Sport Whanganui marketing and communications officer Keeley Eastwood said 26 schools throughout the Rangitikei district would be involved.
"A professional timing team will be timing kids," Eastwood said. "The Downs Group Rangitikei Tough Kid began in 2012 and was born of the success of the Wanganui Tough Kid.
"It has grown year-on-year, initially attracting about 270 kids, and we are expecting more than 1000 on Friday," he said.
As well as the youngsters, there will also be a parents and teachers race. Across all the age groups, last year it was South Makirikiri School that proved the toughest, followed by Hunterville and St Joseph's Taihape.