And he's not the only one. Andrew Hedgman, a 25-year-old New Zealand-born ultrarunner, is currently running from Brisbane to Sydney: 1000km in 14 days. Three years ago he ran the length of New Zealand. Meanwhile, the Vibram Tarawera Ultramarathon, probably New Zealand's premier off-road ultrarunning event, now attracts nearly 300 happy customers each year: men and women who pay good money to line up in the dark and run up to 100km without a break.
The question is: why?
Running long distances goes way back. In his ultrarunning best-seller, Born To Run, Christopher McDougall theorised that humanity's ability to run long distances and refuel on the hoof developed into a vital "persistence hunting" strategy for running prehistoric prey animals to exhaustion.
The word marathon itself comes from the fabled Pheidippides, who died after running the message of victory to Athens from the battle of Marathon in 490BC. The Tendai School of "Marathon Monks" in Japan have reportedly been doing their daily rounds of up to 84km since 1585 and a Norwegian sailor named Mensen Ernst made a name for himself by claiming to have run from Paris to Moscow in just 14 days in 1832, averaging 200km a day.
This demonstrates two things: firstly, there are always a few mad people out there willing to try anything; secondly, the easiest answer to why some folks run a long way is simply because they can. But that doesn't explain what motivates people to push through the enormous pain involved, or, given that pain, the sport's growing popularity.
Alongside enduring the pounding ache of seemingly endless kilometres, Mal Law also managed to severely sprain his ankle last year on a solo training run in the Waitakeres and had to hobble his way out.
"There's a degree of mental toughness and bloody mindedness," he says. "I've always got niggles and there's no such thing as a pain-free run these days. I just think ultrarunners are good at using the top two inches of our bodies to battle through. I guess the main strategy I use is to break it down into small goals. You don't think about how far it is to the end, you think about the next aid station, next time you see the support crew, just getting to the next place to get water out of the stream. That way you have lots of little goals rather than one incomprehensibly big goal, that seems to make things easier to get through."
Some of these events are, of course, for charity. Law raised nearly a quarter of a million dollars for the Leukaemia and Blood Foundation doing the 7-in-7 in remembrance of his brother Alan, who died as a teenager from the disease. His latest odyssey is raising cash, some might say ironically, for the Mental Health Foundation. But speaking to him, it becomes clear why he chose this type of challenge and why he would probably be doing something similar with or without a cause to run for.
"I think it comes down to the fact that I get a huge amount of reward from it," he says. "I get reward from the physical gratification: taking on a big physical challenge and succeeding. It's also just a love of adventure that goes back to boyhood. My dad dragged me up mountains in Scotland and my reading was Swallows And Amazons. To me it's not so much about being competitive, it's about the adventure. And I love the camaraderie that comes from running these long distances, it creates some very special friends and special bonds."
Athlete and coach James Kuegler, on the other hand, is more of a competitive animal. He represented New Zealand in last year's Commonwealth Mountain and Ultra-Distance Championships, coming home in 14th place after running 54km in just under four hours. His marathon personal best is 2:37:53. But he shares a passion for ultrarunning with Law that borders on the spiritual.
"It's about getting out into the wilderness in New Zealand and fabulous places around the world that I would never see otherwise," he says. "And putting my body into that present-time consciousness state of just being at one and going through the process of running. There's a lot to be learned about the body and the mind from running for such a long period of time."
For New Zealand's international ultrarunning teams to do well on the sport's increasingly large world stage, they will need increasing support from the Athletics New Zealand's national organisation. But like any sport ultrarunning will also need a good number of grassroots events and plenty of participants to select from. Which is where events like The Vibram Tarawera Ultramarathon come in.
Created in 2009 by race director Paul Charteris, and organised in his spare time, the 100km event takes place on the established trail network between Rotorua and the timber town of Kawerau, where Charteris grew up.
