There were also no accidents, other than a few twisted ankles, due to people being a bit more careful going through so much mud, he said.
Numbers were up from about 450 last year and on par with the first year in Hawke's Bay when they had 600, he said.
For the last couple of years, Clifton Station's owner had made mud pits to ensure plenty of mud on the day which had helped boost numbers, Mr Fleming said.
People came from as far south as Wellington and as far north as Hamilton.
Today there will be 1250 primary school children using the course which is a great way of safely getting students out of their comfort zone, Mr Fleming said.
The event is held in six locations around the country every year and has been in Hawke's Bay for the last four years.
The national event started 15 years ago with one location and 400 competitions and now has about 25,000 participants around the country.
The courses include swamp crossings, a spider's web net climb, crawling under barb wire, native bush trails, tunnels, hurdles, a climbing frame and plenty of mud.