A Brief History of the IAU 100k World Championships

A history of the IAU 100k World Championships.

By on December 4, 2024 | Comments

With the 32nd edition of the IAU 100k World Championships taking place this Saturday, December 7, 2024, in India, we use this article to look at the event’s history. We also throw in some interesting statistics about the championships, their history, and the 100-kilometer racing distance for the stats geeks.

From left to right, Great Britain’s Lee Grantham, the U.S.’s Geoff Burns, and Japan’s Takehiko Gyoba leading the 2018 IAU 100k World Championships early on. Photo: iRunFar/Bryon Powell

The Evolution of the IAU 100k World Championships

The first 100-kilometer race with International Association of Ultrarunners (IAU) championships status took place in 1987 in Belgium.

The 100k and 50k distances continue to be the two classic ultra-distances recognized by World Athletics as bone-fide records. This, of course, only applies to road races, where the distance can be accurately measured. The difficulty of measuring a trail course to the same accuracy is well known.

In its early days, with much help from Malcolm Campbell, Andy Milroy, and others, the IAU was instrumental in gaining recognition for ultra distances from World Athletics, or the International Amateur Athletic Federation (IAAF), as it was then known.

The pioneering exploits of runners of the caliber of Ann Trason, Don Ritchie, Eleanor Robinson, and others too numerous to mention here were brought to a wider audience via the organization. Although looked on by many as a fringe element of the athletics family, continued record-breaking performances at the distances pushed boundaries out and broke new ground. Ultra-distance running slowly but steadily gained acknowledgement and credibility.

Ann Trason - 1994 Western States 100

Ann Trason at the 1994 Western States 100. Trason was one of the pioneering ultrarunners who helped the sport to gain recognition. Photo: Western States 100

In the first few years, the IAU 100k World Championships were incorporated into an established event that included an open race. For the first edition in 1987 in Belgium, the results recorded 271 finishers — 255 men and only 16 women — where the Night of Flanders 100k was the host race. It is unclear how many of those runners represented national teams, but the results list 15 different countries — 10 from Europe, two from Africa, and three from North and Central America.

The Spaniard Domingo Catalan won the men’s race in 6:19:35, which is still one of the fastest championships wins. The pioneering Brit, Don Ritchie, who at the time had the fastest recorded 100k time at 6:10:21, set 10 years earlier in 1978, was second in 6:40:51. Agnes Eberle of Switzerland secured her nation’s only medal to date in the championships, when taking the women’s title in 8:01:33, ahead of France’s Monique Exbrayat in 8:19:48.

In the early years, the event moved around established races on the European circuit like the Winschoten 100k in The Netherlands, the 100k del Passatore in Italy, and the Night of Flanders 100k in Belgium, as well as one outing to the United States, when the Duluth 100k race hosted in Minnesota, in 1990.

The sixth edition, staged in Spain, appears to have been the first event restricted to championships entries from national federations, a format the IAU has continued. Some 21 countries appear in the results, with 56 men and 30 women competing.

The most recent IAU 100k World Championships in Germany, in 2022, featured 198 finishers — 89 women and 108 men — with 40 nations sending at least one runner. Some 20 countries sent a women’s team, and 21 countries a men’s team.

Of the 31 IAU 100k World Championships held to date, 25 have been staged in Europe, five in Asia, and one in the United States. They have all been road events. In 2003, an IAU 100k World Trophy was held as a track race in Italy, with a small field of 12 recorded finishers. It’s not included in the stats for this article.

The 2024 edition will be the first time India has hosted the IAU 100k World Championships, although the country hosted the 2023 IAU 50k World Championships as well as plenty of regional ultrarunning championships.

