A freak accident at an altitude training camp in Switzerland saw the 27-year-old Launceston athlete suffer a stress fracture in his anklebone.

After two weeks of physical pain and mental anguish, Harris opted to tackle the 42-kilometre event at the IAAF titles in London and made it just over halfway before being forced to pull out.

“I got an MRI on the Monday before the race which confirmed the bad news,” Harris told The Examiner from England.

“I had to chat to the medical team from St. Moritz and their advice was to not run as I risked doing permanent damage.

“But it was my decision at the end of the day as it was my spot and there was no one else that was a reserve or anything.” 

After a decade-long running career featuring numerous state titles and national bronze medals over 3000 metres, half-marathon and marathon, Harris said his decision to race was “easy”.

“I had to at least start the race. A DNF in my eyes is a much better result than a DNS, given the risk of never getting this opportunity again. 

“I had an awful week psychologically before the race as I was constantly worried it wasn't going to respond well on race day or that I'd do that serious damage.”

Despite suffering “severe pain”, the Kings Meadows High School teacher joined his Australian teammates in London and said he felt OK lining up on the start line at the city's iconic Tower Bridge.

“I was pretty happy with the warm-up and how it got going with the adrenaline of the moment and I felt relatively normal in the early stages, just a little cautious,” Harris said.

With heat, wind and numerous corners adding to his discomfort, Harris began running on the outside of his foot in an attempt to keep the pressure off the injury. 

“I had stopped to nearly a walk by the 24km mark and it was then that the decision to stop was a simple one. Physically I had no more, I just decided I'd run past my mates one last time and then finish where my sister (Callie) was standing.

“I stopped at 28km, pulled my singlet off – which is tradition for a DNF in the Australian kit in a mararthon – and got a ride back to the finish on the motorbike. 

“I don’t feel like I did any permanent damage out there, I stopped before that became a reality, but I gave it a go and didn’t die wondering.” 

Harris said his only disappointment was the “one bad step” in St. Moritz that caused him to land awkwardly and sustain the injury.

“Everything else I'm fine with. I’m looking forward to enjoying the rest of this experience now, and I'll have to have several months off to get the foot right.”

Fellow Launceston-born runner Milly Clark contested the women’s marathon at the championships, finishing 24th in a season’s best time of 2:35.27.

“We are the sum of all experiences - good and bad,” reflected the 28-year-old Sydney-based Rio Olympian the following day. 

“For reasons perhaps out of my control unfortunately the body did not match the mind. I gave everything I had and while I wake with heavy legs and a heavy heart, I am genuinely grateful to have been given the chance to add another experience to my growing sum. I appreciate the amazing support from everyone to get me here.”

Clark said her national teammates Jess Trengove, of South Australia (who finished ninth), and Victorian Sinead Diver (20th) “deserve every bit of praise for their incredible runs and pure grit”.