Reborn world champion Cameron McEvoy has literally rewritten the book on short-distance swimming and his tactics are working so well he's planning a Brisbane Olympics tilt as a 38-year-old.

Last year in Japan, McEvoy became the oldest Australian to win a swimming world championship.

His 50m freestyle time of 21.06 seconds broke a 14-year national record.

It capped the 29-year-old's stunning resurgence after all but quitting the sport following a lacklustre Tokyo 2021 campaign.

He will defend the title in Doha next week.

McEvoy will be the star of a Dolphins squad missing most of its household names when the swimming component of the World Aquatic Championships begins on Sunday.

While others preferred to skip the meet and instead focus on July's Olympics, the physics and mathematics whiz saw it as a primary source of evidence in his radical experiment that has turned the sport on its head.

"It's significantly extended the longevity of my career," McEvoy said of the revolutionary training routine he introduced last year.

It's a remarkable turnaround for an athlete who didn't compete at all in 2022 and had his 100m Olympic dreams dashed six years before that, when 18-year-old roommate Kyle Chalmers slashed his way to Rio gold.

McEvoy puts it down to finally turning a "gut feel" into a legitimate thesis that has seen him drop his weekly training distance to just 3km from what was once 70km as a 13-year-old.

Rather than the traditional taper, McEvoy borrowed from track and cycling sprinters to instead train less, hit a high intensity, sustain it and build again from that.

"My whole career was 11 and a half months of 30km a week, massive volume, tapering, and it's the first time you hit intensity all year," the Gold Coast product said.

"So the first event you feel great, then throughout the week you feel s*****r.

"For a very long time I always had questions about how we train.

"I didn't agree with a large majority of it, but I hadn't spent the time to really dive in.

"The choice was to move on or give it a go, and if it doesn't work then I've got closure.

"The new approach has basically sparked the sprinting world to move towards what I'm doing."

Younger swimmers in McEvoy's squad are naturally enjoying the sustainable workloads, and it's opened up new possibilities for the man himself.

"It takes the pressure off a lot," he said.

"I can do the Olympics, worlds, then have 12 months exploring other stuff, and come back.

"And I've got tonnes of side quests I want to do … train for 100m track sprinting and see how low I can go, the world street lifting competition."