After having a year off to start a family, three-time Hawaiian Ironman world champion Mirinda Carfrae will return and take on Swiss star Daniela Ryf.
Mirinda Carfrae knows better than most that even Daniela Ryf is beatable in Kona.
While Ryf is one of the strongest women's favourites in the 40-year history of the Hawaiian Ironman triathlon world championships, Carfrae is far from daunted.
The Australian triathlon great and Ryf are three-time winners.
On October 14, Carfrae will return to Kona after a taking a year out following the birth of her daughter Isabelle, while Ryf has won the last three editions of triathlon's most famous race.
Two years ago, the Swiss ace broke Carfrae's course record as the Australian finished runner-up.
In July, Ryf reaffirmed she is the woman to beat in Hawaii when she won Ironman Frankfurt by a whopping 26 minutes and finished seventh overall.
Yet strange things happen at the Hawaiian Ironman, which is notorious for its humidity, strong winds on the bike leg and massive amounts of pressure on the main favourites.
"If she races like that (Frankfurt), then I don't think anyone will touch her," Carfrae told AAP.
"But this is Kona ... it's a strange event - crazy things happen before the race and during the race.
"Don't get me wrong. I will need a perfect day to contend with her, but it's possible and that's all I need."
Carfrae, 37, has bitter personal experience of what can go wrong in Kona.
After first winning Hawaii in 2010, Carfrae was outstanding with successive titles in 2013-14.
But two bike accidents in the lead-up to the 2015 race diminished her chances and she eventually pulled out during the bike leg with a back injury and watched Ryf win for the first time.
Immediately after the 2016 race Carfrae and her American husband Tim O'Donnell, also a top-three finisher at Hawaii, decided to start their family.
Carfrae says life as an elite triathlon couple with a baby is a "circus", but she loves it.
"We changed our whole lives in the most positive way, the most fulfilling way possible," she said.
One of triathlon's most ferocious competitors added that going through pregnancy and childbirth had altered her perception of pain.
"It resets your boundaries on how hard what you're doing is," she said.
"I find that training, in comparison, is kind of laughable."