The world's longest winter ultramarathon is a daunting prospect for even the toughest and fittest extreme sports enthusiast.

Brisbane bike mechanic Troy Szczurkowski, 44, crossed snow and glaciers by fat bike and foot as part of the 1,000-mile (1,609-kilometre) Iditarod Trail Invitational.

He was one of only a handful to finish this year's event.

Back at home now three months on, his body is still recovering but his mind is already looking forward to next year's challenge.

The Iditarod Invitational is no ordinary bike race — it is a hard slog where competitors have to painstakingly walk their bike, at times even carry it to continue the journey.

At points along the road the ice was treacherous, with one rider falling through to icy waters below.

Troy Szczurkowski (left) during the 1,609-kilometre Iditarod Trail Invitational. ( Supplied: Troy Szczurkowski )

"It's a very, very frightening thing to happen," Mr Szczurkowski said.

"You fall through the ice, very fast running water. As soon as you're in the ice you've got to get out quick and try and get your clothing dry — clock is ticking once that happens."

Mr Szczurkowski was one of only six competitors in a group of 26 who rode bikes to finish this year's event.

"It was absolutely fabulous," Mr Szczurkowski said.

"This was the winter that I've wanted for many years."

'Your body goes through a lot of torture'

The journey was a beautiful one, complete with white snow-capped trees, stunning dusks and the Northern Lights, Mr Szczurkowski said.

And although riding alone for much of the race, the father of one said he was never lonely.

"No, I always welcome the silence," he said.

"It's the kind of thing that's very hard to find nowadays with so much white noise."

"I feel most relaxed out there in that environment being totally self - sufficient. I think that's where it starts to turn switches on in my brain that I like."

Every moment was consumed with planning, aiming to get to the next checkpoint where he had organised to replenish food.

Mr Szczurkowski slept outdoors, melted snow for drinking water and carried food for a week at a time. ( Supplied: Troy Szczurkowski )

"In this situation, mental is far more important than physical," Mr Szczurkowski said.

"If you've got the right gear and you think about things well enough and you have a good back up plan you can make it through. You've just got to be patient and adapt to the situation."

But it was not easy.

In the freezing cold temperatures he suffered the early stages of frostbite and was hit with the stomach bug that was going around.

He was forced to spend two days recuperating.

He drained his blisters by running a wick through them and was forced to cut away parts of his boot to use chemical heatwarmers for relief.

"Your body goes through a lot of torture in those cold temperatures. You don't get a lot of relief from it."

There were other problems too.

The Iditarod route in Alaska. ( Supplied: Iditarod Trail Committee )

He arrived at a checkpoint one Saturday to find the person he had organised to provide a drop bag of provisions for the next week had gone snow machining with a friend.

Faced with no food, Mr Szczurkowski was forced to take the food of other competitors who had been scratched.

Queensland family watched on via GPS

More than 11,333km away at their home in Daisy Hill, south of Brisbane, Mr Szczurkowski's wife, Nyree, and daughter, Tabby, 11, were watching a blue dot which represented his GPS coordinates.

They were praying for the best.

"It was a roller coaster ride through through the whole race," Ms Szczurkowski said.

"There were frostbite injuries, people had gone through the ice some of the guys were getting their own evacs out because they were severely dehydrated and sick from a stomach bug that was going through — that was really neve-racking getting that information out.

Mr Szczurkowski back at home in Brisbane with wife, Nyree. ( ABC News: Leonie Mellor )

"You have to rely on your faith in what he's organised and what he's prepared.

"He was ready for the cold temperatures. I had to fall back on the knowledge that he had the gear, he had the knowledge of what he was going into and that he would be OK."

February was the second time Szczurkowski had taken on and finished the Iditarod - he previously completed the 350-mile race (563km) to qualify for this year's longer event.

He said it was also unlikely to be the last time on the Alaskan track.

"There's always that excitement of what's next, what am I aiming for next," he said

"I'd like to go back of course, that's always on the cards."

Determination a common trait in athletes, expert says

Mr Szczurkowski said he never doubted he would finish this year's event.

"No, no — there's always a way you can make it forward even if it's at half speed," he said.

"You set out to do something like that then you've got to see it through."

The jubilation of crossing the finish line was the sweetest feeling of all.

"The people that make it through, I think they all share that common mentality of always looking for solutions, not necessarily finding a wall and going: 'well, OK I'm done'," Mr Szczurkowski said.

"It's: 'Let's workshop it, how can we find a solution around it'."

Mr Szczurkowski (left), with two other competitors at the event in Alaska. ( Supplied: Troy Szczurkowski )

That determination is a common trait, according to Queensland University of Technology psychologist Robert Schweitzer.

Professor Schweitzer has studied the motivation behind extreme sports.

He said most athletes were not irresponsible risk-takers but highly trained individuals seeking a life-changing experience.

It exposed them to profound fears relating to risk, dread and even death, and made them feel alive, in a society which was becoming more risk averse.

"It is a way of experiencing themselves which is quite different to the way they experience themselves in any other endeavour," Professor Schweitzer said.

"They talk about the preparation but while they are engaged in the sport, time is described as standing still. The pleasure associated with the activity is described in terms of transcending, very traditional kinds of pleasures and it is really a way of experiencing themselves in the way that is not achieved in any other way."