|Highest governing body||World Athletics|
An ultramarathon, also called ultra distance or ultra running, is any footrace longer than the traditional marathon length of 42.195 kilometres (26 mi 385 yd).
There are two main types of ultramarathon events: those that cover a specified distance or route, and those that last for a predetermined period of time (with the winner covering the most distance in that time). The most common distances are 50 kilometres (31.07 mi), 100 kilometres (62.14 mi), 50 miles (80.47 km), and 100 miles (160.93 km), although many races have other distances. The 100 kilometer race is recognized as an official world record event by the International Association of Athletics Federations (IAAF), the world governing body of track and field.
Other ultramarathon races include double marathons, 24-hour races, and multiday races of 1,000 miles (1,600 km) or longer. The format of these events and the courses vary, ranging from single loops (some as short as a 400-metre (1,300 ft) track), to point-to-point road or trail races, to cross-country rogaines. Many ultramarathons, especially trail events, have significant obstacles, such as inclement weather, elevation change, or rugged terrain. Many of these races are run on dirt roads or mountain paths, though some are run on paved roads as well. Usually, there are aid stations, perhaps every 20 to 35 kilometres (12 to 22 mi), where runners can replenish food and drink supplies or take a short break.
Timed events range from 6, 12, and 24 hours to 3, 6, and 10 days (known as multi-day events). Timed events are generally run on a track or a short road course, often one mile (1.6 km) or less.
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. An example of this is the Grand to Grand Ultra in the USA.
The International Association of Ultrarunners (IAU) organises the World Championships for various ultramarathon distances, including 50 kilometres (31 mi), 100 kilometres (62 mi), 24 hours, and ultra trail running, which are also recognized by the IAAF. 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. World best performances for distances, times, and ages are tracked by the IAU.
Racewalking events 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 dozens of racers died from hypothermia, and at least one died of a heart attack; the government announced a ban on "extreme" competitions.
Until 2014, the IAU maintained lists of 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 own jurisdictions.
Patrycja Bereznowska recorded a distance of 401 km in 48 hours in 2018 but this performance does not appear to have been ratified so far by the IAU.
In August 2019, Zach Bitter ran 11:19:13 for 100 miles at the Pettit Center in Milwaukee and continued to reach 168.792 km in 12 hours. These will likely be confirmed as the new world bests once ratified.
In November 2020, CJ Albertson ran 50 km in 2:42:30 on a track in Clovis, California.
In April 2021, Desiree Linden ran 2:59:54 for 50 km in Oregon, which pending ratification will become a new world best.
On April 24, 2021, Aleksandr Sorokin ran 11:14:56 for 100 miles and 170.309 km for 12 hours in England, which pending ratification will both become new world bests.
In May 2021, Ketema Negasa set a time of 2:42:07 for 50 km and Irvette van Zyl ran the same distance in 3:04:23, both at the Nedbank Runified 50k Race in South Africa.
The IAU world bests are as follows.
|50 km||2:43:38||Thompson Magawana (RSA)||12 Apr 1988||Claremont, South Africa|
|100 km||6:09:14||Nao Kazami (JPN)||24 Jun 2018||Yubetsu-Saroma-Tokoro, Japan|
|100 miles||11:28:03||Oleg Kharitonov (RUS)||20 Oct 2002||London, United Kingdom|
|1000 km||5d 16:17:00||Yiannis Kouros (GRE)||26 Nov – 2 Dec 1984||Colac, Australia|
|1000 miles||10d 10:30:36||Yiannis Kouros (GRE)||20–30 May 1988||New York City, USA|
|6 hours||97.200 km||Donald Ritchie (GBR)||28 Oct 1978||London, United Kingdom|
|12 hours||163.785 km||Zach Bitter (USA)||14 Dec 2013||Phoenix, USA|
|24 hours||303.506 km||Yiannis Kouros (GRE)||4–5 Oct 1997||Adelaide, Australia|
|48 hours||473.495 km||Yiannis Kouros (GRE)||3–5 May 1996||Surgères, France|
|6 days||1036.800 km||Yiannis Kouros (AUS)[a]||20–26 Nov 2005||Colac, Australia|
|50 km||3:07:20||Alyson Dixon (GBR)||1 Sep 2019||Brașov, Romania|
|100 km||6:33:11||Tomoe Abe (JPN)||25 Jun 2000||Yubetsu-Saroma-Tokoro, Japan|
|100 miles||12:42:40||Camille Herron (USA)||11 Nov 2017||Vienna, IL, USA|
|1000 km||7d 16:08:37||Paula Mairer (AUT)||29 Sep-6 Oct 2002||New York City, USA|
|1000 miles||12d 14:38:40||Sandra Barwick (NZL)||16–28 Oct 1991||New York City, USA|
|6 hours||85.492 km||Nele Alder-Baerens (GER)||11 Mar 2017||Münster, Germany|
|12 hours||149.130 km||Camille Herron (USA)||9–10 Dec 2017||Phoenix, Arizona, USA|
|24 hours||270.116 km||Camille Herron (USA)||26–27 Oct 2019||Albi, France|
|48 hours||397.103 km||Sumie Inagaki (JPN)||21–23 May 2010||Surgères, France|
|6 days||883.631 km||Sandra Barwick (NZL)||18–24 Nov 1990||Campbelltown, Australia|
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.
