Record numbers competed in the Canberra Weet-Bix Try-athlon on Sunday with more than 1650 kids racing at the AIS.

The event is for children aged seven to 15. The seven to 10 age group do a 75-metre swim, 3-kilometre cycle and 500-metre run, while 11 to 15 do a 150m swim, 6km cycle and a 1km run.

Canberra Raiders captain Jarrod Croker and Olympic runner Mel Breen greeted the competitors at the finish line.

"The kids showed a lot of pluck today and we had an absolutely perfect day for it," organiser David Martin said.

"The kids were stoked to see Jarrod and Mel at the finish line. The kids are pretty aware in Canberra of who they are and Jarrod came last year as well, he's a real supporter of the program.

"We found working with AIS was great and are looking forward to coming back next year with hopefully even more kids. We want to continue to bring these sorts of experience to kids to build their confidence in outdoor physical activities."