The DNF Files: 2025 Ironman World Championship Kona

Lucy Charles-Barclay (GBR)

As Lucy Charles-Barclay ascended Palani Road before heading out onto the desolate highway, she gave Taylor Knibb a pat on the back and made the pass, reclaiming the lead she had lost on the bike course after being overtaken by Knibb and serving a one-minute unintentional littering penalty. At that moment, as she began to open up a gap on the highway, it looked as though Charles-Barclay was on her way to regaining her world title.

However, one aid station after another, her race began to unravel. A slow walk through the first showed the early warning signs, allowing Knibb to catch back up. Yet, bravely, Charles-Barclay didn’t let her get away at first, attempting to match Knibb stride for stride. But at the next station, she slowed even more, her stride faltered, and her composure slipped away. Knibb pulled ahead up the road.

Soon after, it became clear that Charles-Barclay was in serious trouble. She staggered heavily at an aid station as a volunteer tried to cool her with ice. Unfortunately, it was too late — her husband, Reece Barclay, decided in the Energy Lab to pull her from the course.

In an Instagram post shared afterward, Reece wrote, “We came close to a line you never want to cross. For me, as her husband, it was the easiest call I’ll ever make.”

Some may have questioned the decision, believing Lucy should have been allowed to decide for herself. Yet Lucy later shared her own perspective, writing, “I’m endlessly grateful for the love and care my husband showed in stepping in and taking me off the course.”

Taylor Knibb (USA)

Like Charles-Barclay, Knibb is coached by multiple Ironman World Championship-winning coach Dan Lorang. Knibb’s race looked set to deliver her first world title – and another for him – as she regained the lead while Charles-Barclay was suffering. She looked strong, paced her run steadily, and appeared to have learned from her experience racing in Kona in 2023, where she lost momentum on the run and eventually finished fourth overall.

With just three miles to go, Knibb held more than a two-minute lead over Løvseth and five minutes over Matthews. The math suggested it was almost impossible for her not to win. Even at the finish line, the announcers were preparing the crowd to welcome their new champion.

But reminiscent of Charles-Barclay’s recent collapse, Knibb began to walk at an aid station, then staggered through the next, before finally wobbling to the ground on the last stretch of highway before heading back into town. Like Charles-Barclay, the combination of heat, humidity, and the sheer toll of truly racing an Ironman from start to finish proved too much for her body to handle. And yet, like Lucy, her mind desperately wanted to continue – strong enough to ignore every warning sign – until her body ultimately had no choice but to shut down.

Incredibly, despite the heartbreak of losing in such tragic fashion, she shared after the race that she “wouldn’t change a thing.” and is already planning on returning to the island for attempt number three. “I’m not sure what the rest of the season looks like anymore. But I hope to be back and have another go next year on October 10th.”

Chelsea Sodaro (USA)

2022 Ironman World Champion Chelsea Sodaro had experienced a rocky start to the year, missing out on Ironman Texas due to illness. However, two strong 70.3 performances and a last-minute qualification for Kona at Ironman Kalmar in August meant her season was trending back in the right direction. She told us ahead of the race that she was even entering Kona feeling “the best I’ve ever been.”

And it started exactly as she would have hoped – a dream swim that placed her in the front pack, followed by a fast transition that had her leading the chase to Charles-Barclay. Unfortunately, that’s where the good momentum ended and the problems began. According to the commentary later in the race, Sodaro had begun throwing up shortly after the swim.

Amazingly, she pressed on as long as she could – valiantly continuing the bike leg, further than most of us could even imagine if we were in the same shoes. At the time of writing, the exact cause of her illness remains unclear, perhaps nutrition issues or ingesting saltwater during the swim, but one thing is certain: Sodaro is determined to return stronger and show the form she has been seeing in training with coach Neal Henderson, saying, “I loved every moment of preparing for this race. Not done yet.”

Justine Mathieux (FRA)

29-year-old French athlete Justine Mathieux arrived in Kona on the back of one of the best seasons of her career, having earned multiple podiums, a fifth-place finish at Challenge Roth, and even a T100 wildcard to race in Spain in the lead-up to the World Championship.

However, as is often the case at this time of year, a heavy race schedule can start to take its toll — and it seems that may have been true for Mathieux, as she shared on her Instagram. Like several others on this list, her main issues appeared to stem from the swim, where she reportedly swallowed multiple mouthfuls of salt water. That led to severe stomach problems on the bike, and eventually, as she put it, her legs “just gave out,” forcing her to stop.

