Kyle Chalmers is vowing to extend his storied Olympic career while revealing he had three cortisone injections in six weeks before his silver medal in Tokyo.
Chalmers was touched out by American Caleb Dressel by just 0.06 seconds in a thrilling 100-metres final on Thursday.
Chalmers' silver follows his gold in the high-profile race at the 2016 Rio Games.
"I am really happy with how I executed my own performance, there is nothing else I could have done better," he said.
Chalmers unleashed his trademark late surge, coming from third at the turn to draw level with Dressel.
But the American rallied to win in 47.02 seconds followed by Chalmers (47.08) and Russia's Kliment Kolisnikov (47.44).
Chalmers' time equalled his personal best and came after a torrid time of injury and self-discovery following his surprise Rio triumph.
"Obviously after Rio, I kind of felt untouchable, I was this young kid who had stood up and won," he said.
"And then the reality sunk in and it was back to normal and I didn't swim too well there for a while."
But entering 2020, Chalmers was hitting his straps. Then, the Olympics were postponed because of the coronavirus pandemic.
After a month or so off, Chalmers returned to training.
"I got back in the pool and probably tried to rush my training a bit, had the shoulder blow-out," he said.
Chalmers had a dozen cortisone and two platelet-rich plasma injections and surgery last November.
"I swim through a lot of pain," he said.
"After trials (in mid-June) I had to have two cortisones in my left shoulder and one in my right.
"So you kind of feel like you're getting that two steps forward, one step backwards type thing.
"There has been plenty of moments where I have thought that it wasn't possible for me to be here at an Olympic Games, let alone in a final and doing my best time again.
"So I have to be really, really grateful and content with that."
The Adelaide-based flyer was seeking to become the first Australian to claim double gold in 100 free.
Jon Henricks (1956), John Devitt (1960) and Michael Wenden (1968) are Australia's other 100m freestyle champions while only four swimmers in Olympic history have won back-to-back titles.
Chalmers, who also picked up bronze medals in the 4x100 and 4x200 freestyle relays, has committed to racing the International Swimming League (ISL) starting late next month.
Then, some rest and repair before preparing for the 2024 Paris Olympics.
"There will be some time to reflect and to hopefully take some time off after ISL this year," he said.
"'I would say there's a fair chance that I'll be back in three years' time."
Australian Associated Press