Sanitarium spokesman Nigel Chenery said improvements would also be made to the cycle course to reduce traffic congestion and ensure the safety of the increased number of participants.
The new cycle course will also avoid all “through” routes.
“Changes to the cycle course mean that there will be more vantage points for parents and spectators to watch the race, as well as allowing more children to participate in the event.
“The aim of the Sanitarium Weet-Bix TRYathlon has always been to allow as many children as possible to take part while at the same time giving them the opportunity to set and achieve their own goals.
“We are excited to see the huge number of Gisborne kids who are wanting to participate and are glad we are now able to accommodate them.
“We know the TRYathlon is a valuable and fun experience, not just for the kids who enter, but also for their families and supporters.”
Mr Chenery said Sanitarium worked closely with event coordinator Kathy Sheldrake and Sport Gisborne Tairawhiti to find the best venue for the TRYathlon.
The Eastland Community Trust has donated a $10 subsidy for the first 1500 children who register for the Gisborne event.
The TRYathlon is open to children aged between seven and 15.