Reuben Allan has not yet decided whether entering the Coast to Coast was a moment of clarity or insanity.
This weekend's event will be Allan's third time in the race which takes competitors across the South Island.
It will be the first time Allan has competed in the one-day individual event, after previously completing the two-day in 2005 and the teams' race last year.
Allan hopes to finish in 14 hours but estimates it will take between 14 and 15 hours.
The Waimate dairy farmer has been training for 12 to 15 hours per week for the past three months and 10 hours per week for three months before that.
"The event puts a lot of strain on your body. By the end of the event I'm wrecked and that's the idea," he said. "A lot of it is about being mentally strong."
The one-day event consists of cycling 140km (three stages of 55km, 15km and 70km), running 36km (including a 33km mountain stage that crosses the Southern Alps) and kayaking 67km of the grade two Waimakariri River through the Grand Canyon of New Zealand, the Waimakariri Gorge.
"It's definitely painful but you just have to focus on something positive," he said.
And it's the challenge of completing the gruelling race that keeps Allan coming back.
"It's amazing putting your hand in the sea of the west coast and then again in the east coast," he said.
"You need to have the desire to push your body to the limits but for me it's quite a personal challenge and I want to do my best."
Despite that, he admits he has a love-hate relationship with the annual event. "At the time I don't really love it but afterwards it's a feeling of satisfaction," he said.
"One difference this year is that I'm doing it in one day and I'm a little bit worried about going [for] 15 hours," he said.
"Mentally, though, I think I've got my head around the one-day event. You've got to be slightly crazy," he laughed.
The event begins on Friday at 6am.