Pushing Limits and Drawing the Line: Mountain Athlete Mike Chambers on Chasing the Denali Speed Record

Mike Chambers training at high altitude for Merrell Denali Speed Project
 Chris Shane


At 7:55 p.m. on May 19, 18,500 feet up on Denali—a massif so cosmic, climbers are infinitesimal in scale and deferential to its mercilessness—Merrell ambassador and mountain athlete Mike Chambers watched his partner, Will Seeber, slip out on blue ice and careen down the Denali Pass, windblown snowpack hastening his fall.

“Please arrest, please arrest!” Chambers repeated in his head, as Seeber luckily managed to roll onto his stomach and punch his whippet into the ice. His skis were strewn some hundreds of feet up the mountain and he was clinging on by the basket of his pole, the only thing keeping him from plunging to a certain death.

Cessna aircraft at the base of Denali
Cessna aircraft at the base of Denali Chris Shane

What had started as a bluebird day—for Denali’s standards—shifted in an instant. Storm clouds charged in, forcing the two to abort their acclimatization push, only Seeber made a near-fatal mistake by trying to ski down—a decision they disagreed on. Chambers eschewed skis for crampons, finding the conditions too dangerous.

When Chambers reached his partner, Seeber looked at him, visibly shaken and emotional, and said: “I gotta get off this mountain.” Chambers secured him with an anchor, then jury-rigged a broken crampon to his foot, helping him make it down safely. Though, at base camp, Seeber had made up his mind this was the end of his expedition—a crushing blow to Chambers. Together, they were attempting to beat Denali’s speed record. Now, Chambers had to decide if he would make a go of it on his own.

The Treachery of “The Tall One”

To the average person, summiting Denali seems harrowing. (It is.) Jutting 20,310 feet into the atmosphere, Denali is a behemoth that dwarfs the Alaska Range. Being the highest, northernmost mountain in North America, its weather is tumultuous: An average summit temperature hovers around -30 or -20 degrees Fahrenheit with squalls reaching 70 mph, though with the wind chill it can drop to -118 and freeze a body instantaneously.

Mike Chambers warms up after Denali descent with 70 mph winds
Mike Chambers warms up after a descent with 70 mph winds Chris Shane

But it’s a combination of elements that make it so wickedly dangerous for mountaineers. Science suggests pressure altitude provides the greatest implication, as it’s influenced not just by true altitude, but temperature fluctuations, latitude, and other meteorological variables. Because of this, climbing Denali feels similarly to Argentina’s Aconcagua, the highest peak in South America (22,841 feet), and Nepal’s Everest (29,029 feet), the largest in the world.

But to Chambers, 33, the gravity of it all demands that you rise to the occasion. A place of such natural grandeur rouses a different kind of motivational draw to push limits.

“As I get older and experience the mountains more, I’ve been more and more intrigued by this concept of giving the mountain your all,” Chambers says. “I didn’t want to just climb the standard route in a traditional fashion. Denali has always been a mountain worth an honest effort, and that’s why a speed attempt was more appealing to me.”

I’m intrigued by this concept of giving the mountain your all…Denali Has Always been worth an honest effort.

Of course, Chambers isn’t your average person. As a Merrell ambassador and endurance athlete, he’s led 15 high-altitude climbing expeditions (two on Everest) and competed in ultra cycling and running races around the globe. He also likes to embark on long-weekend adventures—something he and his buddies have coined “Beat Monday.” They have 64 hours (Friday night to Monday morning) to complete their objective, which is to eke out the most thrills possible over the weekend in the hopes of inspiring more adventurers to break the norm and do the same.

“We went down to Ecuador to try to climb Cotopaxi, but Ecuador’s just notorious for brutal weather, since you’ve got the Andes and the rainforest, so storms are constant,” Chambers says. “It took 15 hours of travel to get to our hut, but it was just totally soaked, with 60 mph winds, so we just turned around and came home. It was kind of stupid, but we still had a lot of laughs… and drank a lot of alcohol. We try not to take ourselves too seriously.”

