At least six of those recently returned from representing New Zealand at the Festival of Youth in Australia were expected to be among the 180 participants.
"Anybody who wins a title will have to work hard for it, that's for sure."
Harris said the pace of the programme would also guarantee entertainment for what was expected to be a large crowd.
The first event will start at 11am and the last around 4pm and there will be four competitions running at the same time throughout the day.
"Basically, it will be non-stop action on both the track and in the field. It's a very tight schedule."
Athletes competing on Saturday will be classified into two age groups, 14-15 years and 16-17 years. They will be wearing the colours of a variety of provinces, including Auckland, North Harbour, Counties Manukau, Waikato-Bay of Plenty, Hawke's Bay-Gisborne, Manawatu-Wanganui, Taranaki and Wellington.
Of the 40-strong Wellington contingent, 13 are from Wairarapa. Contesting events in the throws will be Tim Girling-McLean, Emma Kruszona and Katie Smith, while looking to make a big impact on the track or in the jumps will be Alex Howden, Sian Chapman, Dhruv Raman, Edward Hewitt, Tyler Griffiths, Lauren Balsillie, Finn Yeats, Alison Andrews-Paul, Tessa Laven and Toyah Churton.
Even allowing for the high quality of competition, Harris says there is "every chance" of locals being among the medal winners.
"You never know who will come out of the woodwork in events like this but our lot certainly have the potential to make a decent impact and I'm sure they will."
