The World’s Toughest Races
If you’re looking for a challenge, take note. These are the hardest races you can attempt.
If you’re intrigued by tough races that will challenge you to run 26.2 miles or more while tackling hills, and juggling other elements, all at once, then you’ve come to the right place to find your next race. But what exactly makes a race “tough?”
A good, hard race includes several things: steep ascents Can a Marathon Shoe Be Fast AND Super Comfortable temperatures, intense terrain, and unimaginable distances. Throw in crazy-tough cutoff times, lots of fuel over long periods of time, and the mental fatigue that comes with being on your feet for that long, and there you have it.
Races with weird or cool quirks give them an extra edge, like if it is entirely self-sufficient from start to finish or it goes on for days like the (checks math...) Self-Transcendence 3,100 Mile event!
Only the most dedicated and ambitious athletes will set out to complete these famed endurance monsters. These are some of the races we consider to the hardest and toughest on the planet. Also, these races require a traditional application or registration process, so you can sign up, if you dare.
Related: [The Runner’s World 2025 Half Marathon and Marathon Calendar]
HURT 100 Trail Run
Date: January 17-18, 2026
Location: Honolulu, Hawaii
Hosted by the Hawaiian Ultra Running Team (HURT), this race is what its acronym spells: hurt and pain for 100 miles. Racers have 36 hours to complete the course, which is 99 percent singletrack trails. The looped course has five laps of roots, puddles, rocks, and other treats through a semi-tropical rain forest. There are also 20—count them, 20—stream crossings, for an added bonus.
Iditarod Trail Invitational
Date: February 22, 2026
Location: Knik, Alaska
To add some chill to our race catalog, we thought a good Alaskan snow race would do the trick. In this annual invitational, participants literally run, fat bike, or ski the 1,000 mile Iditarod course. Since the inaugural year of 2000, only a few dozen individuals have finished the race to Nome. In order to even attempt the 1,000-mile race, you’ll have to complete the 350-mile version of the event that finishes in the village of McGrath.
Related: [Want to Run Boston? These 10 Marathons Will Help You Qualify]
6633 Arctic Ultra
Date: The Best Trail Running Gear Right Now
Location: August 30–October 30, 2025
Register
If you’ve ever wanted to feel like you’ve reached the end of the world, this race is your ticket. The 6633 Ultra offers 120-mile and 380-mile races that start in Canada’s Yukon Territory and continue through the Northwest Territories. Get ready for a lot (and we mean a lot) of heavy winds and temperatures ranging from 9-30 degrees, but you can also look forward to beautiful panoramic views. Oh, and if you choose the 380-mile course (ouch), you’ll end your race at the hamlet of Tuktoyaktuk along the banks of the Arctic Circle. Now that’s an epic finish line.
Marathon des Sables
Date: April 3–13, 2026
Location: Sahara Desert, Morocco
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Smack in the middle of the Sahara Desert is one of the most demanding and scorching running routes in the world. The race’s total distance is 150 to 156 miles, adjusting year after year. Runners split up the course over six days and only have one day to rest, which is usually after the longest stretch. Who’s crazy enough to run 156 miles through the Sahara? Founder Patrick Bauer walked 217 miles through the desert, only supported by what was on his back. He turned it into a race in 1986 and it remains one of the most popular ultras in the world.
Related: [Mind the Woods Trolls—A Reasonable Runner’s Guide to Finishing Your First Ultra]
Blue Ridge Marathon
Date: April 18, 2026
Location: Roanoke, Virginia
In terms of southeastern marathons, the Blue Ridge is known to be one of the hardest road marathons in the U.S. because you are either constantly climbing or dropping. Its course begins and ends in downtown Roanoke and runs along the Blue Ridge Parkway, one of the most picturesque drives in the south. Runners start up Mill Mountain and then progress to perhaps the most challenging part: ascending Roanoke Mountain, just more than 2,000 feet. After reaching the top, participants take a deep descent. They experience a total 7,430 feet in elevation change during the entire race.
