Things didn’t go as planned for the reigning Western States champ at The North Face Endurance Challenge, but she fought through it. (And drank a lot of Coke.)

Scientists can forecast marathon performance fairly accurately. But for longer distances, things get complicated.

Dave Mackey was the first person to run the Leadville Trail 100 Run with a prosthetic leg

Maggie Guterl became the first woman to win the Big Dog Backyard Ultra, the race with no end

After switching from marathons to ultras six years ago, Boulet continues to blow away the competition

By offering minimal prize money, the sport’s most prestigious race might be excluding the best runners

Yes, raw speed helps. But it isn’t everything.

Changing the Way We Handle Adversity

When Mirna Valerio first began running ultramarathons, she immediately got a lot of attention—but not for the reasons you might expect

'Leadman: The Dave Mackey Story' chronicles its namesake character making a return to the iconic Leadville 100 ultramarathon

She's the first person to finish the Leadville Race Series and the Grand Slam of Ultrarunning in a single season

After spending days in the Arctic wilderness, running 100 miles on trail is a piece of cake

Walmsley just bested his own time by an impressive 20 minutes

Or, the story of how I ate snacks and felt pain

The elite competitor and full-time lawyer talks to Tim Ferriss about training and nutrition

Gene Dykes, the world’s fastest 71-year-old marathoner (2:54!) says yes, and tells how he combines frequent ultras and fast marathons.

Making your way over an 800-mile trail through deserts and mountains in less than 16 days is no picnic—except for those gas-station resupply stops

This is a recap of the Nine Trails 35-miler​​​​​​​ in Santa Barbara, California, showcasing some of ultrarunning's top talent

From Black Diamond, 'Nolan's 14​​​​​​​' chronicles runner Joe Grant’s FKT attempt at the film’s namesake trail

Marc Peruzzi’s recent column about trail work clearly touched a nerve in the running community. Part of his argument is fair criticism, but he got some important things wrong. 

In 'A Long Day Out,' the viewer follows Kilian Jornet on a 56-hour adventure through his home mountains in Norway

Performance and comfort, mile after mile

In an effort to raise awareness for the global water crisis, runner Mina Guli is attempting to complete 63 marathons in 63 days

Earlier this year, the iconic race announced a new policy for transgender competitors. Here's how the decision came together and why it's important. 

With more participants in ultramarathons, more competitors are experiencing the joy of hallucinations and other ailments. Exile Medics steps into a newly necessary role.

The Nathan VaporHowe 12L vest is simple and lightweight, and features a 1.8-liter hydration bladder that doesn't slosh around on your back

Katie Arnold, author of the new memoir Running Home, talks about the unique healing power of endurance sports

The Halo was designed for ultramarathons and all the extra gear they demand. The front bottle pockets keep water at the ready but also have lash points to holster trekking poles, while the pockets on the lower straps hold your phone, gels, or bars. The bladder-compatible Halo also has two…

Osprey blends running-vest performance with backpack capability in the Duro, which has four front pockets—two extra-large stretch-mesh ones for a phone and water, and two smaller ones for food. Six liters of space in the main compartment is enough for a jacket, headlamp, and other accessories, plus the included 1.5-liter…

The Ultra Pro 2in1 name is appropriate, since this model comes with a ten-liter pocket that completely detaches from the vest. Use the vest solo for fast, short runs, or attach the pocket for longer missions when you’ll need more food and gear. It comes with two long-straw flasks and…

The Trail Mix 7 is built specifically to better fit around a woman’s bust. Compression straps that bring the load tighter to your back, reflective hits for 360-degree visibility, and seven liters of storage (in addition to the two-liter bladder) are icing on the cake.

A 15-liter backpack built on a running-vest chassis, the Distance is a hybrid hauler with dual front stretch pockets for snacks, a bladder sleeve, and dual side-compression straps that keep the load close. And its water-resistant, 210-denier nylon helps keep gear dry.

What kind of sadist creates the hardest race in the world? We sent our writer to find out.

On July 17, 2017, thru-hiker Joe McConaughy set out to claim the fastest known time for a self-supported traverse of the Appalachian Trail

Runner Dylan Bowman​​​​​​ recounts a harrowing tale in which he faced off with a yellow Lab in the midst of a 100-mile race

In the wake of a bizarre physical attack and the death of her father, Katie Arnold felt paralyzed by the anxieties of parenthood and being a woman alone in the wilderness. She got through it the same way she’d always done, by lacing up and hitting the trail. An exclusive excerpt from her new memoir, Running Home.

