IT began as a dare, an examination of nerve and endurance to weed out the fit from the weak, deemed so tough that only those with military training could hope to survive unbowed. The quest to be crowned as the Ironman of Hawaii by swimming 2.4 miles in the swirling Pacific Ocean before cycling 112 miles around coastal roads battered by unpredictable winds and then, at the last, to run a full marathon under the baking sun.

27 years since its inception, the island of Kona will once more become the epicentre of triathlon this weekend. However its mythical attraction, for those of serious intent, also doubles as the sport’s world championships. “People have always talked to me about how magical it is,” David McNamee declares. “But I have to see it as any other race. I’ve stayed a little out of town, away from the hype, just to be more relaxed. If I can just focus on what I need to do, that will work. After the race, I’ll soak it all in.”

The 27-year-old from Irvine is not merely aiming to last the distance in a race typically won in a shade over eight hours. Having taken the radical decision last winter to abort his hopes of qualifying for the 2016 Olympic Games to opt for courses almost 10 times lengthier, he has thrown everything into mastering the art of endurance and endeavour in his quest to flourish far from home.

It was a move born of ambition but also realism. The ever-dominant Brownlee Brothers, bar injury, are certain selections for Rio next summer. Despite coming seventh at the Commonwealth Games, McNamee sensed he was the longest of shots to accompany them to Brazil. “Everything had gone flat,” he recalls. “I knew the Olympics wasn’t going to be a possibility for me.”

The Ironman circuit, predominately based in the United States, offered an alternative challenge but with strings unattached. The days of Lottery funding were at an end with the rookie propelled into a capitalist vortex from which only the strongest emerge enriched and acclaimed.

“You have to be independent and stand on your own two feet,” he says. “But that’s a relief. I can do what I feel I need to do. I don’t need to answer to anyone, other than me. If I fail, I fail. I don’t blame it on anyone else. And that’s one reason I’m enjoying it. The buck stops with me.”

Results provided immediate returns. A podium on his debut in South Africa. Victory in the UK leg of the series in Bolton, one place ahead of fellow Scot Fraser Cartmell who will also line up in Kona. “You’re always apprehensive,” McNamee affirms. “But even if Saturday doesn’t go well, I can look back on 2015 and be happy with what I’ve achieved. I’ve won a race. The transition’s gone smoother than I could have hoped for.”

Ensconced in Hawaii for the past 10 days, he will trust a level playing field lies ahead. Abruptly last Monday at 6am, the doorbell rang with a drug tester, despatched by UK Anti-Doping, lurking outside. Many of his foes, including a large Spanish contingent, are not similarly inconvenienced. Regimes vary wildly. It is a concern. “I’d be hesitant to say the sport is 100 per cent clean because the sad reality is it’s not going to be,” McNamee asserts. “Wherever there is glory on offer, people will take shortcuts.”

He will dare to dream that the transgressors will not thwart his chances of conquering the elements. With a perfect race, McNamee says, finishing in the top 10 will be a realistic goal, perhaps even more. “That’s my goal for the next couple of years, to get onto the podium. You could call it my Olympics. Because this is the biggest stage.”