Get access to everything we publish when you sign up for Outside+.
Jack Kuenzle can tell you, moment for moment and mile for mile, how his progress compared to that of Kilian Jornet—yes, that Kilian Jornet—during the 12 hours, 23 minutes, and 48 seconds it took him to run the Bob Graham Round, a mountainous 66-mile route around England’s Lake District. Jornet, the famed Catalan runner, set the fastest known time (FKT) on the route in 2018, with photographers and a film crew in tow. Kuenzle spent more than a year plotting his own attempt at the record.
Outside Long Reads
This bi-weekly e-mail newsletter features our strongest writing, most ambitious reporting, and award-winning storytelling about the outdoors.
On the morning of September 2, Kuenzle, who is American, departed Moot Hall, a medieval courthouse in the town of Keswick, which is the official start and finish for the competition. As he jogged up the slopes and picked his way through scree fields alongside several runners who paced him, a race was going on inside his head.
“We’d get a couple minutes up on him [Jornet], and I’m thinking, Oh, wow, we’re doing great,” Kuenzle told Outside. “But when I looked at the maps afterwards, for the entire day, until the very end, I could have turned around and seen him.”
Kuenzle, 27, was slowed by dehydration during the second half of the effort. But he eventually pulled ahead of his invisible foe and had enough time to change from his trail-running shoes into racing flats for the final few miles, which are paved. When Kuenzle ascended Moot Hall’s steps, he had beaten Jornet’s time by a whopping 29 minutes.
A small group of onlookers cheered, and that was all the fanfare he got or needed. His satisfaction came from setting a punishing mark that, of course, may be broken in the future by a different runner.
“The cool thing with FKTs is that the competition is never really over,” Kuenzle says. “Someone is going to beat my time. It’s just a question of when.”
The Newest FKT Superhero
If you haven’t heard of Jack Kuenzle, you’re forgiven, although it’s about time to get with the program. He’s been toppling fastest times on trails in the United States for the past two years, and he has his sights set on even longer and more daunting records around the world.
Earlier this year, Kuenzle turned heads when he set the wintertime FKT on Oregon’s 11,249-foot Mount Hood while wearing little more than sunglasses and a pair of skin-tight spandex shorts. The feat won him attention from outdoor media, including this publication. The story seemed too weird to be true: a former hockey player and Navy SEAL was breaking speed records at a precipitous rate. Beating Jornet’s time vaulted Kuenzle to a completely new level. And he can already make a case for being included in the most elite circles of mountain athletes.
The Bob Graham Round was part of a whirlwind set of speed records established by Kuenzle. In the summer and fall of 2021, he set new fastest times on a number of routes in the northeastern U.S., including the 45-mile Hut Traverse and 18-mile Presidential Traverse, both in New Hampshire, and the 21-mile Adirondack Great Range Traverse in New York (his FKT was beaten shortly thereafter). After those, Kuenzle headed west for the winter to chase ski-mountaineering FKTs, and he did so with limited skiing experience—he’d only started backcountry touring in 2019. But his natural prowess served him well on snow. He set the fastest time for a ski ascent on California’s Mount Shasta and the round-trip ski FKT on Mount Tallac, also in California, before setting the best time on Mount Hood.
Kuenzle returned to New England this past spring and established a new fastest time on the White Mountains 100, a 104-mile slog across New Hampshire that includes the Presidential Range and one of the gnarliest section of the Appalachian Trail. The accomplishment represented a moment of redemption for him—he had tried for the FKT there in 2021 but quit after 80 miles due to trench foot. He spent the rest of this summer charging across England’s mountainous Northern Fells and Scotland’s Highlands, setting a new fastest time on the Tranter Round before going to the Lake District to tackle the Bob Graham Round.
Over the course of 2022, Kuenzle’s reputation slowly built within the FKT community, where the competition for records has become more heated in recent years. Even in this tight-knit world, Kuenzle stood out. “He’s a total beast,” says Allison Mercer, project manager and social media coordinator for the Fastest Known Time website, which tracks route records. “He’s really raising the profile of these routes.”
Racing for Satisfaction, Not Results
Legendary times and attempts on iconic routes have long been kept alive in local lore, but documented FKTs are a newer phenomenon. When Fastest Known Time was launched in 2000, the website was designed to verify these records and house them in one place. At first it was a lightly moderated message board, but over time it has grown into the recognized authority for the loosely regulated sports of long-distance hiking, running, and skiing. According to site rules, times have to be human powered, done at least halfway on foot, and verifiable—usually by a GPS tracker. Other than that, chasing FKTs has very few rules. You don’t have to pay to play, and anyone, at any time, by nearly any means, can head out and try to run an established route—or make a route and submit it for approval—faster than anyone else has done it before. Some runners pursue records with support (pacers, aid stations, and food), while others take them on unsupported.
