William Corlett completes 'Project Impossible', runs 200km from Launceston to Hobart

It was 3pm the next day when he crossed the finish line; 30 hours had passed, but he had gone the distance.

He was relieved to complete the full 200 kilometres.

"When we finished I was just like 'perfect, get me home, let's have an ice bath'," said Mr Corlett.

"Reflecting on it now, I'm happy that I finished the 200 kms."

The Katoomba-raised runner completed the massive journey on February 22 for a fundraiser he named Project Impossible.

He said the run was challenging towards the end.

"I walked into there thinking, very naively, that it was gonna be a lot easier than it was. I'd been given a plan by my coach... I got 60 kms in not following the plan, and then realised I should start following the plan," he said.

"That took me to about 140 kms, and then it started getting tough. And we made it to about 170 kms, and I just lost the gas out of the tank, and we had to walk the last 30 kilometres."

For that final stretch, his friend Benjamin Lanyon, from Blackheath, got out and walked as well to encourage Mr Corlett to the finish line.

"We just decided that we had to finish, that was the goal. No matter what it took, we were gonna finish," said Mr Corlett.

For an extra burst of inspiration, he also got a call from long-distance runner Nedd Brockmann.

"It was great. He's a really nice bloke obviously, he spoke to me on terms as if we were equals which was really nice... the fact that he took time out of his schedule to make that video, it just made it seem like it was a bit more worthwhile," said Mr Corlett.

The inspiration was welcome, as there were some unexpected challenges to overcome throughout the 200km run.

"During the night it felt freezing, it felt absolutely freezing when it got to [3] o'clock in the morning... the cold was something we definitely weren't 100 per cent prepared for," he said.

"A mistake was we weren't checking my feet often enough... when we finished we took all the bandages off my feet, and I had massive blisters, toenails coming off.

"This trip, it was all a bit of a learning experience is how we're looking on it."

Alec Gleeson, from Woodford, and Thomas Murphy, from Katoomba, were also part of the supporting crew.

Mr Corlett has raised more than $11,000 for Lifeline, not including money raised from t-shirt sales.

"I've in hindsight realised you don't call Lifeline when you're 'bad' enough, you call them so you never get 'bad' enough. You call them so you get that support along the way. And that's really the message that we're trying to preach," said Mr Corlett.

He had videographers with him, and plans to screen a video at Mount Vic Flicks within the coming months. He also plans to enter the UTA 100 in May as his next challenge.

You can donate to Mr Corlett's fundraiser through the Project Impossible page on Lifeline's website: https://fundraise.lifeline.org.au/fundraisers/williamcorlett.