Just six months ago, Tom Dean, a remarkably fit professional athlete, couldn't walk up the stairs without wheezing .
The 21-year-old swimmer had contracted coronavirus for a second time, but in this instance, his symptoms were much more concerning.
“I had six or seven weeks out during an Olympic year which is essentially unheard of,” he said.
“When I was sitting in my flat in isolation, Olympic gold seemed like a million miles off."
Dean talks about having to rebuild his strength post-infection
Dean, however, produced the performance of his life in the final of the men’s 200 metres freestyle on Tuesday. He clocked a national record time of one minute and 44.22 seconds and became the first British man to win an Olympic freestyle title in 113 years.
It's a far cry from Dean wondering if he would even make the flight to Japan.
“I think I was one of the first athletes in any British Olympic sport to contract Covid twice in such a short space of time, so there were quite a few question marks around it.
Mum Jacquie Hughes says Tom Dean's coaches recognised something in him when he was 11 or 12
“I’m thinking ‘how am I going to be able to recover from this in time to get a solid block of work under my belt before we start tapering for Olympic trials?’" he said.
He credits his coach David McNulty for lifting him when he was at his lowest. McNulty kept him "grounded", Dean said, gradually building his fitness back up.
"It’s a dream come true to wear Olympic gold around my neck,” Dean said.
It's been a meteoric rise for Dean. A few weeks after taking up swimming at his local club in Maidenhead, aged eight, he remembers being on holiday and watching in awe as Michael Phelps won a record eight titles at Beijing 2008.
Dean said: “When you get to the Games, you understand what a feat it was to secure as many Olympic medals as he did.”
Ten years after first watching Phelps, Dean burst on to the professional swimming scene. He claimed his first solo senior international medal at the European Short Course Championships.
Since, he's racked up the medals, including four European golds.
In his quest to for an Olympic gold, Dean put his mechanical engineering studies at the University of Bath on hold.
When asked whether he will resume his studies in September, he pointed to his gold medal and said: “I think this kind of changes my plans slightly, but we’ll see.”