Ironman triathlons are, by any measure, a frightful prospect.
The race features a 3.86 kilometre swim, a180km bike ride and finishes off with a marathon (42.20km) run.
It is one of, if not the toughest single-day race in sport.
This weekend, for the first time since 2019, the Ironman World Championship returns to Kailua-Kona in Hawai'i, the race's spiritual home.
If an Ironman is tough, competing in Kona is as daunting as it comes, yet it is also what triathletes everywhere aspire to, from the weekend warriors to the world's elite pro athletes.
But what goes into competing in such an arduous race?
Aussie success
Since Greg Welch became the first Australian winner in 1994, Australian athletes have enjoyed considerable success in Hawai'i.
During a stunning eight-year run of consecutive podium finishes, Chris McCormack (2007 and 2009), Craig Alexander (2008, 2009 and 2011) and Pete Jacobs (2012) combined for six consecutive race victories.
In the women's race, Michellie Jones led the charge for the Aussies with her 2006 victory, which came hot on the heels of her second-placed finish in 2005.
Kate Major also podiumed in that period, finishing third three times, in 2004, 2005 and 2007.
Her success was followed by Mirinda Carfrae, who won a trio of titles in 2010, 2013 and 2014, finished second a further three times (2009, 2011 and 2016) and third once (2012), making her Australia's most successful triathlete at the World Championships.
Now, the baton has been handed to Sarah Crowley, Australia's fastest-ever female long-distance triathlete and one of six Australian women lining up in the elite women's race on Friday morning (AEDT).
The winner of seven Ironman races, Crowley completed an Australian double earlier this year at Port Macquarie and Cairns and has a whole host of other 70.3 (half Ironman) race wins, including at Santa Cruz three-and-a-half weeks ago.
The 39-year-old has twice finished on the podium in Hawai'i in 2017 and 2019 — when she set the fastest time ever by an Australian woman on the fabled course, 8 hours, 48 minutes and 13 seconds, the last time the race was run on the Big Island.
The race was cancelled in 2020, and the 2021 world championships were held in St George, Utah, with the allure of Kona ignored for another season.
That might have favoured some athletes who, with the 2020 advent of the Professional Triathletes Organisation and their big-money prize purses, have shifted the focus of some middle-to-long distance racers to other events.
But, Hawai'i remains the holy grail.
As Crowley told ABC Sport from her training base in Utah: "Hawai'i will make your career."
'Absolutely ridiculous' training days
Mostly basing herself in Park City, Utah, 2,200m above sea level for her main training blocks, Crowley trains for six hours a day.
Even she admits that sounds "absolutely ridiculous".
Every athlete's training load is different, but Crowley wrote on her Instagram feed that a typical week would consist of 21km in the pool, 450km on the bike and 90km of running.
To put those distances into perspective, 450km is roughly equivalent to riding from Byron Bay to Hervey Bay, Sydney to Wagga Wagga, or all the way around the outside of Port Phillip Bay. Twice.
In a month, that equates to roughly the distance from Sydney to Melbourne — and back again.
It's a relentless, punishing training regimen that leaves very little time for anything else.
"All you do is eat, sleep, train, recover. That's literally all you do," Crowley said.
"Every bit of time [is vital].
"If I go to a coffee shop after training, I lose recovery time. Sometimes you need it for your mental recovery but then, I could be in a hyperbaric chamber, I could be sleeping."
Crowley though finds comfort in that monotony, safe in the knowledge that she is following a process that works.
"I think, because my background in accounting, [that's] tedious repetitive work, reviewing accounts and finances, but for me, the time just goes, I get into a sort of state," Crowley said.
"It's a combination of mental and physical conditioning.
"It's so consistent that you can't mess it up.
"You get to a point where you're actually mentally so fatigued that you can't apply yourself.
"That's when you know you're close to being ready."
The Island's potent mythology is a decisive factor
The first Ironman to take place in Hawai'i was in 1978, combining the three major endurance events to take place on the island of Oahu — The Waikiki Roughwater Swim, the Around-Oahu Bike Race and the Honolulu Marathon — as part of a challenge to see who was fitter, swimmers or runners.
It was a low-key start. Twelve of the 15 men — they were all men — who started that first race finished it.
The first woman, Lyn Lemaire, competed the following year and, thanks to a Sports Illustrated article on the race, the event blossomed, moving to the Big Island of Hawai'i in 1981 and its current, famed course — a notoriety helped in no small part by its extensive television coverage and the 1989 "Iron War" between Mark Allen and Dave Scott.
The race's setting plays a pivotal role in the mystique of the event.
Oahu was the primary filming location for TV drama Lost — and there is a certain parallel between fiction and reality.
When you race on Hawai'i, the island is against you as much as your competitors are — thankfully without a crazy smoke monster or frustratingly ambiguous ending.
Crowley describes the course as "treacherous", a key factor in making this race more difficult than others.
"[It's] hot, windy, hilly, isolated, direct sun, volcanic fog, all of that," Crowley said of the hazards associated with the race.
"Then on top of that everyone is trying to race at their absolute best because it's a world championship, so people will go until they blow, so that affects the dynamic.
