''It's part of my life. You are constantly at it. But it's good. I wouldn't have it any other way. Love it.''
But the ever-positive Murray-Orr has plenty of stuff to be worried about in the biggest Challenge yet.
The weather forecast is just average. The running course alongside the Clutha River is flooded.
She needs a couple more volunteers on motorbikes. A few more officials along the running course would help.
And another kayaker or two would make the difference.
But, there have always been problems of this sort and worse - sponsors dropping out, retailers unhappy about street closures, and a lack of support at times from some local politicians.
But the Challenge has not only gone on, it has mushroomed into an event of national significance.
In 2008, the event's second year and Murray-Orr's first year in charge, there were 112 individuals entered and 61 teams.
This year, more than 2000 athletes will take part in events through the week of what is billed as New Zealand's largest triathlon festival.
The flagship event, Challenge Wanaka itself, has 1500 athletes from 20 countries racing either half or full Ironman distance.
Prize money totals $80,000.
Murray-Orr describes this as a record year for the event, despite a clash of dates created by rival franchise Ironman holding a new half-ironman in Auckland the day after the Wanaka event, forcing athletes to choose one or other event.
''They created a clash. It was disappointing for the sport because it forces athletes, sponsors, suppliers to choose, when really, there's another 51 weekends in the year when it could happen.
''It's frustrating but at the end of the day, they do their thing, we do ours.
''We know we have a spectacular course down here. I think the athletes vote with their feet.''
Murray-Orr grew up in Devon and Cornwall, worked in public relations in Bond St, London, and came to New Zealand 13 years ago for a three-month sabbatical.
She has been here ever since, working in the ski industry until the opportunity to organise the Challenge came her way six years ago.
''Right place, right time. It's one of those once-in-a-lifetime opportunities that comes along and you grab it with both hands.''
One of her biggest challenges each year is ''creating infrastructure''.
The most obvious is the marquee on Pembroke Park, shipped in from Christchurch.
''There's no infrastructure here in Wanaka that's big enough to hold the event. So we have to build our own.
''Putting on an event here in a small town at the bottom of New Zealand is challenging.
''We're a long way from any infrastructure.''
Murray-Orr says it is only because of the efforts of 700 volunteers that the event continues in Wanaka.
''Without them, Challenge Wanaka would not exist.''
She says race day will be a 24-hour affair for the ''core team'' of race organisers but then, on Sunday night, it will be time to relax and celebrate.
''And then we are back into it Monday, clearing up the park, and then we have debriefs and our reports ...''
And, she says, that is also when planning will start for Challenge Wanaka 2014.
