The men’s IRONMAN World Championship returns to Kona on Saturday 10 October, with a formidable field preparing to chase triathlon’s most coveted full-distance title.

For the first time since 2019, the professional men and women will race on the same day in Hawaii. After the men contested last year’s championship in Nice, the lava fields, Queen K and Energy Lab are back at the centre of their season.

Unfortunately the defending champion Casper Stornes will be missing following his training crash, but four former champions remain: Gustav Iden, Kristian Blummenfelt, Sam Laidlow and Patrick Lange.

They face established Kona contenders and an intriguing group of newcomers, while the IRONMAN Pro Series will also be decided on Saturday. Winning the world title and winning the season-long crown could produce two different celebrations.

Here’s our guide to the men’s race, which brings together our full preview package and includes how to watch, the leading contenders and the battles to follow.

Date, start time and how to watch live

The professional men’s race starts at 06:20 local time in Kailua-Kona on Saturday 10 October, with the professional women following ten minutes later.

For viewers around the world, the men’s start time is:

• UK: 17:20 BST on Saturday.
• Central Europe: 18:20 CEST on Saturday.
• US East Coast: 12:20 EDT on Saturday.
• US West Coast: 09:20 PDT on Saturday.
• Sydney and Melbourne: 03:20 AEDT on Sunday.
• New Zealand: 05:20 NZDT on Sunday.

The race will be broadcast live and free on IRONMAN’s YouTube channel and the IRONMAN Pro Series website, with access available internationally, including the United States and Canada.

There is also a YouTube ‘Mosaic multiview’ with four live feeds on one screen, which is available to watch on your smart TV.

Additional regional coverage includes DAZN, L’Équipe in France, HR in Germany and RTVE Play in Spain.

The IRONMAN Tracker app is also a useful companion to the broadcast, allowing you to follow individual athletes and their progress through the timing checkpoints.

Who is racing – and who is missing?

Iden wears M2, Blummenfelt M3, Van Riel M4, Laidlow M5 and Lange M6, with Schomburg assigned M7.

Other major names include Matthew Marquardt, Menno Koolhaas, Rudy von Berg, Sam Long and Magnus Ditlev, alongside French newcomers – in Kona terms – Vincent Luis and Pierre Le Corre.

The most significant absentee is Stornes. The reigning champion was ruled out after a training crash left him with a broken collarbone and a fracture in his lower back.

Arthur Horseau and Rasmus Svenningsson have also withdrawn while Jelle Geens and Lionel Sanders are among the notable names who did not secure places.

Our full men’s start list and bib-number guide provides plenty more detail and includes the latest withdrawal updates.

Podium predictions: Who are the favourites?

Our Daily Split team’s leading trio is Blummenfelt, Laidlow and Iden.

Blummenfelt’s season gives him a strong case, while Laidlow’s attacking approach will likely again make him a central figure on the bike. Iden brings the experience of winning here in 2022 and encouraging recent form.

Schomburg, Van Riel and Marquardt head the next group of challengers. Ditlev, Koolhaas and Lange remain dangerous, with Trevor Foley our wildcard. This time last year we highlighted Solveig Løvseth as an outsider to make a splash at Kona and we are similarly confident about Foley in the men’s race this time around.

That is the brief verdict — our full men’s power rankings explain the selection and assess all ten contenders.

Which Kona newcomers could make an impact?

Van Riel and Schomburg could influence the race from its opening stages, bringing the swimming ability and aggressive instincts to put pressure on their rivals.

Van Riel already has World Championship experience from Nice, but his first Kona build-up has been disrupted by illness. Schomburg arrives after a breakthrough full-distance season and could be particularly dangerous if the race becomes an attacking contest.

Luis’s first Kona appearance could also be his last, with the short-course legend contemplating retirement after this season. Le Corre has built his year around this race, while Frederic Funk’s debut offers another test of his transition to full-distance racing.

Jamie Riddle also deserves attention after finishing tenth in Nice last year.

Read more about those athletes in our Kona debutants to watch feature.

What is the Kona course like?

The race begins with a 3.8km ocean swim in Kailua Bay, starting and finishing beside Kailua Pier.

The 180km bike takes athletes out through the lava fields on the Queen Kaʻahumanu Highway towards the turnaround at Hawi. Rolling terrain, exposed roads and potentially strong crosswinds make pacing and bike handling crucial.

The 42.2km marathon starts along Aliʻi Drive before climbing Palani Road and heading onto the Queen K. The trip into the Energy Lab precedes the return towards town and the finish on Aliʻi Drive.

The route is familiar, but heat, humidity and wind can transform how it races. Athletes need to preserve enough energy to compete late in the marathon, rather than simply reach it in a good position.

Our detailed Kona course guide covers the swim, bike and run, with the key sections to watch.

What is at stake in the IRONMAN Pro Series?

Kona is the final counting race of the 2026 Pro Series, so the season-long titles will also be settled on Saturday.

The Series champion earns $200,000, exceeding the $125,000 first prize for winning Kona. Claiming both would therefore deliver $325,000 from those two prizes alone.

Stornes’ withdrawal has changed the men’s contest. Once counting-score adjustments are made, Van Riel holds the advantage over Schomburg, Blummenfelt and Iden.

Assuming their Kona scores count, Blummenfelt needs to finish more than 4:08 ahead of Van Riel and more than 54 seconds ahead of Schomburg to move above both.

Van Riel could therefore finish behind a rival in the race and still win the Series. The margins between contenders matter as much as their finishing positions.

Our full Pro Series permutations guide explains the calculations and gaps to follow.

How it could play out

The opening swim: Several leading contenders have the speed to make the swim demanding and it sounds like the infamous WhatsApp group is back in action with those on it including the likes of Riddle, Schomburg, Luis and Koolhaas. If they are all willing to take turns up front then it’s going to make it harder for everyone and any meaningful split could shape the groups that form on the bike and force others into an early chase. Remember though, the swim is only about 10% of the race in time terms.

Our fastest swim prediction: Menno Koolhaas.

The bike’s balance of aggression and restraint: Laidlow, Schomburg and Van Riel have the potential to drive the race but a huge field of world-leading athletes make it less likely for any of the big contenders to be isolated in the way they might be at a Challenge Roth for example. The question is who can apply pressure while preserving enough for the marathon – and how the likes of Blummenfelt and Iden respond.

Our fastest bike prediction: Sam Laidlow.

The marathon and the Series clock: Kona can change dramatically late in the day – the last men’s race in Kona saw Lange sluice through the field from way back. Alongside the world-title battle, keep watching the gaps between Van Riel, Schomburg, Blummenfelt and Iden. Crossing the line first will settle the most important battle; the stopwatch could decide the other.

Our fastest run prediction: Kristian Blummenfelt.