"Then there's media attention, the pressure and the hype.
"All of that is what makes it just so much bigger than anything else, so much more challenging."
Why the world's fittest athletes 'lose their lolly' at Kona
So what is it about Kona that makes this race so much harder than others?
Well, the distances involved are, of course, a tremendous burden on the athletes — coupled with the unique conditions.
The 3.86km swim in Kailua-Kona bay is non-wetsuit in 26 degrees Celsius water, a challenge unlike any other swim on the circuit.
Next up is the 180km bike ride across the lava fields to Hāwī and back, where crosswinds threaten to rip the handlebars from weary competitors' grasps and headwinds threaten to break their spirits.
For reference, only nine of the 21 stages at this year's Tour de France were longer than 180km — and triathletes don't benefit from riding in packs to reduce drag. They have to go it alone.
Then, the final test, a marathon along the coastline, on burning tarmac where dreams are made or cruelly dashed.
Crowley says the extensive mythologising of the race not only makes the event so special — but explains why so many athletes can struggle.
"What Kona really is, it's like the nostalgia of the whole thing," she says.
"It's the fact that you can test yourself on the same course under the hardest, most difficult conditions, against all athletes in history.
"People get deer in the headlights.
"They can be the strongest athlete and then they get [to Kona] and they're just so shocked by the whole place.
"It's so weird, whether it's the festivity of the whole thing or something else that throws people. Maybe it's the same at the Olympics, people get freaked just because it's the Olympics.
"People manage to just tag so much nostalgia in that they just lose their lolly."
For Crowley, that fear has never been a factor.
"I never actually cared for it that much, because I was a short-course athlete," she said.
Crowley used to compete on the ITU (short course) circuit before taking up a job as an accountant and shifting to competing in elite races on the weekends.
It was there that she realised long-distance races were her forte.
"I never had the ooga-booga, 'oh it's the Energy Lab', 'oh it's the whatever', I never knew anything about it," she said, referring to various stages of the marathon leg.
However, Crowley does admit Kona poses its own unique set of challenges.
"They don't know what to expect," Crowley said of the newcomers to the island this year.
"They've played it down a little bit … but they've never experienced the challenge of the island. "
Blood tests and eating disorders, how nutrition plays its role in 'the hardest sport on the planet'
As is the case with any endurance athlete, Crowley has to pay careful attention to her diet.
Leanness, after all, is a prerequisite.
"You're kidding yourself unless you're X weight, because in the women's race you have to be, say, four watts per kilo just to be competitive," Crowley explains.
"Therefore, whatever your body weight is, it has to match that."
Getting to that goal weight though, can be fraught with risk.
"I think if you over-complicate the eating, if you're too strict, you get eating disorders," Crowley said.
"What I've found more that if you become super-focused on meals, you become like 'oh I can't have chocolate today', which is shit. If you want it, have it, just don't have heaps.
"Make sure you're happy with it. That's been the easiest solution to everything. It's like little things that you learn."
However, there's little doubt that training for and competing in such a gruelling event takes its toll.
Crowley regularly has blood tests to ensure that she's not pushing her body too far into deficit.
"In '19 we got a fracture because I went to altitude for the third time within 12 months. That last little punch was enough to drop my iron through the floor. Once the iron goes, you're not transporting oxygen and the energy … comes from the bones."
While Crowley has been incredibly disciplined in the lead-up to Kona this year, she admits that wasn't always the case.
"Previously, I don't know how I got through that time without being sick or just fully broken," she said.
"The main thing now is I am so much healthier, mentally too, because you know it's real, you're not just skinny because you're doing dumb shit.
"You're skinny because you're doing it the right way and you're stronger for it, physically."
The question Crowley now wrestles with is whether the method is affecting performance.
"I feel healthy now, super strong. I'm as lean, I'm the same weight [as in previous years], but I don't know if I'm processing energy the same way," she said.
"It's something I'm constantly thinking about, has this correction and healthy way now changed how my body metabolises energy?
"Is it me getting a bit older? Or is it me not being as bad-ass and tough? That's been really challenging, I think."
With the sport itself being so unyielding, so demanding on fitness that it is paradoxically unhealthy, Crowley says it's almost inevitable some athletes will take drastic steps to get themselves in the best possible shape to tackle the course.
"It's an endurance sport, you're throwing eggs at a wall," she said.
"It's the hardest sport on the planet, it's so extreme.
"To get a win, does it actually matter [how you get there] in the long run? Other than doing illegal stuff like drug taking.
"How much is it worth to you? It's a tricky question.
"It's because it is such an extreme sport that it takes extreme measures.
"Because you're not healthy if you're racing nine hours in the direct sunlight at the speed that we're racing.
"It cannot be a physically healthy body to maintain, so how hard are you willing to take it? It's an interesting thing about Ironman triathlon."
Crowley is happy with where she is at personally though, confident that her gruelling, monotonous regime will see her secure another high finish.
She knows though, that physical preparedness is only one part of success at Kona.
"Then it comes down to am I mentally prepared and have I mentally conditioned myself for it and do I have the confidence to do what I need to do."
