The Everything Guide to Running at Altitude

Your race is above the clouds but your home is decidedly below them. What to do? Athletes, coaches, and scientists share their tips and debunk the myths.

Scan the list of home states on the Hardrock or Leadville results page, and they’ll read something like: “Colorado. Utah. California. Colorado. Colorado. Colorado,” all the way down through the top 50. That can seem a little unfair if you’re a lowly flatlander hauling it up to Silverton from sea level.

But it’s not as big of a disadvantage as you might think. “The biggest misconception is that you can’t be successful,” says Jason Koop, who’s coached New Yorkers for some of the hardest races on the planet with training runs in Central Park. Among his success stories: flatlander Kaci Lickteig who finished this year’s famed Western States 100-miler in 14th place.

Train right, with the right information, and you’ll find altitude is easily overcome.

Arrive Fashionably Early

At sea level, the air is thick, densely compacted by the weight of the atmosphere above it. As you climb away from the coast, this effect decreases, so while the percentage of oxygen in the air remains the same (about 21 percent), those molecules are spread more sparsely. Every breath is thinner, more composed of empty space. By the time you reach 12,000 feet, you’re left with just 60 percent of the oxygen that was available to you when you started. That takes some time to get used to. Two to three weeks, to be exact.

That’s a lot of time for someone with a day job and a demanding work schedule. Take Lickteig, for example. She works full-time as a physical therapist in Omaha, Nebraska (elevation: 1,090 feet), and saves her vacation days for race days. That doesn’t leave much time for acclimatization, but she’s proof that the right training is enough to overcome that gap.

On the other end of the scale, some coaches advise arriving as close to the starting gun as possible. That’s because altitude sickness, or Acute Mountain Sickness (AMS), typically starts within 24 hours at elevation. However, symptoms can begin as soon as six hours after arrival, which puts onset right in the middle of the race.

Your best bet? Spend a little time at altitude long before the race starts to figure out how your body adapts. For many people, symptoms of AMS vanish within three to five days, and by that time, red blood cell production and breathing efficiency will have had time to build past what they were at 24 hours. In fact, most of those physiological and metabolic changes occur within the first week, according to Dr. Andrew Subudhi, PhD, with the Altitude Research Center at the University of Colorado. Improvements persist into second and third weeks, but at a less dramatic rate, he says.

That means arriving just a few days before your race should provide enough buffer for most people to get over that first acclimatization hurdle.

Make the Most of What You’ve Got

Altitude isn’t the only consideration for a sea level athlete with eyes on a mountain race. On-course elevation gain is a major consideration and can be a challenge for those from the flatlands. Ask 10-time Hardrock 100 finisher Billy Simpson to describe the terrain of his hometown, Memphis, Tennessee (elevation: 337 feet), and he’ll give you two words: “Dead flat.”

“Find the hilliest little trail you can, and treat it like a job.”

Not optimal training for a race that boasts over 33,000 feet of vertical gain. How to cope? “Find the hilliest little trail you can, and treat it like a job,” says Simpson. For him, that means a three-mile circuit on the Red Loop Trail in Meeman-Shelby Forest State Park. “I get on that thing, and I work,” he says. He’s even coordinated races on the same undulating patch of trail to boost motivation for timed runs.

Lickteig’s strategy is similar. Western States 2014 was her first true mountain race. She’d run 100s before, and as such, launched into the run with more confidence than she perhaps should have. The 1,200-foot descents weren’t something she’d prepared herself for. “Forty miles into the race, I had blown my quads,” she said. “I finished, but those last 60 miles were brutal. It really humbled me.”

She resolved to focus on elevation training and return to Western States better prepared. But the biggest hills she has in Omaha are a couple hundred feet each, scattered throughout the Hitchcock Nature Center trails (Westridge and the Legacy Loop pack a particular punch.), and she can only get to them on the weekends. “If I’m there for four hours, I get about get about five thousand to six thousand feet of cumulative elevation gain,” she says. Back-to-back days on those hills have been crucial for strengthening her quads and hip flexors for successive Western States.

Mileage: Think Quality Over Quantity

During the week Lickteig, must make do without hills. She could run up stairwells or do repeats in parking garages. But she doesn’t. Nor does she do squats or go for hikes in a weighted vest.