“You don’t get paid, there’s no prize, there’s no certificate,” says Mercer. “You get your name on a message board. If you’re doing it, you’re doing it for yourself.”
It’s an approach that appeals to Kuenzle, and in many ways seems suited to his personality and current priorities. At a time when elite mountain sports are dominated by corporate sponsorships, Kuenzle declines to work with brands. He says he wants to keep his efforts independent.
Mountain running supports a thriving series of international races and professional events, but Kuenzle is focused entirely on route records, not organized competition. He appears to be pushing himself solely for the purpose of doing it. When I spoke with him in September, his analytical side came through early during our conversation. He spoke at length about optimizing conditions for pursuing speed records and about finding new ways to push himself. He seems to have an insatiable need to go harder, which expresses itself in his hunger for FKTs.
“Racing just introduces more constraints,” said Kuenzle. “You don’t have as many opportunities to be creative.”
His pursuit of FKTs sets him apart in the small community of top mountain runners. Most of these athletes race for a living and pursue FKT challenges as personal accolades. Few target the fastest times as their primary goal.
“He’s basically reinventing the way that people do these routes,” says Ryan Atkins, the current world champion of Spartan racing and a professional endurance athlete with several FKTs to his name. “Jack is one of the few athletes who legitimately doesn’t race but just trains specifically for these routes and just pushes himself so hard outside the arena of modern, large-scale races.”
Atkins met Kuenzle in the Adirondacks in 2020, when Kuenzle was scouting the Great Range Traverse, which Atkins set the record on in 2019. Atkins was impressed by the sheer quantity of miles Kuenzle had logged on the rugged terrain. “I’ve run the route maybe 12 times ever,” he says. “And Jack did it, like, seven days in a row or something. The volume that this guy can do day after day is just otherworldly.”
Most of these athletes race for a living and pursue FKT challenges as personal accolades. Few target the fastest times as their primary goal.
Kuenzle toppled Atkins’s FKT by about 23 minutes. Two months later, Atkins ran the route again and reclaimed his record by three minutes. The two were cheering each other on then and have been since.
This camaraderie is common in mountain running. Athletes are often generous with sharing beta, and FKT holders seem genuinely excited when someone challenges them. Kuenzle and Jornet didn’t speak before his attempt on the Bob Graham—Kuenzle admits he was too intimidated to reach out to Jornet, who he has long looked up to—but the Spaniard congratulated him afterward on Twitter.
“The worst thing that could possibly happen is we put up a time and nobody ever races it, nobody even tries for the rest of eternity,” Kuenzle says. “And then the best thing that can happen is a ton of people come and they all have a great day, but nobody’s quite good enough to beat your time.”
As Kuenzle sees it, the more people who attempt an FKT, the more legitimate the effort and the route become. “If Killian came back next week and did the Bob Graham Round and I was here, I would absolutely want to help pace, discuss lines and tactics, whatever would help him maximize his potential on it,” Kuenzle says.
But supporting other FKT attempts is about more than making records more robust or putting out good “runner karma.” Kuenzle also wants to help other athletes for one of the same reasons he’s drawn to the sport itself. “Part of it, for me, is just pure curiosity,” says Kuenzle. “Like, how fast is possible? It’s cool to be part of that project, even if your time gets beat.”
From the Suburbs to SEAL Training
Kuenzle’s focus on local speed records has led him to a vagabond lifestyle, one structured almost entirely around traveling as cheaply as possible. He lives in a camper, which gives him motility and keeps costs low. He works as a coach for the performance company Evoke Endurance and says he earns just enough to sustain his passion without sacrificing flexibility or training time.
The job also allows Kuenzle to maintain his independence—something he believes he’d forfeit if he signed a cash sponsorship with an outdoor brand.
“Racing and outdoor sports have become so commercialized,” Kuenzle told me. “And I just see how people turn into these cookie-cutter personalities, or only say what their sponsor wants to hear. I don’t want to do that, so I’m not going to.”
Dwelling in a camper and taking on FKTs are just part of the latest chapter in a life that has already seen a few twists and turns. Kuenzle, who was born Robert Jacob but took the name Jack, grew up in Roxbury, Connecticut, a two-hour drive north of New York City, and he played ice hockey through high school. He went to Yale and enrolled in the Naval ROTC.
In high school and college, Kuenzle ran for fun, but he never stood out for his physical talent. Noah Baily, a friend from Yale, told me that Kuenzle finished behind him in all of their ROTC fitness tests that involved running. Baily isn’t surprised that Kuenzle has found success in chasing FKTs on foot, though. “It’s Jack’s fundamental state of being to push himself,” he says.
