Some crossed the finish line clutching their sides in pain and others beamed with joy, but they all had one thing in common - a huge sense of accomplishment.
About 3000 kids aged from 8 to 15 braved the rain yesterday morning and took part in the 2008 Weet-Bix Tryathlon at St Heliers in Auckland.
Kids competed individually or as part of a group in the event, which consisted of a swimming, running and cycling leg.
But winning wasn't the name of the game. It was about taking part and giving it your best. Everybody who took part received a gold medal and All Black Mils Muliaina was on hand to give some of them out.
"It was fun. I feel happy but I'm tired," said 11-year-old Olivia Timmis moments after she crossed the finish line.
The best part, she said, was the running section of the event and "the beautiful ocean".
"Swimming was the hardest. It got very deep and I got a bit scared." But she said she enjoyed it so much, she would definitely be back next year.
Parents cheered their children on and swarmed round the finish line armed with cameras to catch the moment.
A few contestants needed a bit of help getting across after over-exerting themselves.
George Scott, 13, finished the race looking wet and tired, but happy. He said the weather hadn't put him off.
"It was fun. At the beginning of the swim, I couldn't see under the water, but the water was actually quite warm ... I lost my goggles in the sea but got them back."
He reckons he came about fourth, but said taking part was the most important thing.
Twins Jessica and Samuel Jacques, 15, both completed the event. Samuel said the swim was quite hard because there were so many people in the water.
"The return trip on the bike was hard because you were pushing into the wind."
He said he trained a bit and was thinking about doing more triathlons.
More than 100,000 children have taken part in the Tryathlon over the past 16 years.
The event was first held in St Heliers with only 500 contestants.