He says that it is no coincidence that this event is notoriously tough.
"The tagline is, in the first instance, a salute to all those high-country stockman out there, and to the very long and often very hard days that they put in day in and day out," said the 44-year-old who is a keen mountain-biker.
"If they're not tough enough you don't tend to last too long in the high country."
The series is in its second year after a successful inaugural staging last year, where 45 athletes competed. About 120 are expected next weekend.
According to Lunn, three factors make the James Mountainsport Series unlike any other in New Zealand - the history of St James, the landscape and the environment, and the challenge.
"All competitors will cross at least one mountain pass in excess of 1300m, and all courses have an average altitude change of between 800m and 900m.
"As much as possible, the course routes follow old stock tracks and heritage-listed stock routes and 4x4 tracks - there is probably less than 2km of metal road in the whole event," he said proudly.
Lunn is also proud to continue his family's connection with the land and produce an event that is befitting to the heritage of the stockman country.
The result is a challenge like no other in New Zealand, and one that will make you a man or break you.
"There is no 'easy out' once you start," said Lunn. "There is no support crew. You're on your own and I am more likely to provide you with incentive from the stock whip than hold your hand.
"But in all seriousness, a big part of the concept for me is the challenge of completing your race on your own," he said.
James Series
When: Saturday, January 26
Where: St James Station Conservation Area, Hanmer Springs
More information: stjamesmountainsports.co.nz