Floriane Hot and Caitriona Jennings - 2022 IAU 100k World Championships 1 and 3

Floriane Hot (right) and Caitriona Jennings (left), the 2022 IAU 100k World Championships first and third place women. This edition of the event took place in Berlin, Germany. Photo: Dinko Bažulić/Croatian ultra running team

Fastest Times at the IAU 100k World Championships

The last edition of the race in Germany in 2022 produced some of the fastest times ever seen in the IAU 100k World Championships. With the COVID-19 pandemic meaning there had been no championships for four years before that, since 2018, we can speculate if, in that time, carbon-plated super shoes were impacting 100k performances to the degree they are in other sub-ultra distances. The fact that six of the top 10 all-time men’s and six of the top 10 women’s times at IAU 100k World Championships events (as detailed in the tables below) were recorded in 2022 may speak to this!

The fastest male time from any of the championships was Haruki Okayama’s winning time of 6:12:10 from that year. The fastest women’s time from any championships belongs to Japan’s Norimi Sakurai from 2007, at 7:00:27, although the next three best women’s times are from the 2022 edition.

Haruki Okayama - 2022 IAU 100k World Champion

Japan’s Haruki Okayama (left) on his way to winning the 2022 IAU 100k World Championships, alongside teammate Nao Kazami, who finished sixth. Photo: Dinko Bažulić/Croatian ultra running team

We will soon know if this year’s race in India, where humidity may be a factor, will produce similarly fast times. The tables below show the top 10 fastest times in any edition of the IAU 100k World Championships men’s and women’s races.

Lowest Cumulative Team Scores

The team competitions are an integral element of all IAU world championships events. In the 100k team competition, up to six runners can be nominated by a country. The three fastest times contribute to the overall team score. The competition is always sharp, and as with many traditional team events, the results can come down to the third and final scorer in each team.

Men

The lowest cumulative men’s score recorded in the IAU 100k World Championships to date was by Japan at the 2022 edition. They recorded a combined time of 18:51:32. The three impressive Japanese counters were Haruki Okayama at 6:12:10, Junpei Yamaguchi at 6:17:10, and Nao Kazami at 6:21:43.

Women

The lowest cumulative women’s score was achieved by the United States, also in 2022. They recorded a combined time of 22:14:46. Their three counters were Courtney Olsen at 7:15:29, Anna Louden (née Kascius) at 7:24:41, and Nicole Monette at 7:34:36.

In the Context of 100k World Records

Interestingly, the fastest times men’s and women’s times in an IAU 100k World Championships are still lagging behind the overall world records for the distance. The men’s 100k world record is currently held by Lithuania’s Aleksandr Sorokin in 2023 at 6:05:35, and Japan’s Tomoe Abe set the women’s record in 2000, in a seemingly untouchable 6:33:11.

100 km World Record - May 2023 - Aleksandr Sorokin - Checking Pace

Aleksandr Sorokin checking his pace en route to his 100-kilometer world record at the 2023 World’s Fastest Run. Photo: NORD Security

In fact, for men, the top five 100k times on record were set outside of the IAU 100k World Championships. On the women’s side, Norimi Sakurai’s time from the 2007 IAU 100k World Championships sits in second place on the overall 100k record table for women.

In 2024, France’s Marie-Ange Brumelot ran an incredible 6:56:54 at the 100km à pied de Steenwerck. It’s not included on the record table below because, although the race course is certified, the event did not have an IAU label, which is required for IAU record-setting.

Closest Finishes

In the 31-year history of the IAU 100k World Championships, a number of finishes have been close — nearly down to the wire. We want to note that close, in 100k terms, can be a couple of minutes. Less than a minute is almost the equivalent of a sprint finish!

Men

On two occasions the men’s race for the win has been really close. In 1994, in Japan, Alexei Volgin of Russia headed off Poland’s Jaroslaw Janicki by 51 seconds, recording 6:22:43 to 6:23:34. The closest men’s finish to date was by Simon Pride of Great Britain, who recorded 6:24:05 in France, in 1999, just 21 seconds ahead of the host country’s Thierry Guichard in 6:24:26.

Women

The women have also had their share of sprints down the home straight. In 2005, Hiroko Syou of Japan beat the U.S.’s Anne Riddle (formerly Riddle Lundblad) by 41 seconds, 7:53:41 to 7:54:22.