Though for Denali, Chambers was gravely serious. He had to be if he wanted to break the record, and, more importantly, stay alive. The time to beat was 11 hours and 48 minutes, set in 2014 by Kílian Jornet, a Spanish ultra-athlete with an ungodly number of records in his name. He shattered the previous time by a lung- and quad-busting five hours.

Historically, speed attempts are done solo. The reason being “it’s very rare to have a partnership where everything goes 100% according to plan, where everyone’s on the same page fitness-wise, as well as mentally and experientially,” Chambers explains. But as a new father, Chambers’ priority has become minimizing risks, and that meant having a partner.

Will Seeber, Mike Chambers, and Jason Antin
Will Seeber, Mike Chambers, and Jason Antin Chris Shane

The Strategy: Breaking the 11-Hour Benchmark

Chambers’ goal was to do the journey in under 11 hours, following the West Buttress Route (with the Rescue Gully variation), the most popular among athletes. It’s roughly 34 miles round-trip with 13,500 feet of elevation gain. For reference, most climbers take about two weeks to complete it.

Logistically, traversing Denali is quite different from other treks, too. On Everest, yaks carry the majority of your gear to base camp for the month or two that you’re on the mountain, sparing your legs and curtailing muscle breakdown.

“But on Denali, you fly into the base at 7,000 feet, and you need to bring every single thing you’ll need for however long you plan on being there,” Chambers explains. “In our case, that was 20 days’ worth of food and gear, and I brought doubles of a lot of equipment. I didn’t want my skis, for instance, to break and that be the reason why I wasn’t able to continue on.”

Mike Chambers, Jason Antin, and Will Seeber packing sleds with gear
Mike Chambers, Jason Antin, and Will Seeber packing sleds with gear Chris Shane

In all, Chambers and Seeber each had about 175 pounds split between their pack and sled. On the lower glacier, most of that weight is on the sled. (“You’re like a pack mule,” Chambers says.) Then, when the gradient becomes steeper and you start climbing, you shift a lot of that weight into the pack so the load doesn’t pull you off the mountain.

“When you do a big day, carrying 175 pounds at 13,000 feet on a mountain like Denali, your body can’t recover,” Chambers says. “You’re acclimatizing, so you’re basically dying up there. You’re deteriorating by the day.”

Base camp is located at 14,000 feet. This is where you establish your cook tent and lay out your gear. At this point, your pack will never weigh more than 30 or 40 pounds.

“It’s like this mission to get up to 14,000 feet,” Chambers says. “It’s really hard, really challenging, really demoralizing, but once you get up there you can just kind of relax.”

Sort of. You still need to climb Denali.

“I knew the only way I would have a shot at this is if I surrounded myself with the best,” Chambers says. “I really went over the top to make sure I had the smartest minds in the game helping me.”

Mike Chambers training for Denali in Colorado
Mike Chambers training for Denali in Colorado Chris Shane

That meant teaming up with coach Scott Johnson of Uphill Athlete to craft the programming; Jared Berg from Colorado University Boulder sports medicine to perform monthly tests, like VO2 and threshold, to map progress; meteorologist Chris Tomer to give real-time forecasting updates; high-altitude doctor Peter Hackett to design an acclimatization profile; and Jason Antin, another Merrell ambassador and mountain athlete (as well as a good friend of Chambers), to serve as logistics manager.

“When Kílian made the record, he had a lot of things go wrong—issues with conditions, acclimatization—and he ended up breaking trail for a long time, which slowed him down,” Chambers says. “We really analyzed his data and geeked out on his splits. His vertical ascent rate on Denali was 1,300 feet per hour, considerably less than what would be his standard ascent rate on another mountain of equal hight, say Aconcagua, which was more like 1,500 feet per hour. We saw that as low-hanging fruit in a lot of ways.”

The quick-and-dirty strategy in a long, grueling six-month training period: Maximize acclimatization while maintaining fitness. To break the speed record, they planned to be on skis as much as possible.