“Ultrarunners are pretty notorious for contriving their training and coming up with all these crazy ways to cope with the demands of an ultramarathon,” says Koop. “But those types of training modalities don’t have a lot of efficacy behind them.”

Instead, Lidecki does what gets her the most bang for her buck: running hard. Because she lives at sea level with hills one-tenth the size of an ideal training climb, Lickteig is careful to maximize her time and squeeze every last drop of benefit from each workout.

She schedules high-intensity interval training (10-minute repeats at a 6-minute mile pace) at the beginning of the year, 90- to-100-mile weeks of tempo and steady state runs mid-season, and endurance training at an “easy” 7:30+ pace as the races approach. Steady state workouts, running just below lactate threshold, get particular attention because that’s the intensity she can keep up for most of the climbs at Western States.

This was the final ascent to achieve 6,000ft+ of elevation today. I pushed myself out of my comfort zone. They say you need to work on your weaknesses in order to get better. I am a weak climber and will almost always choose the ‘runnable’ route versus the climbing route. However, that was not the case today. @jasonkoop wanted me to go after as much vert that I could get. That is in fact exactly what I did. It was not easy by no means and I had to talk myself out of stopping several times. I dug deep and found inspiration from those who love vert, and it helped! So thank you all for being my inspiration when the going gets tough! #niketrail #ctsathlete #carbopro #getvert #ws100 #trails #running #bestrongerthanyouthinkyouare

A photo posted by Kaci Lickteig (@ultrarunnerkc) on

“It’s not about the quantity of miles, it’s about quality,” says Simpson, who focuses on putting in hard 20-mile runs rather than long, slow endurance days. For the 62-year-old, that means progression runs, starting at a 9-minute pace and ending at 7:30. When he was a younger man, those numbers were 7 and 5:15. “If you live in the flatlands, the intensity has got to be turned up. You’ve got to be prepared for the stress of altitude, and you do that by getting strong.”

At the end of the day, the athletes who do best at altitude are the fittest, so “the goal is to get your cardiovascular engine as tuned as possible,” Koop says. “Acclimatization is just a supplement to your fitness, not a replacement.”

Sleep High, Train Low?

Some athletes run with airflow-restricting masks that supposedly simulates altitude. Athletes with a tight budget (and a keen eye for fashion) will achieve the same effect by working out with a snorkel. “That’s a load of bologna,” Koop says. “Those measures are counterproductive because they just mean you can’t run as fast.”

The training maxim “Train low, sleep high,” means go where the oxygen is to work out as hard as possible, then seek out thinner air so your body produces extra red blood cells while you sleep. You can achieve the difference by driving down from your mountain home for your daily run if you live at altitude or sleeping in an altitude tent, which scrubs oxygen from the surrounding air, if you live at sea level. The latter is often to more effective for sea level athletes; according to Subudhi, you don’t really get acclimatization benefits until you’re at 7,500 feet or higher, and that’s a tough to achieve in a few hours’ drive.

The question is whether you actually want to. Some coaches point out that sleeping in an oxygen desert compromises an athlete’s recovery. Koop says there’s actually some efficacy behind tucking yourself into an altitude tent at night, but the response is highly individualized. “Some people do respond positively, but some actually respond negatively,” he says. Often, those negative effects show up as poor sleep, compromised recovery, and, therefore, impacted performance.

Besides, such measures come as a distant third on his list of recommendations, after getting to race altitude for endurance workouts three to four days per week (that is, if the travel time doesn’t compromise the length or quality of a workout or time spent with loved ones). And first on his list is amping up fitness levels by training at or just below the lactate threshold. “A higher threshold at sea level translates to a higher threshold at altitude,” agrees Lance Dalleck, a physiologist with the High Altitude Performance Lab at Western Colorado University.

In addition to giving an oxygen tent a try, Dalleck recommends a technique called IPC, or Ischemic Preconditioning. That means restricting oxygen to an arm or a leg (it doesn’t matter which) for about 5 minutes with a blood pressure cuff, letting blood return to the area, and repeating for a total of 20 to 30 minutes. Reducing oxygenated blood flow, even to just one part of the body, seems to switch on a full-body response, boosting overall red blood cell production.

“Hydration and nutrition can critically make or break a competition at altitude.”

