Magnus Ditlev has described the sudden deterioration which ended his hopes of winning in Kona after leading the men’s IRONMAN World Championship deep into the marathon.

The Dane had looked in control, building a substantial advantage and taking time at aid stations to cool himself with ice and take on fluids.

But heading back from the Energy Lab, his race changed dramatically. Ditlev slowed, briefly recovered and then began walking as eventual champion Vincent Luis closed the gap.

Reflecting on Instagram, he explained that continuing to push eventually became neither possible nor responsible.

“Less than 30 min away from achieving my biggest dream,” he wrote.

‘A tough two years’

For Ditlev, the disappointment followed a preparation which had restored optimism after a difficult period.

“It’s been a tough two years for me dealing with sickness and disappointing results,” he explained.

“Over the past few months I felt that things were starting to turn around and I managed to prepare better and more meticulously for a race than I ever have.”

That preparation appeared to be paying off in Hawaii.

After emerging from the swim just over two minutes behind the leader, Ditlev moved through the field on the bike and eventually took control at the front.

He also showed composure when a bottle came loose, stopping to hand it to the race moto rather than leaving it on the course.

By T2, he had established a lead over Sam Laidlow and Matthew Marquardt, with Luis and Kristian Blummenfelt more than six minutes behind.

‘I thought I stayed within my limits’

Ditlev continued to look strong through much of the marathon.

As rivals changed positions behind him, he maintained a substantial cushion. At one stage, Luis and Blummenfelt were 4:33 back, while Ditlev was visibly investing time at aid stations in ice and hydration.

His account afterwards made clear that he had been trying to manage the conditions throughout.

“On race day I executed my pacing, cooling and nutrition plan to the best of my ability and thought I stayed within my limits on the bike and run,” he wrote.

“However heading back from the Energy Lab, the lights suddenly went out.”

The change was stark. Having looked so assured, Ditlev suddenly struggled to keep running.

He managed to get moving again after slowing at an aid station, but the recovery did not last. Luis continued to gain ground, cutting the deficit to 1:49 at the 20-mile point before eventually passing the walking leader.

“I did everything I could to keep going but in the end, it was neither possible nor responsible to keep pushing,” Ditlev explained.

Heartbreak, but hunger for another attempt

Luis went on to win, with Gustav Iden second and Marquardt third.

Ditlev opened his reflection by congratulating all three, paying tribute to Luis for winning what the Frenchman had approached as his final professional race.

And despite the disappointment, the experience of leading in Kona has strengthened his desire to return.

“Leading this race for so long into the marathon is the craziest experience I’ve ever had and definitely leaves me hungry for next year!”

For much of the day, Ditlev had put himself in position to realise his biggest ambition. The ending was brutal, but his reaction suggests that the belief rebuilt over recent months has survived it.