"Once you explain the rules in detail they are all pretty good," she said.
For ages 7 and 8 athletes are divided into divisions, with each division having winners and an Olympic-style award ceremony. Other age groups have qualifying heats before winners are decided.
The naming sponsor's red marquees feature alongside the running track's home straight, proclaiming teeth should be brushed twice a day and flossed once. Athletes are given packs including toothbrushes, dental floss and toothpaste.
Colgate general manager John Garside said the company had sponsored the Games since 1978, so some participants were third-generation competitors.
He said the outstanding performance of New Zealanders at the Rio Olympics had renewed young people's interest in athletics.
New Zealand Children's Athletics Association president Brian Cockeram said the event was about bringing the athletics community together in the spirit of true sportsmanship.
"While the focus is on participation, Colgate has provided four scholarships named after Colgate Games alumnus and Olympian Nick Willis, worth $500 each to athletes who display outstanding performance."