Titmus, McKeown carry Australian hopes in bid to topple US at Olympics

Australia's formidable swim team heads for the Olympics this week headlined by two superstars of the sport in Ariarne Titmus and Kaylee McKeown as they look to snap a 68-year hoodoo against arch-rivals the United States.

The pool squad was whittled down after six intense days of trials that culminated in Brisbane on Saturday, with bettering their haul from Tokyo three years ago the immediate target.

"I'm excited, really excited, we have a great group of athletes," said head coach Rohan Taylor, who steered them to nine gold and 21 medals overall in Japan behind only the all-conquering Americans.

Australia last beat the United States on the medal table at the 1956 Olympics in Melbourne, but Taylor is bullish they can mount a serious challenge again.

"This team is going to give it a good shake," he told reporters.

"But the Americans, there's a reason they haven't been beaten since 1956 -- they're just extremely competent when it comes to the Olympics, this is where they step up.

"They have got the depth, they've got the numbers, they've got the experience.

"We're going to go there and do everything we can to create an environment for these (Australian) athletes, first and foremost, to do their best."

Their aspirations rest heavily on the shoulders of Titmus and McKeown, along with Mollie O'Callaghan and their relay teams.

Titmus returns to the Olympic stage as defending 200m and 400m freestyle champion, with the 800m, where she claimed silver in Japan, also on the agenda.

McKeown is defending her 100m and 200m backstroke titles and world records. She will also swim the 200m medley after clocking the fastest time since the 2016 Rio Olympics last week.

The 400m free is already being touted as the "race of the century" with Titmus once again facing American great Katie Ledecky, who she upset in Tokyo, and Canadian phenomenon Summer McIntosh also in the mix.

Titmus is favourite on paper, owning the world record and clocking the second quickest time ever last week.

She is also the 200m world record holder after smashing O'Callaghan's previous mark at the trials, but is philosophical about her prospects.

"The world of swimming never stops and there's always people who are going to be swimming fast," said the 23-year-old. "You can never just expect that gold medals are going to come your way."

McKeown, 22, appears untouchable in the backstroke, boasting the top seven 100m times ever and three of the top five over 200m.

O'Callaghan is down for seven events -- three of them individual although she could drop the 100m backstroke.

She won two gold and a bronze in Tokyo as a heats swimmer in relay events, but has since become a dominant force in her own right, clinching the 100-200m freestyle double at the 2023 world championships, setting a world record in the process.

That 200m mark fell to Titmus in Brisbane with O'Callaghan, 20, admitting to being a bundle of nerves under the pressure of being world record holder.