Not so long ago, Australian superstar Kaylee McKeown could have claimed all six backstroke world records in both the long course and short course pools.

He has just two left after American backstroke star Regan Smith won the short course 200 meters record at the Aquatic Swimming World Cup in Singapore.

Smith, whom McKeown beat to gold in the 100m and 200m backstroke at the Paris Olympics, finished in 1 minute, 58.83 seconds, falling 0.11 seconds behind the previous mark, held by l ‘Australian.

Australian Iona Anderson finished third in 2:01.98.

Smith had already lowered his 100m backstroke mark further with a 54.27 the day before, marking a hugely successful meet.

“We had so much fun in those three stops,” Smith told the media during the World Cup series.

“It’s been great. It’s a World Cup, it’s so much fun and I want to keep doing it for years to come.”

McKeown had competed on the first day of the first leg of the three-stage World Cup in Shanghai.

There, she beat Smith in the 50m backstroke with a new World Cup peak time of 25.36, but withdrew from competition to prioritize her mental health.

“I would like to thank World Aquatics for the opportunity to come and race at the World Cups, it has been so much fun here in Shanghai,” McKeown wrote on Instagram in October.

“Prioritizing my mental health, I decided to cut my experience short.

“As an athlete, it is very important to listen to your heart and know when enough is enough.

“It’s time for a well-deserved break.”

Last year, McKeown broke several world records and won the women’s overall title at the World Cup series.

However, despite his superb performance in Paris, McKeown was back in action soon after, competing in the Australian Short Course National Championships in September.

“I was going a bit crazy, sitting at home,” McKeown said in Adelaide.

“So I decided to go back to two weeks and a few weeks ago and just increase the sessions.”

It turned out to be a good move, as she broke the almost five-year-old world record for the 100m short course backstroke, coming 0.33 shy of compatriot Minna Atherton’s mark.

Then she didn’t commit to competing in the Short Course World Championships in December, saying she wouldn’t put any pressure on herself.

McKeown has been named in the squad of 24 for the Championships, which will be held in Budapest, which includes 10 Olympians from Paris and eight debutants.

Short course swimming takes place in a 25 meter pool, which allows for more turns and faster times than a 50m long course pool, which is the size of the pool in which the Olympics are held .

McKeown now holds the non-Olympic world records in the 50m backstroke and 200m backstroke in the long course, but after winning the year’s two major prizes in Paris, she is unlikely to be too phased by losing his records.

Smith, on the other hand, who broke McKeown’s 100m long course mark before the Olympics, was optimistic.

“I want to go to the short course world championships and have as much fun as I have here.

“I think life is too short to take things like that seriously. I had so much fun and that’s what swimming should be about. And so I think my goal at the short course world championships is to swim fast and enjoy it.

Elsewhere in Singapore, Australian Isaac Cooper won the men’s 50m backstroke in 22.61, Mo Johnson was third in the 800m, while Brittany Castelluzzo won the 200m butterfly and was third in the 200m freestyle.

Many other Paris Olympians were also in action, including French hero Léon Marchand, who swept the medley events, breaking the world record in the 200m IM.

Meanwhile, American Kate Douglass won four events, including breaking the world record in the 200m breaststroke by edging out Smith for the overall World Cup title and a check for $US100,000 ($152,000).