Rotorua's Katrina Gray decided to take part in the Bissell women's series triathlon to support a friend who was training for the event.
The Rotorua woman said she enjoyed taking part in Saturday's event .
She initially signed up "to support my friend who's been training" and because she wanted to do it.
Mrs Gray was one of about 280 women who competed in the Bissell women's series triathlon at Tikitapu and was the first Rotorua participant to finish.
She was placed fifth overall.
She said she enjoyed taking part in triathlon training programmes because it was versatile.
It was not her first triathlon and she said she would encourage other women to take part in the event.
"It was fun, a fun event ... it's a really good day."
When Mrs Gray completed the event, her children Matthew, 7, and Zara, 5 congratulated her.
Event manager Brenna Roband said the official charity of the triathlon was the New Zealand Breast Cancer Foundation and many of the women who took part fundraised for the organisation.
She said the event was "fantastic" and saw a lot of first-time triathletes take part.