The mates from Orange will board a plane to Papua New Guinea to try to walk the Kokoda Track in six days.

The 110-kilometre journey to Port Moresby typically takes between seven to nine days, so the group's training schedule has been gruelling.

Fitness Perfection owner Nick Gray led the gym members through a 12-week program which began at the start of January.

He said the sessions, provided by their trek leader from Taurus Trainer, involved strength work to get their legs ready for the tough, uphill climbs.

The group met up to four times a week to walk, with hikes of up to 20 kilometres along trails through the Mount Canobolas State Conservation Area on Saturdays.

Working at different businesses, including PJL Group, Jack Evans Workwear and Camping, and Craig Jaques and Associates, Mr Gray said it wasn't always easy for the whole team to find time off together, but the week before departure no one is lagging too far behind.

"We've all had little falls, a few bumps and bruises ... more a matter of wear and tear but we're 95 per cent fit and ready to go," he said.

Getting there required a little more sacrifice for some: Phil Wilkin, Craig Jaques and Brendan Rouse went on a "body reset" diet for 10 days, restricting their food intake to 800 calories a day.

Maintaining cardio and strength-based workouts on a meal plan of poached eggs, salads, tuna and chicken resulted in weight loss of about eight kilograms each.

Mr Gray said their 10-day diet will be pretty similar to the tinned beef and chicken dinners they'll be eating under the stars all next week.

While the physical challenge must certainly have contributed to the high-energy gym owner pitching the idea for the trek, he said it's more about connecting with "the spirit of the Anzacs".

"We've all got some sort of passion or want to learn more about what happened," he said.

"To do something like this and to do it with a group of mates - it's awesome."