"I joined about a year ago to do this 100, and the 50 was in that programme."
A long-time marathon runner, Crowley began to look for new challenges.
"The last couple of years I've done some off-road marathons and that has progressed to the 50, because it was there, and the same with the 100. There's a lot of Rotorua Trail Running Club people do the longer distance, so you get dragged into these things. And there's always that thing of seeing these people do it and thinking 'I wonder if I could do that?' I guess I'm going to find out."
At 62km, Crowley will be joined by the first of two pacers, Chris Corney and Bruce Edwards from Lake City Athletic Club, who will help her through the final 40km.
"I think if the physical side holds together than I should be fine; the mental side of it, they will take care of because they will make me do it.
"A big part of it is making sure I get to that point in good enough condition, because you can wreck it, of course, if you go too fast at the beginning for your ability, then you're not going to survive it to the end."
Both Corney and Edwards are good marathon runners.
"They are very experienced and very competitive so they will be good people to have pacing for me, just to keep going. My job is to be in good enough condition so they get a bit of a run, otherwise they will find it very frustrating."
A big part of successfully tackling a race of the magnitude of the Ultra is experience, the paradox being you need to take part to get the experience.
"Of course, I haven't done one before, but working with Squadrun, I've got the average pace I should be going, so I will be trying to be sensible about it."
Crowley is aware that when the adrenaline starts to flow, the urge to go out too fast will have to be kept in check.
"It will be interesting to see the mood people will be in. A lot, myself included, will be thinking 'oh dear'. But everyone will be feeling good because they have been tapering off for it."
Crowley is expecting a lot of support on the course and from those taking on the 62km run who will start at Millar Rd, Lake Okareka, an hour and a quarter after the main field.
"The 62km people, they will get to see all the fast guys, which will be cool for them, and everybody finishing at Firmin Field will be cool. It will be a pretty good atmosphere."
Other top level Rotorua competitors in tomorrow's race include Darren Ashmore, Rich Barter, Piripi Inia, Mere Murray and Chris Townley.
The 102km and 87km race runners will start at the Redwood Visitor Centre at 6am with the 62km runners starting at 7.15am.