Roth and Frankfurt have a long history in the Ironman distance game. Roth was the site of Ironman Germany, known as Ironman Avia from 1988 to 1990 and as Quelle Ironman Germany from 1991 through 2001. After Ironman split from the Walchshofer family, the World Triathlon Corporation held their race as Ironman Germany in Frankfurt from 2001 through 2004, and as the Ironman European Championship in Frankfurt from 2005 to the present day. From 2002 to the present day, the Walchshofer family has run their race as Challenge Roth.

All told, Challenge Roth 2017 will be the 30th Ironman-distance race held in Roth – 14 as an Ironman, 16 as a Challenge race. The 2017 Ironman European Championship will be the 16th Ironman brand event held in Frankfurt.

Both races are among the most prestigious, well-attended, and richly rewarded Ironman-distance triathlons in the world. Spectator estimates (by local police) are approximately 250,000 for Roth (held in a smaller municipality) and 500,000 for Frankfurt (a large urban metropolis). Roth has a total prize purse of 75,000 Euros with 15,000 Euros going to the men’s and women’s winners. Frankfurt has a total purse of $150,000 with $30,000 going to the winners.

Since its inception as an Ironman event and its continuation in 2002 as a Challenge race, Roth is famed as the fastest Ironman-distance course in the world. In 1996, Lothar Leder became the first man to break the 8-hour mark at Ironman Germany in Roth. In 2016 Jan Frodeno set the men’s Ironman-distance record at 7:35:39 and Chrissie Wellington set the women’s Ironman-distance record at 8:18:13 in 2011.

In a rarity, Roth and Frankfurt will hold their events on the same day - Sunday morning. Timothy Carlson rates the fields below, subject to the usual last-minute withdrawals.

Challenge Roth

Women

Daniela Ryf, 30, Switzerland

Last year at Roth, Ryf came within 3:51 of Chrissie Wellington’s 2011 women’s Ironman-distance record time of 8:18:13. That time was set after Ryf withdrew two weeks before at Ironman Frankfurt due to hypothermia on the swim and made a last-minute entry at Roth. Not an ideal preparation – but with how close the Swiss two-time Ironman World Champion came to Wellington’s mark, it ignited anticipation for this year’s race.

Right now the Swiss star is halfway to matching Wellington’s 4 wins at Kona and has already knocked off Wellington’s Kona women’s race record time with an 8:46:46 winning time last year. With her two wins at Kona, two wins at the Ironman 70.3 Worlds and no last minute change of schedule, Ryf has become the feature attraction for the 28th running of this Ironman-distance classic – and the 17th time it has been run under the Challenge Family banner.

Wellington will be on hand to congratulate Ryf is she breaks the mark. But first Wellington will take part in a four-person celebrity mixed gender relay team.

Heather Wurtele, 37, Canada

While Ryf is a prohibitive favorite, Wurtele has a strong résumé and the Canadian can give the Swiss star a battle. Wurtele is a three-time Ironman 70.3 World Championship podium finisher – 3rd-2nd-3rd in 2014 through 2016 – a six-time Ironman winner and has 18 Ironman 70.3 victories to her credit.

Yvonne Van Vlerken, 38, Netherlands

The Dutch pocket rocket has broken the 9-hour mark a record 12 times with a personal record 8:43:07 set at Ironman Florida in 2013. Van Vlerken has held a front seat to history by finishing 2nd to Wellington at the 2008 Ironman World Championship and will be in the mix as Ryf attempts to break Wellington’s mark at Roth on Sunday. Van Vlerken is the only woman to hold the world record for both the half-Ironman distance (4:07:29 at 2006 Ironman 70.3 Antwerp) and the full Ironman distance (8:45:48 at 2008 Challenge Roth).

Laura Siddall, 36, Great Britain

Last year Siddall set a personal best of 8:51:59 for the Ironman-distance while placing 4th at Challenge Roth. Siddall has become a consistent performer at Ironman distance events with 2017 runner-up finishes at Challenge Melbourne and Ironman New Zealand.

Ruth Brennan Morrey, 41, USA

This late blooming former professional soccer player was 2nd at 2014 Ironman Chattanooga, 5th at 2015 Ironman Frankfurt and 4th at 2016 Ironman Arizona.

Men

Joe Skipper, 29, Great Britain

While Jan Frodeno was smashing the Ironman-distance world record with a 7:35:39 mark last year at Roth, Joe Skipper also broke 8 hours with a 7:56:23 runner-up finish and a sizzling fast, race-best 2:38:52 run.

Timo Bracht, 41, Germany

In his farewell appearance as a professional, Bracht is more than a sentimental favorite. His 9-time Ironman-distance career wins stretch from 2003 at Gerardmer to 2014 at Challenge Roth and include a still-standing race record at the 2011 edition of Ironman Lanzarote. His most recent Ironman podium was a 2nd place at Ironman Switzerland last year.

Bart Aernouts, 33, Belgium

This Belgian with a penchant for duathlon victories is coming on strong this year with a dominating win at Ironman Lanzarote; he also had a win at Ironman Nice in 2014.

Nils Frommhold, 31, Germany

This German comes armed with a 2015 win at Challenge Roth and strong 2017 performances including 2nd at Ironman South Africa and 3rd at the Ironman 70.3 European Championships at Elsinore, Denmark.

Terenzo Bozzone, 32, New Zealand

Bozzone jump started his career early with a still-standing Wildflower course record in 2006 and an Ironman 70.3 World Championship in 2008. Last year, Bozzone won Bahrain 70.3 and Ironman Western Australia, and took 4th at Ironman 70.3 Worlds.

