An ultramarathon is a footrace longer than the traditional marathon distance of . The sport of running ultramarathons is called ultra running or ultra distance running.
Various distances, surfaces, and formats are raced competitively. The shortest common ultramarathon is , and is typically the longest course distance raced in under 24 hours, but there are also longer multi-day races commonly held as 48 hours, , or more, sometimes raced in stages with breaks for sleep.
The oldest and largest ultramarathons are held on roads, including the Comrades Marathon (more than 10,000 finishers annually) and Two Oceans Marathon (more than 6,000 finishers annually). Many ultramarathons have historical significance, including the Spartathlon, based on the 246 km run of Greek messenger Pheidippides from Athens to Sparta during the Battle of Marathon in a day and a half to seek aid against the Persians.
Ultra running World Championships are held by the International Association of Ultrarunners (IAU) for 50 km, 100 km and 24 hours. The Global Organization of Multi-Day Ultramarathoners (GOMU) holds World Championships for 48 hours and six days. World records are ratified and recognized by World Athletics (50 km and 100 km), the IAU (50 km up to six days), and by GOMU (48 hours up to 5000 km).
Ultramarathons also overlap with the sports of trail running and mountain running. Some races are among the oldest and most prestigious events, especially in North America. The oldest and also the largest trail race is the SainteLyon in France (more than 5,000 finishers annually). Many ultramarathon organizers are members of the International Trail Running Association (ITRA), an organization that evaluates the difficulty of specific ultramarathon routes according to a number of criteria, such as the distance, the cumulative elevation gain, and the number of loops and stages.
Overview There are two main types of ultramarathon events: those that cover a specified distance or route, and those that last for a predetermined period (with the winner covering the most distance in that time). Outliers are events like Backyard ultras which do not have a predetermined distance or time limit. The most common distances are , 50 miles (80.47 km), , , and continue up to the longest certified race distance of 3100 miles. Timed events range from 6, 12, and 24 hours to 3, 6, and 10 days (known as multiday races). Timed events are generally run on a track or a short road course, often one mile (1.6 km) or less.
The format of ultramarathons and the courses vary, ranging from single loops (some as short as a track),If the loop is less than , run direction changes every 2–4 (sometimes 6) hours [Citation Needed~~~~Mark Halsey] to point-to-point road or trail races, to cross-country rogaines. Many ultramarathons have significant obstacles, such as inclement weather, elevation change, or rugged terrain. Usually, there are aid stations, whether every lap of a track, small road or trail loop courses, or extending up to perhaps , where runners can replenish food and drink or take a short break.
There are some self-supported ultramarathon stage races in which each competitor has to carry all their supplies including food to survive the length of the race, typically a week long. The Marathon des Sables 6-day stage race in Morocco and the Grand to Grand Ultra in the U.S. are examples. Free community events such as Fat Ass races may also require competitors to bring their own supplies, but as a consequence of the race having minimal formal organisation, rather than as part of the challenge.
The International Association of Ultrarunners (IAU) organises the World Championships for various ultramarathon distances, including , , 24 hours, and ultra trail running, which are also recognized by World Athletics. Many countries around the world have their own ultrarunning organizations, often the national athletics federation of the country, or are sanctioned by such national athletics organizations.
50-kilometer and 100-kilometer races are recognized as World Records by World Athletics, the world governing body of track and field. The International Association of Ultrarunners recognizes IAU World Records for 50-kilometers, 100-kilometers, 6 hours, 12 hours, 100 miles, 24 hours, 48 hours, and 6 days.
There are ultramarathon racewalking events that are usually 50 km, although 100 km and 100-mile (160 km) "Centurion" races are also organized. Furthermore, the non-competitive International Marching League event Nijmegen Four Days March has a regulation distance of 4 × 50 km over four days for those aged 19 to 49.
In 2021, concerns were raised about planning and medical care available for ultramarathons in China, after 21 racers died from hypothermia while competing in an ultramarathon in the Yellow River Stone Forest. The government later announced a ban on "extreme" competitions.
In August 2023, a partnership between Ultra-Trail du Mont-Blanc (UTMB) and Ironman Triathlon was announced and the new formation of the UTMB World Series, an ultra-distance circuit that culminates with UTMB held in August. Concerns have been raised about rising entry fees, homogenization of racing experiences, and bulldozing of smaller events.
IAU World Record and World Best performances Until 2014, the IAU maintained lists of the world best performances on different surfaces (road, track, and indoor). Starting in 2015, the distinction between the surfaces was removed and the records were combined into a single category. Some governing bodies continue to keep separate ultramarathon track and road records for their jurisdictions.
Starting in January 2022, the IAU began to recognize and ratify performances as IAU World Records. World Athletics also began to ratify the 50k distance as a World Record for both mixed and women, respectively, along with 100k. The events considered IAU World Records are: 6, 12, 24, and 48 hours along with 50 and 100 miles. Records in the 6 day event are called World Best Performances by the IAU.
