Of all the competitors' stories at the Speight's Coast to Coast, perhaps Steve Maitland's is the most inspirational.
Maitland, who turned 60 earlier this year, faces the same daunting challenge of 243km of cycling, boulder-hopping runs and rapid rivers but does it on one leg.
Maitland's pre-race preparation yesterday morning carried an added twist. Backpack? Check. Cap and sunglasses? Check. Food and water? Check. Different artificial limbs for run, cycle and kayak legs? Check.
"This will be the 10th time", says wife Kath. "It was a birthday present to himself and he wanted to make up for last time."
That was 2006, when Maitland failed to complete the one-day event under the cut-off time. On seven previous occasions before that, he had successfully completed the course in either the one or two-day event. He won the family team category (with brother Robin) in 1996 in 12 hours and 19 minutes and once set an age group record for the 67km kayak sector.
"You get a bit soft in your old age," says Maitland, "relaxing with TV and sitting around. This is a bit of a tune-up for me and it's good to hurt a bit."
There was plenty of pain in Friday's mountain run, where he spent about eight hours negotiating the 33km across numerous riverbeds and over a mountain pass. Anyone who has hopped rocks at a beach knows how hard it can be but here, there are boulders the size of small cars, as well as waist-deep river crossings.
So exactly how do you do it with an artificial limb that, despite all the advances in technology, can never provide the strength and flexibility of a functional ankle joint?
"I've always had good co-ordination," says Maitland. "And I think I am boulder-hopping better than ever. It's a bit like driving; you are always looking ahead and your mind already knows the next step."
He fell head over heels in a practice run but was unscathed on Friday, tripping at one stage and getting the limb "jammed" between rocks on a couple of occasions.
Last year, Maitland had been troubled by a nerve pain near his stump - which he says felt like someone putting a skewer into his leg - and had to stop every kilometre to rest and take off the prosthetic. Surgery alleviated the problem and he feels "more comfortable than he has ever been".
"I think most people admire him," says Kath of the other competitors, "though a lot of people don't like being beaten by him. He beat a few yesterday."
For the brief run off Kumara beach on Friday (3km), Maitland used one of his older limbs, before slipping on his cycling prosthetic, which he has specially modified. It doesn't have a foot; an aluminium tube clips directly into the cleat. The run required a newer limb before the specially adapted leg for the kayak. Instead of foot pedals, he changes direction using a tiller bar which he bangs from side to side with his feet.
The technology has developed markedly since Maitland's first Coast to Coast in the 1980s.
"I was using the same things you saw in the Boer war," says Maitland. "Basically fibreglass and a wooden block at the bottom."
His running legs used to last about three months (750km) before they would break but now they are more durable.
In his time, Maitland has also been a tester for the Christchurch Limb Centre, able now to laugh about one occasion when a limb snapped after about a week, when he was on a training run but thankfully only 5km from home.
After a motorcycle crash at the age of 19, Maitland developed an infection in the wound which later forced an amputation just below the knee. After spending three months in traction, Maitland drove to Auckland - on his motorbike, within a week of being discharged. Life wasn't easy for an amputee in the 1970s but Maitland was determined to defy stereotypes.
"You were put down the bottom of the heap - like you weren't worth anything - but I knew I was an athlete," says Maitland. "I wanted to show that disabled people are worth more than the way they were being treated."
A keen sportsman before the accident, Maitland turned to kayaking before taking up multisports in his late 30s.
Tomorrow, Steve and Kath will return to Ross (population 300, near Hokitika) where Steve works as a jade carver. Maitland doesn't see himself as special but hopes he has made a difference in his own way.
"I hope I have set a bar for what is possible for amputees," says Maitland. "But I'm not special. I've been inspired by meeting people like paraplegics who are much worse off than me and they just get on with it. It's about grabbing life with two hands and making the best of what you have got."