The following is a selected list of world or national-record holding, or world-championship-winning, ultramarathon runners.
Ultra Marathons are run around the world with more than 70,000 people completing them every year.
Several ultra distance events are held in Africa.
Ultrarunning has become popular in Asia, and countries such as Japan, Taiwan, and South Korea have hosted IAU World Championships.
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 2,200 kilometres (1,400 mi).
In Australia, the Westfield Ultra Marathon was an annual race between Sydney and Melbourne contested between 1983 and 1991. Greek runner Yiannis Kouros won the event five times during that period. Australia is also the home of one of the oldest six-day races in the world, the Cliff Young Australian 6-day race, held in Colac, Victoria. The race is held on a 400-meter circuit at the Memorial Square in the centre of Colac, and has seen many close races since its inception in 1984. The 20th Cliff Young Australian six-day race was held between 20 and 26 November 2005. During that event, Kouros beat his existing world record six-day track mark and set a new mark of 1,036.851 kilometres (644.269 mi). The Coast to Kosciuszko inaugurated in 2004, is a 246-kilometre (153 mi) marathon from the coast to the top of Mount Kosciuszko, Australia's highest mountain.
Australia has seen a steep growth in ultrarunning events and participants in recent years. Many new races have come into inception, covering a range of ultramarathon distances from 50 km right through to multi-day events. The cornerstone of Australian Ultra events being such races as Ultra-Trail Australia 100, The Great North Walk Ultras, Surf Coast Century, Bogong to Hotham, Alpine Challenge, GC50 Run Festival, and the Cradle Mountain Run. The Australian Ultra Runners Association (AURA) has a comprehensive list and links of events and their respective results.
New Zealand's first ultramarathon, called the Kepler Challenge, was held on a 60 kilometres (37 mi) trail through Fiordland National Park. It has been running since 1988 and is one of the country's most popular races. New Zealand's Northburn 100 ultra mountain run is the first 100-mile (160 km) race through the Northburn Station. The Te Houtaewa Challenge has a 62 km race on ninety mile beach, Northland. The runners have to contend with rising tides and soft beach sand and the March race dates often means the race is run in the cyclone season. In 2014 the ultramarathon was postponed because of Cyclone Lucy. The Tarawera Ultramarathon is currently one of the most competitive ultras in New Zealand and part of the Ultra-Trail World Tour.
In December 2013 in Auckland, Kim Allan ran 500 km in 86 hours, 11 minutes, and 9 seconds, breaking the 486 kilometres (302 mi) women's record.
In April 2013, a Feilding man, Perry Newburn, set a new New Zealand record by running 483 kilometres (300 mi) without sleep at Feilding's Manfield Park.
Ultramarathon running in New Zealand has a national body: the New Zealand Ultrarunners Association.
New Caledonia Trail Festival has several annual Ultramarathon including the Ultra Trail New Caledonia 136 km / 6 000m D+ and the Endurance Shop Trail race 70 km / 3 000m D+ on Pentecost long Week end. The Trail des Cagous is another 60 km Ultramarathon held in April.
Papua New Guinea has the Kokoda Challenge Race, an annual 96 km endurance race held in late August that runs the length of the historic Kokoda Track.
Papua New Guinea also has the Great Kokoda Race, a multi-stage 96 km (3-day) race held in early July where competitors run or walk the length of the Kokoda Track.
In Europe, ultrarunning can trace its origins with early documentation of ultrarunners from Icelandic sagas, or ancient Greece from where the idea of the Marathon, and the Spartathlon comes. The history of ultrarunners and walkers in the UK from the Victorian Era has also been documented. The IAU hosts annual European Championships for the 50 km, 100 km and 24 hours. The European Ultramarathon Cup is an annual cup event covering some of the biggest Ultramarathon races in Europe. Also worth mentioning is the ultramarathon CajaMar Tenerife Bluetrail, the highest race in Spain and second in Europe, with the participation of several countries and great international repercussions.
There are over 300 ultramarathons held in Europe each year,. This includes the Harz Run in the Harz Mountains, the Irish Connemarathon, the British Spine Race and Welsh Dragon's Back Race which covers 315 km with 15,500m of height gain.
The UTMB, through France, Italy and Switzerland, has been considered the world's most competitive trail ultra. The other races in the UTMB festival, including the CCC, TDS and OCC, are also significant events in the ultrarunning calendar.