Performances exceeding the current IAU records but which have not yet been ratified include the following:
Ivan Zaborsky ran 1047.554 km in six days in Vallon Pont d'Arc, France, finishing on 4 May 2025. However, he broke a rule by displaying the Russian flag instead of following the regulations for neutral athletes. Megan Eckert ran 970.685 km in six days at the same race in Vallon Pont d'Arc in 2025, breaking the six-day women’s world record. Sibusiso Kubheka ran 100 km in 5:59:20 in August 2025 but the performance was not eligible to be a world record due to the footwear not satisfying competition requirements, among other reasons. Caitriona Jennings ran the Tunnel Hill 100 Mile race in 12:37:04 in November 2025. Ashley Paulson ran 100 miles in 12:19:34 at the Jackpot 100 Mile in February 2026. Satu Lipiäinen ran 85.712 km in six hours at the Kokkola Ultra Run in May 2026. In September 2026 Megan Eckert won the Global Organization of Multi-Day Ultramarathoners Six-Day World Championship with a run of 636.482 miles; this surpassed the six-day women’s world record and the six-day American men’s record. The IAU World Records and World Best Performances as of May 2026 are as follows.
Men EventRecordAthleteDatePlace50 km2:38:438 October 2022 San Francisco, US50 miles4:48:2111 November 2023 Vienna, IL, US100 km6:05:3514 May 2023 Vilnius, Lithuania100 miles10:51:397 January 2022 Tel Aviv, Israel6 hours98.496 km23 April 2022 Bedford, UK12 hours177.410 km7 January 2022 Tel Aviv, Israel24 hours319.614 km17 September 2022 Verona, Italy48 hours485.099 km30 May–1 Jun 2025 Pabianice, Poland6 days1045.519 km5–11 September 2024 Balatonfüred, Hungary
Women EventRecordAthleteDatePlace50 km2:59:5413 April 2021 Dorena, Oregon, United States50 miles5:18:579 November 2025 Vienna, IL, US100 km6:33:1125 June 2000 Yubetsu-Saroma-Tokoro, Japan100 miles12:42:4011 November 2017 Vienna, IL, US6 hours85.492 km11 March 2017 Münster, Germany12 hours153.600 km20 May 2023 Kokkola, Finland24 hours278.621 km18 October 2025 Albi, France48 hours436.371 km30 May–1 Jun 2025 Pabianice, Poland6 days928.577 km31 Aug–10 Sep 2025 Aabybro, Denmark
Former events Until 2021, the IAU also kept records for 1000 km and 1000 miles. The final records were:
Men EventRecordAthleteDatePlace1000 km5d 16:17:0026 November–2 December 1984 Colac, Australia1000 miles10d 10:30:3620–30 May 1988 New York City, US
Women EventRecordAthleteDatePlace1000 km7d 16:08:3729 September-6 October 2002 New York City, US1000 miles12d 14:38:4016–28 October 1991 New York City, US
IAU World Championships There are four IAU World Championships: the IAU 100 km World Championships, IAU 50 km World Championships, IAU 24 Hour World Championship, and the IAU Trail World Championships.
Ultramarathons by regions
Ultramarathons are run around the world with more than 600,000 people completing them every year.
Africa South Africa hosts a number of notable ultra marathon events. On road: the world's oldest and largest ultramarathon, the Comrades Marathon. Approximately 12,000 runners complete the Comrades each year, out of approximately 17,000 who start, with 23,961 competing in 2000. The Two Oceans Marathon in Cape Town in the southern autumn attracts approximately 11,000 runners. The Washie 100 Miler is Africa's oldest 100 mile road race, held in the Eastern Cape since 1977, running from Cathcart to East London. The Grand Raid de la Réunion is held annually on Réunion in October, crossing the island over with an altitude gain of . This race attracts 2,350 competitors, with 1,000 runners from overseas. The Marathon des Sables is a 6-day stage race which covers through the Sahara desert in Morocco. The Spanish Canary Islands off the African coast are the location of some prestigious ultramarathons, including the 46-mile Transvulcania.
Asia Ultrarunning has become popular in Asia, and countries such as Japan, Taiwan, and South Korea have hosted IAU World Championships.
In Israel, two major ultramarathon races are Mount to Valley relay race, over 215 km, from the hills of the Upper Galilee to the Jezreel Valley; and the Valley Circle race in the Jezreel valley, containing several distances, including 160 km and 200 km. India's first ultra-marathon, the Bangalore Ultra, was held in 2007. Since 2010, the Indian Himalayas have hosted La Ultra – The High, a 333 km course crossing Khardung La, touted to be the world's highest motorable mountain pass. Japan had its first 100 km event in 1987 as Lake Saroma Ultramarathon and hosted the IAU 100 km World Championship in 1994 (Lake Saroma), 1998 (River Shimanto) and 2005 (Lake Saroma). Japan hosts more than 50 ultramarathon events throughout the year, including the Trans Japan Alps Race (TJAR) ( with more than cumulative altitude gain crossing Japan Alps, crossing Japan's mainland from Japan Sea to Pacific Ocean in 7 days),NHK team, 激走! 日本アルプス大縦断 密着、トランスジャパンアルプスレース富山~静岡415km, 26 April 2013, Hasetsune cup ( in steep foggy mountains)RUNTRAIL editors, RUN+TRAIL vol.2 トレイルランレースをはじめよう ハセツネ/UTMF完走法 (SAN-EI MOOK),22 Aug 2012, and the Ultra-Trail Mt. Fuji ( loop around World Heritage Mount Fuji with a cumulative altitude gain of about ). The Gobi March in northwest China was China's first ultramarathon, first staged in 2003. The Gobi March is part of the 4 Deserts Race Series. Hong Kong Four Trails Ultra Challenge is a 298 km-long uninterrupted race, the first ultramarathon-class race in Hong Kong.
Oceania, Australia, and New Zealand Australia and New Zealand are hosts to some 100 organized ultramarathons each year. Additionally, a handful of runners have run the entire length of New Zealand, a distance of around .