But interviews with the winners showed several were looking to seize an opportunity they might not otherwise get in the short term to compete at a major athletics meeting.
Maggie Jones, 8, used to do athletics but now has her Saturday morning filled with dancing lessons.
She still harbours a desire to one day be an Olympian after cheering the New Zealand team on television last year.
"I really wanted to meet Lucy van Dalen," she said.
Both Jones and Tayla Robbertsen, 9, responded with gleeful nods when asked if it was good to beat all the boys in their races. Robbertsen's current pursuits are gymnastics and netball, but she was looking forward to racing under the lights next week.
They say you shouldn't argue with a confident man, and Fraser Belliss, 7, fit that description.
Enjoying both sprinting and jogging in his own time, he was asked if he could win his race at the classic.
A moment's pause to scrutinise the situation with a thoughtful expression gave Belliss time to formulate a fair appraisal "yep".
Alex Palazzo, 5, is a member of the athletics club and comes from a family mad for those sports his brother recently getting into a spot of hot water for putting a shotput through a window at their house.
Dillon Adrole, 11, was another who used to do athletics and seized the chance of an open public trial to earn a spot at the starter's gun next Tuesday.
"It's going to be fun," he said after completing the 100m race the younger grades dashed 60m.
All children had their contact details taken as McNab told them they might still be approached to have a go in the children's races on the night to complete the fields.
But for those who missed out yesterday or just found out about it for friends, there are still three more Fastest Kids competitions around Wanganui this week.
Today the races will be held at Castlecliff Domain, tomorrow at Peat Park and Thursday at Williams Domain.
They all start on the starter's wooden clacker at noon.