Mike Chambers training for Denali in Colorado
Mike Chambers training for Denali in Colorado Chris Shane

Training and Fueling to Race Up Denali

For the brunt of his training, Chambers worked out in his home state of Colorado, doing 26 to 30 hours of uphill training per week (not including time spent getting back down the mountain or cross-training). That meant pistoning up steep vertical ascents with mountaineering gear at a local ski resort—climbing up, skiing down—again and again. Typically, he’d do two weighted (50- to 60-pound) pack-carry sessions a week, either on skis or on foot; some trail running just to maintain his turnover; and a bit of high-intensity work. Roughly 80 percent of the training load was in “Zone 2”, 70-80 percent of Chambers’ maximum heart rate, to build a massive base.

“In order to maintain the upper level of my Zone 2—to keep my heart rate at 155 beats per minute for hours—I needed to consume 700-800 calories per hour to keep my body moving without bonking,” Chambers says. “To decrease my body’s reliance on carbs, I did fasted workouts for four months. By the time I did my final metabolic test, I’d increased my body’s fat utilization by 300 calories per hour, which meant I now only needed to eat around 500 calories per hour.”

Chambers’ diet wasn’t exactly keto, but it was lower in carbs in the beginning to lean out, then became more carb heavy toward the end to maintain his fitness. He also abstained from alcohol three months out. On the mountain, though, clean eating goes out the window. The rule of thumb becomes anything you can stomach.

Jason Antin and Mike Chambers grocery shopping for Denali
Jason Antin and Mike Chambers grocery shopping for Denali Chris Shane

“One of the issues with altitude is you lose your appetite pretty quickly and nothing sounds appealing,” Chambers says. “We bring a lot of processed, refined sugar—sweets that are easy to eat quickly, like Reese’s Peanut Butter Cups—stuff we don’t normally allow ourselves to eat much of at sea level.”

At base camp, the team cooks more substantial meals—bacon and eggs, burritos, pasta, and rice. Though on nights when they’re not feeling too hot, they go back to the Snickers, Fruit Gushers, and Pop-Tarts.

Like any other athlete, rehab and recovery were integral to Chambers’ regimen. He started working with Alex Guerrero, Tom Brady’s personal trainer, a couple years ago after he shattered his heel in a bouldering fall. He’s mindful of his body’s pliability. To maintain it, he foam rolls and stretches every day. Because of this, he says he needs considerably less recovery time than normal. One day per week was dedicated purely to a low-intensity workout to flush his legs. In all, it was six days a week of high-volume work for three weeks at a time, then Chambers would have a recovery week where he’d cut the volume by about 60 percent. He’d build up again to begin a new training block, which would have more volume each time. Interestingly enough, Chambers didn’t taper ahead of Denali.

on Denali, your body can’t recover, so you’re basically dying up there—deteriorating by the day.

“There’s a lot of literature right now that suggests it’s actually ineffective, and some of the best endurance athletes in the world have been laughing off the prospect of a taper, Kílian included,” Chambers says. “Sure, reducing volume to maximize recovery is important, but the percentage you reduce in a traditional taper induces a detraining phase.”

To leverage pre-acclimatization, Chambers slept on 14ers in Colorado and, three weeks prior to Denali, he slept in an altitude tent—the equivalent of sleeping in a plastic bubble—at home. However, he and his team weren’t convinced of the altitude tent’s efficacy, and it reduced his quality of sleep. Chambers was also skeptical of hypoxic workouts. He wore a mask that simulates breathing at 10,000 feet to perform short, intense workouts on a treadmill or stationary bike, but stopped because he didn’t find it helpful.

“I was definitely prepared for Denali,” Chambers says. “Based on the numbers, me and Will’s vertical ascent rate was just as good if not better than Kílian’s when we left for the mountain. Physically and mentally, I felt better than I have in my whole life.”