Still, Mathieux remains determined to return and “tame” Kona in 2026 – especially after also not finishing in 2023, despite placing 20th in her debut appearance in 2022.

Lotte Wilms (NED)

A few weeks before race day, Lotte Wilms began suffering from bursitis in her hip, according to a Dutch triathlon website.

This isn’t uncommon for top triathletes in the final stretch before Kona, when training loads are at their highest and the margins between fitness and injury grow razor-thin. Many still choose to push through, risking it all for the potential reward on race day. After all, it’s not just a big day for the athletes — it’s also for their sponsors, supporters, and everyone behind the scenes. There’s often more on the line than just the finish line itself. For Wilms, she believed it would be manageable and, according to the report, decided not to share what she was dealing with.

She started with a typically strong swim. But midway through the bike, the bursitis flared up, compounded by rising heat stress. By the time she reached T2, the pain and overheating had become too much, and she ultimately made the difficult decision to pull out of the race.

Rachel Olsen (USA)

Similar to Mathieux and Sodaro, it was an unfortunate experience for Rachel Olsen in her first Ironman World Championship. She began vomiting after the swim, yet somehow continued for the next three hours, despite continually throwing up. Though she considered withdrawing multiple times, she persevered with the hope to “keep trying if anything would work or I would feel better.”

She pushed on into the run, partly in thanks because of a rule she shares with her partner, pro triathlete Andre Lopes, where they don’t wait for each other in transition – presumably a practical measure to avoid making a more comfortable early decision to quit that they might regret later. She continued as far as she could, covering a couple of miles before the physical and mental toll became too great and she was ultimately forced to pull out of the race.

Rebecca Anderbury (GBR)

Perhaps an unknown name to many, Anderbury has been turning heads in just her third professional season after coming through the Zwift Tri Academy. At Ironman 70.3 Swansea, a Pro Series race with a talented field, her bike split was just 32 seconds behind fellow Brit Matthews, and she backed it up with a strong run to take second. She followed that with her first 70.3 win in Poland, posting the fastest bike split by four minutes.

Having raced Kona as an age-grouper, Anderbury had experience on the island, but a pre-race headache, likely from early-start nerves, quickly worsened. By the bike, her eye began twitching – signaling to her a migraine – and she was forced to abandon the race on the run.

The part-time pharmacist remained upbeat, posting on Instagram, “I’ll reflect and learn and come back with a new perspective.”

Penny Slater (AUS)

After quitting her job as a high school teacher in 2022 to focus fully on triathlon, Penny Slater has steadily risen in the sport – finishing 13th in Kona in 2023, and in 2024, she finished second at Ironman Texas and 7th in Nice. Recently, however, her journey has been more of a rollercoaster, as she suffered two bone stress injuries in her femurs over 18 months – something she attributes to the long-term effects of RED-S, a subject she now studies as a PhD candidate with two papers under review.

After a promising third-place finish at 70.3 Sunshine Coast leading up to Kona, it seemed as if things were back on track, but the race went far from what she is capable of. Slater dropped out after the bike, sharing the heartbreak of not finishing the most important race of the year for the world’s best long-distance athletes: “It’s hard to put into words what this race means to us athletes and the triathlon community, and to not perform or even finish is honestly devastating.”

Marta Sanchez (ESP)

After racing a staggering 13 times in 2024, including a sixth-place finish at the World Championships in Nice, and following some arguably career-best Ironman performances in 2025, Marta Sanchez was a shoe-in candidate for a top-10 result in Kona – if not higher. And coming into the race after a block of altitude training in Sierra Nevada, where the Norwegian men are known to train, Sanchez was set to take advantage of the sea-level conditions in Kona.

The race began perfectly: she was sixth out of the water and stayed in contention with the front of the pack throughout the bike. On the run, she remained in the mix, even overtaking Holly Lawrence (GBR) into eighth place at the halfway point of the marathon. Shortly after, however, she was forced to pull out, citing that her “leg said enough” and that a “marathon was just too much.” She plans to share more details in an upcoming video, and updates will be provided when available.

Jeanne Collonge (FRA)

Remarkably, long-time French athlete Jeanne Collonge took on Kona after a punishing lead-up: she had raced Ironman Wales, one of the world’s toughest Ironmans, just three weeks earlier, and Embrun, another grueling event, only a month before that. With that schedule, even finishing would have been a notable achievement. Still, despite her determination and hope for a miracle, Collonge collapsed on the run at an aid station after 19K, having already struggled with dehydration at 80K on the bike.