About 700 athletes of all abilities are expected for the Smith Sport Shoes Tauranga Trail Run, an event the local schools and community really get in behind.
The run is in its second year after more than 500 runners and walkers participated in the inaugural event at the Tect All Terrain Park in 2011.
Organiser Scott Furness said the event was popular because it was family-centred, eco-friendly and a real off-road adventure.
"We have a distance for every age and ability, from 5-years-old to 95," said the 41-year-old teacher at Tauranga Boys' College.
School staff, students and parents came up with the idea for this run in 2010, and do all the organising, source all the spot prizes and act as course marshals on the day.
The event is a fundraiser for the Tauranga Boys' College cross-country team, who are one of New Zealand's best school teams.
They also plant a native tree for every participant and "pay it forward" by working on trail construction and maintenance at the park.
"We get great support from the locals as it's a fundraiser for the Boys' College. We offer other schools the chance to use it to fundraise as well by having food stalls on the day. It is great seeing everyone come together."
Furness is well qualified to take charge of the event. He has organised numerous triathlons and duathlons for children in Gisborne and Tauranga over the past decade, and is a competitive age-grouper in local triathlon events.
He recorded a best time of 9:48 for the New Zealand Ironman and has achieved a number of age-group placings in NZ Half Ironman champs in the past three years.
He says the Tauranga Trail Run is all about being inclusive. There are walk and run options over 5km, 10km and 15km, but the 30km race is for runners only.
"The key to running this course well is start off nice and steady so that you have energy to finish strongly, as each distance is peppered with rolling climbs and the last piece from the Te Rerenga Tunnel to the finish is almost all uphill for 1.5km."
George ter Wal is a fellow teacher at Tauranga Boys' College and is up for the challenge of running the 15km.
The 62-year-old, who has run one marathon and a few half-marathons, has been running 8km three or four times a week in preparation.
"I run at old man's pace, to relax rather than to turn into a real runner," said Ter Wal.
"This one is special. It is a cut above a half-marathon. It may be only 15km but it feels like more."
Ter Wal competed in the event last year and runs the trails in training with his mates. "There is a great variety of terrain which makes it a challenge - some mud, some gravel, some pine needles and lots of single track through native bush.
"The bit after the tunnel is, in my opinion, one of the prettiest combinations of bush and boardwalk I have seen anywhere. Running in a tunnel is pretty cool as well.
"Also, on a good day you can see Mt Tarawera from the highest point on the course."
Gareth Osmond is another entrant and family man who is coming back for more - this time with his wife, Melissa, and 7-year-old son Zavier.
"It is very important to do events like this as a family," said the 33-year-old who has a varied sporting background in cricket, football, mountain biking and most recently CrossFit.
"My son will be running in the 5km children's event accompanied by my wife. He is already talking up his chances," said Osmond.
"It is great to have events that we can all participate in, it gives us more in common and my son especially enjoys telling others of his performance."
Osmond will be taking on the 15km and is expecting a tough afternoon.
"It is rugged, varied, but beautiful. Very interesting features such as the hand-dug tunnel ... I have done minimal training and can probably cover the 15km."
"There were a lot of people involved in this event last year, and I would expect to see numbers increase. It would be great to see this event continue to grow."