“There’s some really good data to show that people who do it are less prone to altitude sickness,” he said. He also recommends taking an iron supplement while training at sea level to make sure the body is primed for acclimatization.

Another tip: practice fueling on long runs. “[At altitude] you’re under a greater environmental stress, you’re going to dehydrate more quickly, and your stomach tends to be dodgier in terms of what you can eat at altitude versus at sea level,” Dalleck says. He recommends consistently snacking on a gu or other liquid carbohydrate to stay fueled and sipping a fizzy soft drink to calm an upset stomach. “Hydration and nutrition can critically make or break a competition at altitude.”

Your Brain on Altitude

For all the decades of research scientists have put into acclimatization, there’s a lot we don’t know.

“There isn’t even a definition,” says Subudhi. By that he means there’s no objective criteria in terms of respiration rate or the amount of oxygen in an athlete’s bloodstream. To dial in the specifics, scientists from the Altitude Research Center, in collaboration with researchers from universities all over the world, flew sea level residents from Eugene, Oregon, who had never been to altitude before, to a study site in Bolivia, perched amidst the Andes at 17,000 feet. They dubbed the project AltitudeOmics.

In one study, headed by Dr. Markus Amann at the University of Utah, subjects hopped on stationary bikes to test their performance capacity at both sea level and at 17,000 feet. When they felt they could no longer go on, scientists measured the contraction force of the subject’s quadriceps to gauge fatigue and studied participants’ breathing patterns and oxygen delivery to the brain.

It was the mind, the motivation engine, that petered out first.

They found that when people reported exhaustion at 17,000 feet, it wasn’t because they’d reached maximum levels of muscle fatigue, or peripheral fatigue, which is usually what closes down a workout at sea level. At high elevations, the first thing to give seemed to be the brain.

“We call this ‘central fatigue.’ That’s when the brain just isn’t driving the activity anymore, and you’re seeing a lot of demotivation,” Subudhi says. At such a high altitude, it was the mind, the motivation engine, that petered out first.

“That’s because at very high altitudes, the brain is operating at an oxygen deficit,” Amann said.

And while spending time at altitude alleviated the effects of central fatigue, (“motivation” improved significantly after 14 days at 17,000 feet) subjects reported little or no improvement in levels of muscle fatigue over the same time period, which is one reason Amann remains sceptical that altitude training is actually beneficial to muscular performance (something for flatlanders to feel smug about).  

At what altitude does central fatigue start taking over? It’s hard to say, Subudhi says, because you’d have to separate the brain from the rest of the body to perform a truly trustworthy test. Amann’s observations indicate that the switch occurs around 13,000 feet, but Subudhi says he’s seen athletes demonstrate central fatigue around treeline in his home state of Colorado. That’s at about 11,000 feet.

Training your brain to suffer at high elevation is just as crucial as training your body.

Amann’s studies of central versus peripheral fatigue are fairly preliminary, and as such, the exact mechanisms are unknown. However, mental fuzziness is something athletes should expect and be aware of. It’s also safe to say there’s a lot going on at altitude that we don’t fully understand, and a lot of it is mental. That means training your brain to suffer at high elevation is just as crucial as training your body.

Fortunately, there’s plenty of suffering to be had at sea level, especially in the summertime. “If you can run an up-tempo 20-miler in the South with the heat and humidity, altitude is not going to touch you,” says Simpson.

Although, it doesn’t hurt to sign up for a couple of races at altitude before a big competition. For Lickteig, that means the Silver State 50-miler near Tahoe a few weeks before Western States.

“There’s absolute tactical benefit to getting up high, even just a couple of times,” says Koop. That includes getting a feel for different exertion levels at altitude and perfecting a hydration and nutrition plan.

According to Dalleck, acclimatization seems to happen a little faster every time an athlete returns to altitude. Subudhi says the physiological benefits of acclimatization may even last up to three weeks. “The lesson is you shouldn’t worry if you have to race, come down to sea level for a while, and go back up,” he says.

Besides, in terms of mental gains, there is one enormous benefit to coming from a land without mountains. “When you go from the flatlands, where you have these mundane runs you do all the time, to beautiful places like the San Juans, they blow you away. If you open yourself up to that, the distance slips by because you’re lost in that grand beauty,” Simpson says. “There are a lot of free miles out there.”