Another friend from his ROTC days, Adam Straus, says Kuenzle still looked like a kid when he started college, but his boyish looks cloaked an inherent toughness. Once, during a major snowstorm, Kuenzle headed out for a long run, looking totally underprepared. “For no discernible reason, Jack went for a 20K run in shorts and a T-shirt,” Straus says. “That was the first time I was like, This guy is profoundly disturbed. Like, he’s probably going to be able to do anything that he really sets his mind to.”
According to Straus, Kuenzle told friends that he wanted to become a Navy SEAL from a young age—an idea that some of his cohorts shrugged off. Straus admits that even he doubted that his friend, who “probably weighed, like, 140 pounds,” would be able to hack it.
Kuenzle’s military interests were tied to family background—his father was in the Marines, and he says he had always planned to serve as well. Kuenzle wasted little time in pursuing that goal: just eight days after graduating from Yale, he drove to San Diego to begin his first week of SEAL training at the Naval Amphibious Base in Coronado Beach.
The training regimen for the Navy’s elite fighting force has garnered international headlines for its brutal nature. Hopeful trainees must endure physical and psychological stresses while pursuing the yearlong instruction. Kuenzle says the “leviathan” reputation is what drew him to the SEAL program.
“You know how Alex Honnold has something wrong with his brain, where he just doesn’t have fear?” Kuenzle says. “I’ve wondered if I have something wrong with my brain that makes me perceive physical exertion differently.”
Kuenzle says his time in the SEALs was the “best and worst of my life.” He never saw combat, and he admits that his personality didn’t always fit with Navy attitudes.
“I really respect all the guys who are able to fully buy into being a SEAL, because the job really takes 110 percent commitment to do well,” he says. “There’s a part of me that was just too contrarian and independent to go head over heels for it.”
Simultaneously, Kuenzle began to pursue a passion for long-distance running. As a SEAL, he developed physical and mental toughness that would help him in his FKT pursuits. During a period of SEAL training known as Hell Week, when a sizable portion of trainees abandon the program, he discovered that he had the mental fortitude to push his body beyond where he thought it could go.
“If I learned anything going through training, it’s that there are really no effective strategies for coping with pain,” Kuenzle says. “You just gotta take it, basically. Nothing was going to make it better, and it was OK to think about quitting.”
No Racing—for Now
There’s another element of Kuenzle’s backstory that explains his aversion to organized competition and cash sponsorships: a privileged upbringing. Roxbury is among the more affluent communities in Connecticut, where the average price of a home hit $1.3 million in 2022, according to the National Association of Realtors. Kuenzle attended a private high school before entering Yale, and years spent living alongside the wealthy shaped his approach to his current pursuits.
“The idea of the amount of privilege I have sits poorly with me,” he says. “So possibly that’s why I don’t want a sponsor, because it’s feeding into that and feels like another advantage.”
The privilege that Kuenzle references isn’t just about private school and Yale—it’s about his ability to pursue athletics for his entire life. Race victories and a sponsor paycheck, in his eyes, turn his running accomplishments into just another product of the advantages he’s enjoyed in his life instead of his own skill and effort.
“And I know there’s still huge privilege that plays into it,” Kuenzle says. “But at least I can pretend it’s not just a reflection of my environment, my background, my parents.”
“Part of it, for me, is just pure curiosity,” says Kuenzle. “Like, how fast is possible? It’s cool to be part of that project, even if your time gets beat.”
Pursuing FKTs doesn’t violate Kuenzle’s thoughts on privilege—the efforts are simply a by-product of his passion for pushing himself beyond boundaries. At the moment, he has no definitive plans for a new speed record in the mountains or to pin on a racing number. He says the list of competitive and challenging FKT routes that appeal to him is shrinking, and he’s considered expanding his scope to include gnarlier, more dangerous mountaineering routes that encompass Class 5 terrain.
And yes, Kuenzle has also considered participating in an organized race or two. France’s Ultra-Trail du Mont Blanc and Colorado’s Hard Rock 100—two of the biggest ultramarathons on the calendar—are on his radar, alongside a handful of ski-mountaineering races and the Mount Marathon in Alaska.
Kuenzle does not, however, see himself leaving FKTs behind completely. Instead, he hopes that other elite runners will follow his lead and start going after them seriously, not just when they have a gap in their racing schedule.
“Part of my motivation for doing this is that I’m hoping it will bring more people to do it in the future,” Kuenzle says. “I really do think that FKTs are much better than racing, and that a lot of people would enjoy this type of competition.”
Even if Kuenzle eventually decides to trade FKT challenges for organized races, the shift isn’t likely to alter how or why he pushes himself to go faster.
“I could race one year and come back and do FKTs the next, it wouldn’t change me,” he says. “It would just be a new challenge.”