Bay of Plenty's Sandy Boubee and Debbie Clark are about to take on the toughest challenge in endurance racing on the planet.
The two Tauranga residents are set to compete in the notoriously tough Ironman World Championship in Kona, Hawaii, early next month.
Boubee, 44, has more experience at competing over the gruelling Ironman distance than Clark but she knows there is no comparison with the conditions in Hawaii.
To add to the emotional drama she will miss her son Luke's sixth birthday the day she leaves.
"The biggest issue is the uncertainty we face after training in the wind and the rain we have had here, then going into the 38 degree temperatures and humidity," Boubee said. "I know I am not one who copes well in the heat, so I am not going there to race but to participate and finish."
Boubee competed in her first Ironman NZ event at Taupo in 2000 and quickly showed she was suited to the tough racing format, finishing second in her class in 2002 and qualifying for Hawaii.
Her new coach John Ackland, and an Arthur Lydiard-like training regime dominated by hill work, made all the difference.
But because of work and financial factors she could not go and once daughter Alex was born, she put racing on hold for 10 years, until she decided to return to training early this year.
Clark did not take on the triathlon and ironman challenges until she retired from teaching at Otumoetai College in 2009, but she had a successful background in elite sport to call upon. In the 1970s she represented New Zealand in gymnastics, before excelling at tennis and snowboarding.
Now 55, she regards the Kona Ironman as the toughest test of all.
"Most triathletes want to take it on and for me it is a test of pushing yourself to your limits," Clark said. "Mental strength is the key and I have always been a driven person."
Clark remembers being in awe of Boubee competing in triathlons but a complete dislike of swimming meant she could never imagine taking on the challenge.
"I was never a swimmer and at the start it was a real issue. But I went to swim coach Sheryl McLay and she was amazing. I now love swimming."
The catalyst for Clark to target Hawaii came last year at the World Long Distance Triathlon Championships in Las Vegas, where she was stunned to finish third. This year, she won her age group in the inaugural Melbourne Ironman, which qualified her for Hawaii, but not before she had a major problem with her bike.
The inspirational figure of All Blacks captain Richie McCaw came to the rescue.
"I stopped, looked at my bike and thought to myself 'this is my race over'. But then I thought of Richie in last year's final against France and asked myself what would he have done?
"He would have changed the game plan so I got the bike, found an official and fixed the problem to win by an hour and a half," said Clark.
Some more McCaw inspiration may be needed, as the pair put themselves through the toughest ordeal of their lives.