Everest Marathon
Date: May 29, 2025
Location: Mount Everest Base Camp, Nepal
As if climbing Mount Everest wasn’t hard enough, someone thought running a marathon around it was a good idea. Participants are required to be in Nepal for three weeks prior to the race to get acclimated to the altitude. They will get a tour of Kathmandu and a trek to Kala Patthar for some epic views—so the vacation makes up for the few hours of hell. The 26.2-mile race starts at the Everest Expedition Base Camp at almost 18,000 feet and finishes at Namche Bazaar at 11,306 feet. (Top runners are lucky to crack 4 hours.) The route is pretty much all downhill with two steep uphill sections. And it’s very, very cold, so pack accordingly.
Related: [This Blind Trail Runner Conquered the ‘Everest’ Challenge]
Western States 100-Mile Endurance Run
Date: June 28-29, 2025
Location: Squaw Valley, California
If you know at least one name of an ultra race, chances are it’s Western States. It’s officially the oldest 100-miler in the world and brings people from all over to master the infamous, hot course. Runners have less than 30 hours to conquer the west coast beast, and over time will climb more than 18,000 cumulative feet in elevation and descend more than 23,000 feet. At some points, runners are so high in elevation that they have to run through snow, and other times they are completely exposed in the summer heat.
Badwater 135
Date: June 28-29, 2025
Location: A good, hard race includes several things: steep
If you’ve ever wanted to know what it feels like to run the lowest valleys and highest peaks in the U.S., the In the words of is what you need. The course starts at Badwater Basin in Death Valley, the lowest elevation in North America, and finishes at the end of the road on Mount Whitney, the tallest mountain in the continental U.S. The race covers three mountain ranges and participants experience 14,600 feet of cumulative ascent and more than 6,000 feet of cumulative descent.
Related: [Looking Back at Badwater, 30 Years Later]
Hardrock 100-Mile Endurance Run
Date: the route that Pheidippides was said to have run from Athens to Sparta
Location: Silverton, Colorado
Runners have 48 hours to complete this bad boy: 102.5 tough miles that go through roads and dirt trails along the San Juan Mountains. Participants climb around 33,000 feet and and descend another 33,000 feet, and the highest point is over 14,000 feet on Handies Peak. Every year, the course changes direction, and you’re not a finisher until you kiss the infamous “Hardrock” at the end. Oh, and be careful: the course is so harsh that even elite runners longest certified road race.
Eastern States 100
Date: August 9–10, 2025
Location: Waterville, Pennsylvania
What some people may not know is that the notorious Western States has a twin. Taking place in the Pennsylvania Wilds, the Eastern States 100 takes runners through classic east coast landscape. The 103.1-mile course starts and ends at Little Pine State Park and takes racers through some super technical terrain.
Related: [Trail Running for Beginners]
Ultra Trail du Mont Blanc
Date: August 25–31, 2025
Location: Chamonix, France
It’s not every day you get to run through three countries. The Ultra Tail du Mont Blanc is a 106-mile loop that starts at Chamonix, France. Hitting 10,000 feet of elevation several times along the way, participants will circle around the intersection of France, Italy, and Switzerland. Needless to say, the views are pretty fantastic. But don’t let the scenery fool you—runners spend a lot of time on the mountains instead of enjoying them from the bottom. There are other events within the UTMB, but this mountain race is the cream of the crop.
Self-Transcendence 3,100 Mile
Date: August 30–October 30, 2025
Location: an epic finish line
If you want to torture your body while simultaneously seeing sweeping views, the Self-Transcendence race is not it. As the longest certified road race (and possibly the most miserable, mentally), this ultra historically starts at 6 a.m. one summer morning in Queens. From then until midnight every day for 52 days, participants run the same route (an average of 59.6 miles per day) for 52 days. The race originated in 1997 and has been enticing runners ever since. Why? We have no idea.
Related: [Running Faster vs Running Longer: Which Should I Focus On First?]