Brad Kahlefeldt, 37, Australia

Long time ITU Olympic distance star Kahlefeldt - bronze at the 2005 and 2007 ITU World Championships, gold medalist at the 2006 Commonwealth Games, and two-time Olympian - has switched to long distances. Notably, Kahlefeldt took 3rd at 2015 Ironman Melbourne and 4th at 2016 Ironman Cairns.

Mainova Ironman European Championship Frankfurt

Men

Sebastian Kienle, 33, Germany

Kienle has by far the best résumé at Frankfurt: a 1st, 2nd, 3rd and 4th in 2014, 2016, 2013 and 2012 at the Ironman World Championship, two wins (2012 and 2013) and two 2nd places (2015 and 2016) at the Ironman 70.3 Worlds, two second places at Challenge Roth (2010 and 2011), and he is the defending champion at Ironman Frankfurt. So far this year, Kienle was 2nd to Lionel Sanders at Challenge – the Championship and 3rd at Ironman 70.3 St. George.

Patrick Lange, 30, Germany

This relative newcomer to the elite level in long distance triathlon broke through with a win last year at Ironman Texas. Next he stunned at fans at Kona by breaking Mark Allen’s 27-year-old Ironman World Championship run record with a 2:39:45 marathon on his way to taking the final spot on the podium of a 1-2-3 German sweep.

Andi Böcherer, 34, Germany

Böcherer has an Ironman-best time of 7:53:40 and took 2nd at Frankfurt and 5th at Kona last year. So far this year Böcherer finished 2nd at the Ironman 70.3 European Championship at Elsinore, Denmark.

Michael Raelert, 36, Germany

This two-time Ironman 70.3 World Champion (2009 and 2010) has yet to be at his best at the Ironman distance (2nd place at 2012 Ironman Regensburg and 7th at 2013 Ironman Frankfurt,) but has more than 20 titles at the 70.3 distance. After a year and half lost to rehab after a 2013 knee injury, the younger Raelert is back to his old speed and has a renewed ambition to match his older brother’s exploits at the Ironman distance.

Cyril Viennot, 35, France

This Frenchman is a consistent performer at the Ironman distance with a 5th and 6th at Kona (2014 and 2015). In 2016 he was 4th at Challenge Roth and 2nd at ITU long distance Worlds, and this year he took 3rd at Ironman New Zealand.

James Cunnama, 34, South Africa

In 2012, Cunnama won Challenge Roth in a time of 7:59:39. In 2013 he was 4th at Kona and 2nd at Challenge Roth. Last year he won Alpe d’Huez and Embrunman and took 2nd at Ironman France. So far this year Cunnama was 2nd at Ironman 70.3 South Africa.

Sylvain Sudrie, 35, France

Sudrie won the ITU long distance Worlds in 2010 and 2016.

Giulio Molinari, 29, Italy

Last year the Italian won Challenge Rimini and took 5th at Ironman Arizona. This year, Molinari took 8th in his Ironman debut in South Africa and won Challenge Rimini and Staffordshire 70.3. Molinari has won 9 Ironman 70.3 and middle distance triathlons.

Marko Albert, 38, Estonia

Albert took 2nd at Ironman New Zealand in 2013 and won it in 2014. Last year he was 3rd at Ironman South Africa and 4th at Ironman Frankfurt. In 2011 he was 3rd at Ironman Austria.

Bas Diederen, 37, Netherlands

Diederen won Ironman Maastricht in 2015, was 2nd at Ironman Mexico in 2012, and 3rd at Ironman Frankfurt in 2013. His Ironman PR is 8:05:36 at Frankfurt in 2015.

Women

Anja Beranek, 32, Germany

Without the absolute top-ranked players in the women’s field, Beranek is a talented favorite. In 2015 she won Challenge Roth and Ironman Wales, and last year she was 4th at the Ironman 70.3 European Championship in Wiesbaden and at Kona.

Lucy Charles, 23, Great Britain

While this former top swimmer is a newcomer to the top ranks of female Ironman competitors, Charles is coming on fast and strong. Last year she was 3rd at Ironman Lanzarote in well over 10 hours. This year is a different story: second at Challenge Gran Canaria, and a streak of three wins against increasingly harder competition – Challenge Lisboa, a dominating win at Ironman Lanzarote, and a 30,000 Euros top prize for a victory at Challenge – the Championship.

Sarah Crowley, 33, Australia

A great showing this year with wins at top ranked events – Bahrain 70.3 and the Ironman Asia-Pacific Championship at Cairns.

Diana Riesler, 32, Germany

Riesler is a 5-time Ironman winner with victories at Ironman Lanzarote, Ironman Vichy and Ironman Malaysia in 2016.

Corinne Abraham, 39, Great Britain

Abraham scored significant wins at 2013 Ironman Melbourne, 2014 Ironman Frankfurt, and 2015 Ironman Cozumel, as well as 2nd place finishes this year at Ironman Lanzarote and Ironman Austria. The question is: can she turn around a third major Ironman in 7 weeks?

Sonja Tajsich, 41, Germany

Tajsich is coming off a strong 2nd place 8:57:36 finish at Ironman Brazil, consistent with a 4th at 2012 Ironman World Championship and 4th at 2015 Ironman Frankfurt and 2015 Ironman Copenhagen.

Liz Lyles, 39, USA

Lyles keeps getting better as she nears 40 – 2nd at 2014 Ironman Frankfurt, 2nd at 2015 Ironman Brazil, 1st at 2016 Ironman Brazil, 1st at 2016 Ironman Wisconsin, two-time Wildflower long course champ, and 1st at 2017 Raleigh 70.3.

Alexandra Tondeur, 30, Belgium

Tondeur was runner-up at 2016 Ironman Lanzarote and 2016 Cannes International, and 1st at 2017 Ironman 70.3 Luxembourg.

Natascha Schmitt, 31, Germany

Schmitt placed 4th at Ironman Frankfurt last year.