In 2021 the Megarace will be held. The Megarace will be the world's longest nonstop A-B trail race. The race is 1001 km and goes on trails through Germany, Czech Republic and Austria. The runners have 13 days and 15 hours to cover the distance. Due to Covid, 2021 the course will be modified to only go through Germany. The original course will be in 2022. 
Due to logistics and environmental concerns there are only a handful of ultramarathons held in Antarctica, and travel costs can mean entrance fees as high as $14,000. Ultramarathons in Antarctica include: The Last Desert, part of the 4 Deserts Race Series, a multi-stage footrace, and the Antarctic Ice Marathon – a marathon and 100-kilometer race.
There are several hundred ultramarathons held annually in North America. One of the best known is the Western States Endurance Run, the world's oldest 100-mile trail run. The race began unofficially in 1974, when local horseman Gordy Ainsleigh's horse for the 100-mile Tevis Cup horse race came up lame. He decided to travel the course on foot, finishing in 23 hours and 42 minutes.
One of the first documented ultramarathons in North America was held in 1926, and at the time was part of the Central American Games. Tomas Zafiro and Leoncio San Miguel, both Tarahumara Indians, ran 100 km from Pachuca to Mexico City in 9 hours and 37 minutes. At the time, the Mexican government petitioned to include a 100 km race in the 1928 Summer Olympics in Amsterdam; however, nothing came of these efforts.
In 1928, sports agent C. C. Pyle organized the first of two editions of the 3,455-mile-long Bunion Derby (the first went along U.S. Route 66 from Los Angeles to Chicago before heading toward New York; the 1929 Derby reversed the route). Neither the race nor the accompanying vaudeville show was a financial success.
Since 1997, runners have been competing in the Self-Transcendence 3100 Mile Race, which is billed as the longest official footrace in the world. They run 100 laps a day for up to 50 days around a single block in Queens, NY, for a total distance of 3,100 miles (5,000 km). The current recordholder is Ashprihanal Pekka Aalto, at 40 days 09:06:21 for a daily average of 76.776 miles (123.559 km) in 2015.
The latest Trans-American Footrace (2015) winner was Robert HP Young (Marathon Man UK), winning in a time of 482 hours and 10 minutes.
In April 2006, the American Ultrarunning Hall of Fame was established by the American Ultrarunning Association (AUA). Candidates for the Hall of Fame are chosen from the 'modern era' of American ultras, beginning with the New York Road Runners Club 30 Mile race held in 1958. The Inaugural inductees were Ted Corbitt, a former US Olympian, winner of the aforementioned race in 3:04:13, and co-founder of the Road Runners Club of America, and Sandra Kiddy, who began her ultra career at age 42 with a world record at 50 kilometers, 3:36:56, and who went on to set a number of US and world ultra records.
There are a small number of ultramarathons in South America, but participation in the sport is increasing. The Brazil 135 Ultramarathon is a single-stage race of 135 miles (217 km) with a 60-hour cutoff, held in Brazil. This is a Badwater "sister race". Several ultramarathons are held in Chile and with both local and international participation. Ultramarathons held in Chile include:
There are several ultramarathon races in Argentina.
La Mision has been going on for almost 15 years. There are different editions, one in Villa La Angostura in Patagonia with 3 distances. 110 km with cumulative altitude gain of about 4500m, 160 km with cumulative altitude gain of about 8000m and 200 km with cumulative altitude gain of about 9000m. There is other edition of the race (Short & Half) in Villa San Javier, Cordoba with 2 distances, 35k and 70k.
In April 2019 for the 1st time UTMB took place in Ushuaia (Ushuaia by UTMB) A very tough race facing the wild Patagonia weather with 4 different distances, 35k, 50k, 70k and 130k. The race brings together in one competition all the landscapes and geographies of the southern Andes (forests, rocky terrains, mountains, hills, glaciers, lakes, rivers and wetlands, among others) The race has a technical, non-stop format and is ruled by the principle of semi-autonomy.
Cerro Champaqui in Cordoba is the landscape of different races. Champa Ultra Race with 5 different distances, 8k / 18k / 26k / 42k and 62k. Also the UTACCH – Ultra Amanecer Comechingón with 7 different distances, 16k, 26k, 42k, and 4 ultras of 55k, 70k, 110k and 100 miles.
Ushuaia, at "the end of the world" also host Ultra Maratón Glaciar Martial with 3 different distances, 10k, 25k and 50k.
Many ultramarathon organizers are members of the International Trail Running Association (ITRA), an organization that promotes values, diversity, health and safety during races, as well as working to further the development of trail running and helps to coordinate between the national and international bodies with an interest in the sport. ITRA also 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. ITRA maintains a calendar of ultramarathon events.