Running around Union Glacier in sub-zero temperatures, his feet sinking into soft snow, Colin Wright found it hard to focus on anything but the enormity of the task ahead.
He strained his eyes against the blinding white scenery, trying to spot the next pit stop alongside the Ellsworth Mountains in the Antarctic.
"It's hard to gauge distance in that part of the world because everything is white, so you're running and you think the next aid station is close but it's actually 7km away," Mr Wright said.
"You're always looking for something firmer to run on, so it was hard to keep mentally focused on that while trying to take in the scenery."
Back in Perth after tackling the Antarctic Ice Marathon last month, Mr Wright admits he is just about ready to hang up his running shoes.
He battled -20C temperatures to finish the gruelling 42.2km race in five hours and 42 minutes alongside about 50 competitors from around the world.
The Floreat resident was stuck in Antarctica for an extra five days after the event because of bad weather - but it made the "trip of a lifetime even more special".
"The Antarctica is a spectacular location and I had more of a chance to take it in," Mr Wright said. The competitors went cross-country skiing and were taken on excursions while waiting for the weather to clear.
Mr Wright has raised almost $21,000 for three WA charities - the Harry Perkins Institute of Medical Research, the Children's Leukaemia and Cancer Research Foundation and Breast Cancer Care WA - through the event.