Until a ski pierced one of them last month, Winter Olympian Callum Watson had the best pair of lungs ever tested at the Australian Institute of Sport.
"I got my ski clipped by a competitor, found myself on the ground in the path of another skier," Watson said.
The 24-year-old, from Jindabyne in New South Wales, was racing a tight semi-final of the Australian cross-country sprint championships at Falls Creek when he fell in front of Swiss competitor Simon Hammer.
"His ski unfortunately managed to find its way through my chest, between the ribs and into my lung."
As he lay in shock, air gurgling from his side, a panicked Watson was quickly aided by fellow skiers who helped calm him.
By luck, a qualified trauma doctor was among the spectators and provided emergency assistance until Watson could be flown to Melbourne's Alfred Hospital.
There, he was seen by cardiothoracic surgeon Associate Professor Silvanna Marasco.
She initially hoped the lung may heal itself, but the two centimetre tear inflicted by the ski was too large.
"It was quite extensive, worse than I had imagined," Dr Marasco said.
"It became evident ... we would have to operate."
It was about that time that the hospital's deputy director of cardiothoracic surgery learnt that the lung she was fighting to save was far from ordinary.
An endurance cross-country skier who competes in gruelling races of 50 kilometres or more, Watson's lungs are perhaps his greatest asset.
Last year, he eclipsed Tour de France winner Cadel Evans's AIS record for the body's ability to process oxygen.
Known as a VO2 max test, athletes are hooked to breathing apparatus and pushed to the limit of their endurance, so scientists can measure oxygen levels in their blood.
Watson's AIS record of 89.6 ranks him among the world's elite.
In a bid to preserve this unique ability, Dr Marasco decided to modify her surgical approach - opting to only partially stick Watson's lung to his chest wall, for fear attaching its entirety could prevent it from fully expanding.
"I wasn't sure how that would affect lung capacity in someone at the extreme end of ability, so I chose not to do that," she said.
She undertook telescopic surgery instead of making an open incision and also took particular care to save as much lung tissue as possible, using staples to close the puncture wound.
At a check-up this week, she declared the operation a success.
"The wounds are healing well, the lung is fully expanded. I'm very happy with the chest X-ray appearance."Insurance battle looms for Watson
Watson's problems however are far from over.
Before leaving for Europe last year in preparation for the Sochi Olympics, the athlete says he had asked insurer NIB to pause his cover.
He said he discovered it had apparently been cancelled when he received a hefty bill for the helicopter which flew him to hospital.
Watson admitted he felt sick after learning about the situation while still in recovery.
"It's going to cost in excess of $12,000," he said.
"Knowing you're in a financial position that is going to be hard to get out of, that was really hard to take."
Like athletes from many fringe sports, he has worked part-time to fund his Olympic campaign.
The Australian winter was a chance for him to save money working as an instructor, so he could base himself in Sweden for the European season.
He is currently negotiating with the insurer.
In the meantime Australia's cross country skiing coach Finn Marsland has turned to crowd funding to help Watson meet his medical bills.
Mr Marsland believes Watson is capable of reaching the top level of World Cup skiing.
"We believe in him, he believes in him, we just need to give him that chance to prove to the rest of the world."
The campaign has so far raised almost half of its $20,000 target.
Watson said the support is both humbling and motivating.
"That means a lot to me and makes me want to push towards my goals more than ever."
He is now hopeful he can resume training in time to return to competition during the coming European season and ultimately, the 2018 Winter Olympics.