"It was a really good way to get in the headspace of where the athletes are going to be, so it's a really good reminder of what we need to provide to them along the way.
"I came up with the idea that I would do it as an overnight run myself, so at seven o'clock on Sunday night I donned the gear and disappeared from the Redwoods and turned up in Kawerau at seven o'clock the next morning."
A little earlier, to be exact. Day clocked the course at 11h 47m. Along the way, he counted the animals he passed.
"You've got to have these little motivational things," he says. "It just transpired that as I was out there I started counting wildlife. I just started, and it spurred me along - you know, 'when am I going to see the next wallaby, when am I going to see the next possum?'. For some reason it worked."
Day navigated the forestry roads and paths by way of a headlamp. Aside from that, it was pitch black, but Day says the limited visibility actually assisted him.
"What it does is just focus your thoughts on what's in front of you. Literally you [only] have a pool of light, so you're not thinking, 'I've only done 20km and there's 80 to go'. You're just thinking about the next piece of trail in front of you.
"From a psychological perspective, that's probably how every runner should approach it, because it's a bit daunting if you think about the whole thing all at once."
Day's escapade has given him some empathy for what contestants will be up against next weekend.
"Ultra running is all about drawing from within yourself," he says. "If you've done the training, physically you're capable of getting there, but it's very much a mental game."
But beyond that, Day was reminded of something about the course that was a little more straightforward - "it's a bloody long way".
Tarawera Ultra-marathon
When: Saturday, February 7.
Options: 100km, 85km or 60km.
Start time: 6am at the Redwoods Visitor Centre in Rotorua.
Event sold out for 2015.
For more information: www.taraweraultra.co.nz