Mike Chambers with son Max at Brainard Lake
Mike Chambers with son Max at Brainard Lake Chris Shane

An Adventure Athlete’s Ultimate Dilemma: Risk vs. Reward

The irony in that preparedness was deciding whether to take the risk of a solo speed attempt now that Seeber was out. The time spent away from his wife, Leila, and son, Max (13 months old); the team of people who made sacrifices to prepare him and Seeber; the sheer amount of effort it took to get to this point—everything compounded together weighed heavy on Chambers.

“I was really upset,” he says. “That accident—that poor decision—led to a really close call and, because of that, I was facing this decision to take what I considered to be a significant risk for the objective.”

Never before had Chambers been forced into a situation where his willingness to take risks and the weight of those consequences was projected through his son’s eyes.

“I would go back and forth thinking, ‘If I can pull this off, he’d be so proud of me. It’d be amazing—just incredible,'” Chambers recalls. “But at the same time, if I fall into a crevasse lower on the glacier because I’m traveling solo and unroped, and no one knows where I am, and I just have to sit there for hours or days until I die, am I going to be thinking to myself he would have been so proud of me that I went for it? No, I’m going to be thinking, ‘Wow, I fucked up so bad.'”

As an athlete in the adventure space, Chambers—as well as people like Alex Honnold—have an interesting dilemma. Unlike traditional sports where aging is the biggest hurdle in one’s career, climbers and mountaineers face ever-growing risks. The more you succeed, the more you’re forced to push the boundaries of human limits. You’re faced with tackling greater challenges and fiercer perils.

It’s something Chambers has been grappling with. He says: “What does that mean for the ultrarunner or climber who wants to become a mom? Or someone who wants to settle down and get married? What does it mean for people when they start taking on other responsibilities? Does it mean that they just need to move on with their lives?”

It’s up to the athlete to draw the line, even if that means accepting a past lifestyle is potentially no longer feasible.

“My wife always writes me these letters that I’m allowed to open at certain points during my expeditions,” Chambers says. “This time she wrote one from Max. I was supposed to wait until the speed ascent, but I opened it on the morning I was trying to decide what to do. It was really cute and funny and introspective. Reading it was the last straw for me, and gave me the strength I needed to make the decision not to go for the record.”

Card from Mike Chambers' wife, Leila
Card from Mike Chambers’ wife, Leila Courtesy Image

After an existential crisis of sorts (“Am I still going to pick up sponsorship? Will I no longer have opportunities like this? Do I have to reinvent myself and start something new?”), Chambers tagged the summit of Denali with Jason Antin. On the way down, the two got caught in some ferocious wind.

“Later, I told my mother-in-law the story and she said to me, ‘Mike, we don’t talk about things that didn’t happen.’ And I’m like, ‘Damn, you just burned the shit out of me!’ I kind of love that, actually.”

Pushing New Boundaries

About a month after Chambers left Denali, Swiss-Ecuadorian alpinist Karl Egloff beat Denali’s speed record. His time? A blistering 11 hours 44 minutes. His ascent from base camp to the summit was 7 hours and 40 minutes via the West Buttress, beating Jornet’s record-setting time by over two hours. Instead of skiing down, Egloff ran down the mountain.

“He’s one of the biggest sources of inspiration for me, and I hope he gets all the recognition he deserves, because it’s really remarkable,” Chambers says. “What he’s done is mind-boggling. I don’t think that mountain will see an ascent faster that Karl’s for many years to come.”

For now, Chambers will continue to hunt for new adventures, like smashing the Cascade Trifecta record. On July 6, Chambers and his partner Erik Sanders summited the three highest peaks in the Pacific Northwest—Mount Rainier, Mount Adams, and Mount Hood—consecutively in a time of 22:53:21 (the previous record was 28 hours and 1 minute). That’s a cumulative 35 miles and 21,000 feet of vertical gain (plus 208 miles of “reckless driving”).

As for breaking that 11-hour mark on Denali, though, Chambers thinks that record is still feasible for skiers—maybe even for himself.

“I haven’t ruled it out,” he admits. “That’s for sure.”