Go a little faster and a little lighter with the Duro handheld water bottle. It holds 8.5-ounces of your favorite hydration and has a small zippered pocket for small essentials like cash and your driver’s license.

The coach, NOLS employee, and professional ultrarunner attributes part of her success to her hectic schedule

The Western States Endurance Run is one of the most iconic ultramarathons, but it hasn’t always been that way

Former Navy SEAL and endurance athlete David Goggins insists that discomfort is the key to self-improvement

In the age of specialization, it’s refreshing to see a big name get outside his comfort zone

Real-world data shows elite ultrarunners average 180 steps per minute—and that means nothing

Catching up with the newly-crowned 24-hour racing champion

Dag Aabye is known around Vernon, B.C., for his astonishing fitness. He's 75.

Taylor Nowlin came out of nowhere to break Ida Nilsson’s brand-new record by over three minutes

As the Camp Fire continues to devastate Northern California, the canceled North Face Endurance Challenge provided an opportunity for runners to do some good, and gain some perspective

This Utah 50K and half marathon event is taking one small step toward closing the wage gap

Five years ago, the Swedish runner was beset by long-term injury. This past weekend, she set a new bar for traversing one of the most iconic landmarks in the U.S.

At Big’s Backyard, you never know how long the race is going to last, because there is no finish line

‘3100: Run and Become’ explores moving meditation all over the world, from a race around a single New York City block to a 1,000-day run for Japanese monks

Long-distance running can be tough on the stomach. These foods can help.

A new study explores attitudes toward performance-enhancing drugs in the ultrarunning world

Five favorite books from the elite endurance athlete and environmental activist

Ultrarunner Hillary Allen took a life-threatening fall last year at the Tromso Skyrace in Norway.

Sue Johnston has been setting FKTs for decades and inspired a generation of ultrarunners along the way. If you've never heard her name before, that's by design.

‘Is This Fun’ follows ultrarunners John Ellis and Jo Kyaw as they compete in the 9 Dragons Ultra race in Hong Kong.

Our running columnist is an expert in the track and road running scenes, but the ultra world isn’t exactly his beat. He dove in head first at UTMB.

Bucket List FKT, from Columbia Sportswear, follows McConaughy as he set his sights on Ireland’s Wicklow Round.

Mentors: Hillary Allen, from the North Face, chronicles her recovery and how she’s found a new pace within the activity that she loves.

Devon Yanko was sexually abused as a teenager. It took hundreds of miles for her to run away from the trauma.

‘In Constant Motion’ follows ultrarunner, Adam Campbell, as he returns to trail running after a life-threatening fall.

The Spanish ultra-athlete has spent the past decade crushing a generation of elite rivals and redefining the limits of human endurance. But when he notched back-to-back speed ascents of Everest in 2017, critics pounced on the claims.

Ultrarunner Harvey Lewis is vying to clutch the fastest known time for a supported run on the 2,190-mile thru-hike—and so far he's on pace

Jim Walmsley’s Western States run was remarkable. But how does it stack up against these other extreme distance running feats?

Dauwalter just won the prestigious Western States Endurance Run in a blazing fast time. We can all learn something from her training philosophy.

We asked eight athletes what socks they'll be wearing for the Western States Endurance Run

This movie follows the Coconino Cowboys as all 5 runners worked to qualify for this weekend’s Western States race.

While recovering from a terrible accident, the ultrarunner discovered a new part of her identity that went beyond her sport

Fast, cocky, and more than a bit reckless, the 28-year-old might be the best ultrarunner in the country. And he's finally proven himself over a full 100-mile race.

The elite athlete had an explosive start to her career, becoming the first woman to win back-to-back UTMB Championships.

If we truly want more women in this sport, it's time to change the system for entering races

One of the craziest speed records in ultrarunning takes athletes from the top of the canyon, down to the bottom, and then all the way back up again—twice.

This film 'Fastest Known Time' gives context to a movement growing within the trail community: FKTs.

Ultrarunner Dylan Bowman ran from Usal Beach to Mattole Beach fifty-five miles north in just over eleven hours. 

Hal Koerner's guide to running your first 50K, including key intensity workouts and a 16-week training plan

From filmmaker Noam Argov, Running Across California chronicles Ali Butler-Genesk’s attempt at a ‘fastest known time’.

A minute-by-minute account my attempt to run across the Grand Canyon—twice

The vests, bags, belts, and more that top athletes use to stay primed while they push