There were 250 volunteers from community groups helping out at the event at the transition areas and lining the course to help any children that needed it.
At the finish line, Mayor Greg Brownless and Bay of Plenty MP Todd Muller helped Olympian medallists Luuka Jones and Sarah Goss hand out medals to all the children.
Nine-year-old Adam Bax threw his arms in the air in triumph as he celebrated crossing the finish line at the Tryathlon andsaid it was amazing to finish such a challenging event.
"It felt amazing when I finished. I felt relieved as well. It was really exciting."
It was Adam's first time completing the Tryathlon as he had recently moved to the Bay from Whangarei.
"Where I used to live, they didn't have the Weet-Bix Tryathlon so this is my first one - but I will definitely do it again."
He was proud to receive his participation medal from rugby sevens player Sarah Goss.
Adam's favourite part of the event was the swim - even though he was scared when he saw other children struggling in the water.
"It was so scary at the start, but I pushed it all out and went forward."