The 43-year-old won the world 24-hour solo mountain title in her age group.
The Moana Pool programme co-ordinator braved freezing and wet conditions in the Highlands of Scotland and was not that far behind the leading elite riders.
She completed 19 laps of what she described as a technical course - seven more than her nearest rival in the category.
Last year she had to put up with baking temperatures in Italy and terrible chafing.
But her body held up a lot better this time and the jet lag actually helped her pedal through the dark hours in the early morning.
That said, the event was tougher than she thought it was going to be.
"[The track] was a lot more technical and it rained for about 20 hours," she said.
"It was pretty cold."
Mentally it was draining but all those long training session in the middle of the Dunedin winter paid dividends.
"I'd trained for it, so it wasn't too bad. But you get sick of it. It does wear you down a bit."
The loop track was about 12km and about 400m of that was made up of some testing climbs.
The downhill section was a relief and despite the rain the track held up well,
Cook had to stop each lap to clean the mud out of her chain, though. The elite riders had two bikes and lost less time.
The next event is in Brazil next year and Cook is still weighing up whether she will defend her title.
She did not have a lot of competition in her age grade and is considering entering the elite grade. But it will be expensive and she would need sponsorship.