From fairly humble beginnings, it now attracts a hoard of ultrarunners from New Zealand and overseas, and last year gained sponsorship from Vibram, the US footwear giant that makes the specialist "barefoot" FiveFingers running shoes beloved by many in the sport. It also attracted a guest star appearance from US super-runner Anton Krupicka, who has been setting course records and winning races all over the well-established US ultrarunning circuit since 2006.
The event's formidable growth is another testament to the sport's increasing popularity, which Charteris puts down to its "incredible simplicity".
"All you need to do is put your shoes on and head out of the door," he says. "Sixty kilometres is achievable by anyone who can run a road half-marathon. But you have got to work for it, which means you are excited and scared at the same time. There is a real palpable sense of achievement."
Obviously the right to skite over lesser mortals who have "only" done a marathon must come into it but it doesn't come easy. This year Law has averaged just over 100km of running a week, generally on tough, hilly trails around the Waitakeres, putting in anything from 15 to 20 hours a week. Even the least experienced ultrarunner I spoke to considers dragging himself out of bed at 4.30am every other Saturday to be the acceptable price he pays to pursue his chosen hobby.
Jason Rudkin-Binks is a partner in an Auckland law firm. Originally from Britain, his running addiction took hold when completing the iconic London Marathon turned out not to be enough.
"I always had the urge to do something a little bit more," he says.
"You meet a lot of people who have done a marathon. It was testing myself. Believing mentally I could do it. We so under-use our bodies at the moment that if you train hard there's very little that can't be achieved, it's just that most of us don't do that most of the time."
Upgrading from London parks to New Zealand's wide open trails inspired him to keep stretching himself, to the point where he has now completed the 85km version of the Tarawera course and has signed up for the full 100km next year.
"I am not superhuman and I don't train a massive amount. I think these events are very accessible to anybody if they are willing to put a reasonable amount of effort in and have the belief that they can do it if they try," he says.
"When I completed my first ultrarun I was so elated that I had managed to achieve this goal, it was an unbelievable buzz. It made me hunger to do more and go further. When you take that single step further it's really exciting to see how far you can go."
But perhaps most telling of all is not what happens at the big events but what happens to these people when they are on their own on those murky mornings out in the woods. Because if all these ultrarunners have one thing in common, it is that, ultimately, they run just for the love of running, as an end in itself.
"I remember going through a very dark spot on my first Tarawera," says Rudkin-Binks. "It was awful, I felt depressed, having spent all year pushing myself to do this one thing. The only thing that pushed me on was how gutted I would feel if I gave up. But running for me is like having my own personal shrink. In my busy life to disappear for four or five hours with just me and my music and to let go of all the demands on me is just absolutely wonderful. It's a mental holiday one day a week. You feel like a million dollars for the rest of the day."
The next ultrarunning event is the Great Naseby Water Race, near Naseby - the highest town (at 610m) in New Zealand, near Ranfurly - in August.
Armchair ultrarunning
Ultrarunning (aka ultramarathon running) is defined as running any distance significantly longer than the 42.195km acknowledged as the "standard" marathon distance.
The latest wave of interest in ultramarathon running has been fuelled by two books that have become best-sellers worldwide.
* Ultramarathon Man: Confessions Of An All-Night Runner, by Dean Karnazes (Penguin, $19)
The thoroughbred show pony of the ultramarathon world, 49-year-old Karnazes has run 350 continuous miles through three sleepless nights, won the Badwater Ultramarathon by running 135 miles non-stop across Death Valley in summer, a marathon in Antarctica and a 322km relay race solo 10 times. His compelling book covers what he does, how he does it, and why.
* Born to Run: The Hidden Tribe, The Ultra-Runners And The Greatest Race The World Has Never Seen, by Christopher McDougall (Profile Books, $27).
An intoxicating combination of ripping adventure travel yarn and extreme sport biography, McDougall mixes the latest research and jaw-dropping insights into some of history's most amazing runners as he tries to track down a cure for his own recurring running injuries. Meanwhile, he gets caught up in a 80km wilderness race in one of the most dangerous places in the world, between some of the world's top ultrarunners and a tribe of Mexican super athletes.
