They raised thousands for men's mental health but tyre-flippers Gareth Edwards and Tom Moore went to some dark places to do it.
The Aucklanders took 10-minute turns to flip a 93kg tyre for 24.7 km at the Millennium Institute in Albany over the weekend, raising more than $11,000 for the Sir John Kirwan Foundation.
Moore hit a physical hole on Sunday morning while Edwards had an emotional collapse later on as they set the Gunness World Record-approved mark in front of 50 friends and supporters.
"With about an hour to go I was told we had raised $10,000 and I couldn't hold it in anymore and broke down," said Edwards.
"It made me realise how much had been involved in just organizing the whole thing. There had been 20 weeks of tough preparation - we put immense pressure on ourselves and I hadn't really realised the extent of that."
Edwards said it felt "surreal" when they finished.
"There was a great sense of achievement but our bodies really hurt," he said.
"About the only bit of my body that wasn't hurting was above the ears.
"I could barely stand up on Monday, and had little use of my hands. I can just about operate a keyboard today (Tuesday)."
Moore, a schoolteacher, was given Monday off by his boss.
Edwards hopes to use the tyre-flipping project to play a permanent role in promoting mental health.
"I know we pushed the mental health for men side of things and it is the silent killer for men," he said.
"But mental health is an issue for everyone. I hope to use this as a springboard for something more."