About 1000 women of varied age and ability gathered in perfect weather for the 3.5km run or walk, 10km bike ride and 1.5km run or walk.
Cate Davis, of Wanaka, said she completed the course in 1hr 35min by her watch.
It was the first time she had entered the duathlon, after spectating last year.
Although she had undergone three heart operations before she was 5 years old, the 41-year-old said her biggest fear was falling off her bike.
"It was tough going in places [but] I had a really strong determined streak to finish ... I met people from all over and we kept each other going.
"It's a wonderful atmosphere and I'll definitely come back next year," Ms Davis said.
Arrowtown resident Teresa Bagley, who lives with Alzheimer's disease, suggested to pals Alison Mitchell, Erin Kirk and Pip Craigie they enter.
The pals rallied round and joined in, "to prove you can do all sorts of things with the support of friends," Mrs Craigie said.
Husbands, brothers, sons and supporters cheered from the sidelines.
Among them was Dunedin man Mark Hastie, who proudly urged on wife Jo and her three friends, who had entered for their third year.
Mr Hastie said his wife had trained with their 11-year-old daughter on bicycles.
She would probably join her mother in the run or walking stage next year.
At the end of day prizegiving race director Jane Patterson told the crowd the aim of the duathlon was to provide a safe, supportive and non-competitive event for the sorority of women.
She hoped they would stay active in the event and other races.
A St John Wakatipu paramedic said there had been minor treatment for pre-existing injuries, but nothing acute.
