The 42-year-old, who has twice competed in the 217km Badwater Ultramarathon race in California's Death Valley, is now aiming to crack the 300km mark with a run from Mt Cook to Oamaru.
All going well, he will become the first person to run the 301km Alps 2 Ocean Cycle Trail non-stop when he attempts the feat from April 29.
The run would take about 40-48 hours, he said.
"I guess the incentive is just to see how far you can run and for how long.
"I keep saying it's just a phase I'm going through but the phase has been going on for about 10-12 years.''
The track had been run once before, an effort which took eight days, Sutton said.
He would have a support person beside him and a vehicle in front of him throughout the run.
The vehicle would be carrying things such as clothing, food and water.
He had recently gone away from food gels and sweet foods such as chocolate to "real food'' such as fruit cakes and muesli bars, and had ditched Powerade for water and electrolyte drinks, he said.
He had completed three 100-mile (161km) races in the past year, in Naseby, New Plymouth and the Northburn race, near Cromwell.
The Cromwell race was just three weeks ago.
Those races had formed the basis of his training for the Mt Cook run, he said.
"I've obviously got quite a lot in the bank, doing those 100-milers. I get out every second day and run anywhere from one hour to eight hours.
"I'm just trying to be consistent with that.''
Sutton and a friend had been holidaying in Mt Cook for years and he had been thinking about running the track for quite a while, he said.
"For me, it's piece of mind.
"Who knows? I might make a race out of it next year if it goes all right.
"There's nothing more than 100 miles in New Zealand. It would be perfect for a race.''
A core group of three people would be with Sutton throughout the run and others would join for various stages, he said.
He would begin the run at 8am.