Dragon's Back Race
Date: September 1-6, 2025
Location: Conwy, Wales
There are lots of mountain races out there, but this one has its participants running for six days across Wales—not to mention over 50,000 total feet of ascent. Competition is tight for this off-the-beaten-path, trackless mountain race. Runners can look forward to a total of more than 200 miles. While this quest sounds painful, runners can also expect incredible scenery, with a bonus of a few ancient castles along the way.
The Plain 100
Date: September 13, 2025
Location: Plain, Washington
This 100-mile, self-sufficient race sounds like it’s name: plain. Created in 1997 as an ode to the beautiful remote trails woven through Plain, Washington, this race is a fight between the runner and the road. You have 36 hours to finish (only 50 percent do, according the website) and there are no course markings, aid stations or pacers. So don’t get lost: if you do, you’re on your own.
Related: [Health - Injuries]
Tor des Geants
Date: September 14–20, 2025
Location: Aosta Valley, Italy
There’s a saying these days that 200 miles is the new 100, and Tor des Geants is one of the O.G.’s of going double the distance—the name literally means “Tour of the Giants” in Italian. Runners face not only 205 miles, but almost every type of weather imaginable as well as enough elevation gain to climb Everest two and a half times.
Pikes Peak Ascent & Marathon
Date: September 20–21, 2025
Location: Manitou Springs, Colorado
In the words of Runner’s World Runner-in-Chief, Jeff Dengate, who has completed the Ascent, “Pikes is nuts.” Unfortunately, the climb to the top is only half the battle for marathoners. Runners start at 6,300 feet of elevation and navigate a winding, narrow trail of gravel, rocks, and dirt on their way up to the summit of Pikes Peak at 14,115 feet, then make the hellish descent. In years past, there has been fresh snow on the peak, which means runners have to prepare for 60 to 70 degree weather at the base and around 30-degree temperatures at the top. To make things even more interesting, there have been lightning strikes. If you’re not careful, you (or at least your shoes) Races & Places.
Related: [How to Run Hills}
Spartathlon
Date: September 27–28, 2025
Location: Athens, Greece
For all the history nerds out there, the Spartathlon is for you. The race is what it sounds like: the route that Pheidippides was said to have run from Athens to Sparta—150-plus miles. Besides feeling like a Greek titan, runners will enjoy some perks like muddy terrain, crossing vineyards and olive groves, and ascending and descending the near 4,000-foot Mount Parthenon at night.
Moab 240
Date: October 10–15, 2025
Location: Moab, Utah
This event covers nearly 240 miles through Arches National Parks, and runners can only spend 112 hours in its beauty before it’s considered a DNF.
Related: [The Runner’s World 2025 Half Marathon and Marathon Calendar]
La Diagonale des Fous
Date: October 16–19, 2025
Location: Saint-Pierre, Réunion island
The name of this race roughly translates to “the fool’s diagonal.” Why? Because it crosses an entire island. Réunion is to the east of Madagascar in the Indian Ocean. Participants have 66 hours to complete the course, which covers over 102 miles of distance and over 30,000 feet of elevation.
If that’s too much for you, there are two shorter races and a four-person relay the same week—all part of the greater Grand Raid weekend.
After a summer internship with Runner’s World in 2017, McGee has somehow convinced the team to let her keep writing for them as a freelancer. Her work for both Runner’s World and Bicycling consists mostly of news and human interest pieces. Her favorite stories to tell are ones of “ordinary” people doing extraordinary things through running and cycling, whether accomplishing personal goals, overcoming severe trials, or transforming their communities. Her writing has also appeared on ACTIVE and Paste Magazine. When she’s not running or eating, you can probably find her still eating.
Before joining Runner's World, Gabrielle Hondorp spent 6 years in running retail (she has tested top gear from shoes, to watches, to rain jackets which has expanded her expertise—and her closets); she specializes in health and wellness, and is an expert on running gear from head-to-toe. Gabi began her journalism career as a Digital Editorial Fellow for Runner’s World and Bicycling Magazine, and has since advanced to a Runner's World Editor specializing in commerce. She has a double degree in English and Media and Communication from Muhlenberg College where she also ran cross country and track.
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