WHEN ultramarathon runner Lee Pratt saw a young bike rider struggling on Pilbeam Dr during Rockhampton's Challenge the Mountain, there was no question he'd give up the race to help.

Mr Pratt isn't sure what was wrong with the bike, but he offered to carry it as the two men walked the remaining 3km of the gruelling climb together.

The unrelenting 5km timed race pits runners and cyclists against Mount Archer's 10 per cent gradient.

For Mr Pratt, it was just a training run.

He's used to tough endurance races in the Sunshine Coast hinterland and Blue Mountains, and regularly trains on Mount Archer's walking trails.

It's the first time Mr Pratt has done the annual mountain race, but he said the decision to help a fellow competitor was easy.

Challenge the Mountain president Sharon Kearney said seeing the images of people helping each other throughout the race gave her goosebumps.

"There are so many facets to the event and it brings out the best in everybody. It's just a beautiful event," she said.