Anne Riddle - 2005 IAU 100k World Championships

Anne Riddle taking second by a narrow margin at the 2005 IAU 100k World Championships. Photo courtesy of Anne Riddle.

Two British runners have gone even closer than that. The year 1993 in Belgium saw Carolyn Hunter-Rowe, in the first of her two championships victories, hold off Valentina Shatyaeva of Russia, 7:27:19 to 7:27:39, a mere 20 seconds.

But it was multiple-time UTMB champion Lizzy Hawker who really took things to the wire in 2006, in Korea. Hawker led for much of the race, but Italy’s Monica Carlin surged hard in the final 10k. Hawker managed to draw on something from somewhere to hang on. After almost seven and a half hours of continuous effort, she won by a slender four seconds over the fast-finishing Italian, 7:29:12 to 7:29:16.

IAU 100k World Championships Medal Table

In line with World Athletics policy, Russia hasn’t competed at championships events since 2015. However, their impact on the IAU 100k World Championships over the event’s deep history cannot be underestimated. Always keen attendees of the event from its early days, Russian athletes have won more individual podium medals than any other nation and have figured regularly in the team podiums as well, for both men and women.


We want to note that funding by national federations has often been an issue for many countries. While some federations have traditionally supported the event well, runners from other countries have to contribute in part or even in full, to get to the championships. The IAU, working with the event’s local organizers each time, does offer limited travel grants to help, but it remains commonplace that the better-funded nations are often found on the podiums.

Unlike the ever-growing trail scene, 100k road racing still offers scant reward. The majority of competitors at this distance are runners in other full-time work who love the sport. They may receive some small help in kind from sympathetic employers or free products along the way, but their primary motivation is seeking high-level competition and a life-defining day on their own running journeys.

Multiple Winners and Medalists

Men

In Konstantin Santalov, Russia has one of only two athletes to have won three IAU 100k world titles — in 1992, 1993, and 1996. This feat was equaled by the popular Italian, Giorgio Calcaterra, with his victories in 2008, 2011, and 2012. Five other male athletes have recorded two gold medals:

  • Domingo Catalan (Spain) – 1997 and 1998
  • Valmir Nunes (Brazil) – 1991 and 1995
  • Hideaki Yamauchi (Japan) – 2016 and 2018
  • Grigorii Murzin (Russia) – 1998 and 2005
  • Mario Fattore (Italy) – 2002 and 2003

Women 

To date, only the Russian Tatyana Zhirkova has achieved the hat trick of victories, in 2002, 2004, and 2008. Six women have won two titles each:

  • Ann Trason (U.S.) – 1988 and 1995
  • Eleanor Robinson (Great Britain) – 1990 and 1991
  • Valentina Shatyaeva (Russia) – 1994 and 1996
  • Norimi Sakurai (Japan) – 2003 and 2007
  • Carolyn Hunter-Rowe (Great Britain) – 1993 and 1998
  • Ellie Greenwood (Great Britain) – 2010 and 2014
Ellie Greenwood - 2014 IAU World 100k Championships - female winner

Ellie Greenwood taking the win at the 2014 IAU 100k World Championships. Photo: Adrian Stott

The IAU 100k World Championships is always eagerly awaited. In some ways, it is one for the purists. The lure of the trails may well be where the majority of ultrarunners head naturally, and no one can argue with that.

However, for many whose natural ability lies in the rhythm of reeling off the miles effortlessly, like clockwork, on tarmac, the classic 100k distance will always hold a special place, and, like the marathon, be a challenge well worth pursuing.

Call for Comments

  • Will you be following the IAU 100k World Championships this weekend?
  • What countries and individuals do you think will come out on top?
  • Want to add any more IAU 100k World Championships history or stats in the comments section?
Adrian Stott

Adrian Stott is a freelance writer based in Edinburgh, Scotland. A former international ultrarunner, he has been involved for several years with team management with the Great Britain team, and is a member of the Ultra Running Advisory Group (URAG) for the British Athletics Federation. He also blogs at Runnersaresmilers.com.