Australian swim star Ariarne Titmus said Friday that she was "feeling the buzz" for the first time since winning double Olympic gold in 2021 as she prepares for the world championships.

Titmus stunned American great Katie Ledecky to win the women's 200m and 400m freestyle at the Tokyo Games and she is aiming for more glory at the worlds, which begin Sunday in the Japanese city of Fukuoka.

Titmus's first race is set to be an epic 400 freestyle showdown featuring defending champion Ledecky and Canadian teen Summer McIntosh, who broke Titmus's world record earlier this year.

Titmus won four golds at last year's Commonwealth Games but this year's world championships are really getting her in the mood.

"I think this is probably the first time since the Olympics that I'm really feeling the buzz to race," she said.

"I think off the back of the Olympics, last year we had the Commonwealth Games and I didn't feel it as much as this year.

"I feel really raring to go, which is a nice feeling," she added.

The women's 400 freestyle, which sees Titmus, Ledecky and McIntosh go head to head for the first time since the Tokyo Olympics, takes place on the competition's opening night.

Titmus broke Ledecky's 400 freestyle world record last year but then saw McIntosh swim even faster at the Canadian trials in March, posting a time of 3min, 56.08sec.

Titmus cranked up the hype surrounding the race last month by questioning McIntosh's ability to handle the big occasion.

But she was full of praise for her 16-year-old rival on Friday, saying "she reminds me a lot of how I was at her age".

"I was completely fearless going up against Katie as a 16-, 17-year-old," said Titmus.

"I was never afraid to take it to her and I feel that Summer is exactly the same."

Titmus skipped last year's world championships in Budapest to focus on the Commonwealth Games.

She is set to compete in the 200, 400 and 800m freestyle events in Fukuoka but said the 400 was her "baby".

"I wish that I could watch from the outside," she said.

"I don't really remember seeing three women who have held a world record within 18 months together racing each other.

"I really hope we put on a good show," she added.

amk/lb