sea level. When people describe the air at high elevations as “thin,” what they mean is that the barometric pressure is lower. In places like Flagstaff and the Rift Valley, the barometric pressure is about 11.3 pounds per square inch, compared to 14.7 PSI at sea level. As a result, your lungs absorb less oxygen with each breath, and because of this, your entire cardiorespiratory system has to work harder to ensure you get enough oxygen. You’ll see this if you track your resting heart rate. If it’s 50 beats per minute at sea level, for example, it’s likely to be closer to
55 BPM at 7,000 feet.

Your body perceives the relative lack of oxygen in the mountains as a stressor, almost like continuous gentle exercise. Your body is smart, though, so it doesn’t just work harder to deliver oxygen to your tissues when you’re in this environment; it adapts to become better at delivering oxygen. Within a few days of arriving at altitude your blood volume will decrease, which increases the concentration of oxygen-carrying red cells in your blood, allowing for more efficient oxygen delivery. Over the next few weeks, your red blood cell concentration will increase further as your body produces new red blood
cells at an accelerated rate.

Training at sea level also increases the oxygen-carrying capacity of the blood, but not nearly as much. A 2020 study found that 11-days of altitude training increased VO 2 max (a measure of the body’s ability to consume oxygen during exercise) by an average of 13.6 percent in teenage runners, which translated to a 9.6 percent increase in running performance.

It’s worth noting that 6,000 – 8,000 feet is considered optimal for altitude training. At lower elevations, the body isn’t stressed as much, so it doesn’t adapt as much. At higher elevations, the body is too stressed and both training and recovery are negatively impacted.

Prepare for Takeoff

The benefits of altitude training come at a cost. Adapting to life at 7,000 feet can be challenging, and it takes time. In your first few days in the mountain you’re likely to experience one or more of the following effects: increased thirst, dehydration, changes in appetite and sleep, dry skin, fatigue, headache, and shortness of breath. You can mitigate some of these effects by coming prepared. At Dream Run Camp, we encourage new arrivals to drink plenty of water, moisturize their skin, sleep with a humidifier, and take it easy.

Another way to prepare for altitude training is by getting your iron level checked and increasing your iron intake if it’s low or borderline. That’s because iron is a key ingredient in red blood cells, therefore your body needs more iron when you’re spending time in thin air. And if you spend more than a few weeks at 7,000 feet, you should recheck your iron to make sure you’re keeping up with your body’s needs. Low iron is the number-one reason for disappointing experiences with altitude training, and it’s
preventable.

For motivated runners, taking it easy is especially important. It’s very common to feel sluggish initially when exercising at high altitude. You won’t do yourself any favors by forcing things. When I first came to Flagstaff in 2017, my coach instructed me to rest on day one and run short and easy on days two and three. Accustomed to doing much more, I felt restless, but when I started training harder on day four, I’d gotten past the awkward early phase of the adjustment to high elevation and was ready to go. I now tell Dream Runners who come here from low-lying locations that the less they do in their first few days, the more they’ll be able to do later, and it’s true. The few who struggle up here are the ones who try to go hard from the beginning. It takes about two weeks to fully acclimate to life at 7,000 feet, though there’s quite a bit of individual variation. You just need to be patient and trust the process. Everyone adjusts eventually.

Speaking of Adjustment

Another important thing to keep in mind is that, although training at altitude will make you faster at lower elevations, you will always be slower at high elevations, even after you acclimate. The fastest mile ever run at 7,000 feet is 3:57.33, while the fastest mile ever run at sea level is 3:43.13 seconds. No matter how fit you are, there’s just not enough oxygen up here to support the same level of performance. When college runners race at Flagstaff’s Lumberjack Stadium, their times are adjusted to sea-level equivalents for championship qualification purposes. You need to do something similar with your training paces when you come here. I use the VDOT Running Calculator for these conversions. If your easy run pace at home is 10 minutes per mile, for example, your Flagstaff-adjusted pace is 10:33 per mile. Yes, it’s slower, but it’s equivalent in terms of how hard your body is working. Don’t fight it; the many professional runners who come here from all over the world to train slow down, and you should too.

If you train by heart rate, it’s a little different. In the first few days of acclimation, your heart rate during running will be inflated and not a good guide to your true effort level. By day five or so it will have settled down, and thereafter your heart rate at different intensities should remain close to your heart rate at the same intensities back home, though the associated paces will of course be slower.

Final Thoughts

You might be wondering how you can possibly get faster by training slower than you’re accustomed to. It’s a good question, and the answer is that you don’t. Runners get fitter and faster by living at high elevation, not by training there. It’s the 23 hours of the day when you’re not running that change your body in favorable ways. Exercising at altitude in itself is no better than exercising at sea level, where you’ll always be faster. To get the best of both worlds, some runners engage in a practice known as live high, train low, basing themselves in the mountains and coming down periodically to train faster. One of the reasons Flagstaff is such a mecca for runners is that it’s relatively easy to get to lower elevations for key workouts. Camp Verde sits 3,900 feet lower than Flagstaff and less than an hour away, and I take runners there often. For the most part, though, we stay put, enjoying the limitless running venues Flagstaff offers. Runners would come here even if it weren’t at 7,000 feet, just to experience its forest-covered trails and roads and stunning mountain views.

Which brings me to my final thought: Don’t make too much of the altitude factor. There’s something to be said for breaking away from home routines and coming to a place like Dream Run Camp for focused training, expert coaching, ample recovery, and connecting with likeminded runners that goes far beyond red blood cells.