Australian triathlon star Pete Jacobs admits the whips are cracking with a month left until his Hawaiian Ironman world title defence.

The 32-year-old has not won this season and the pressure is building ahead of the October 12 championship at Kona on Hawaii's Big Island.

Jacobs has had to balance the rigours of his Hawaii buildup with the need for a big result at Sunday's inaugural Ironman 70.3 Sunshine Coast race.

A 70.3 triathlon is a 1.9km swim, 90km cycle and 21.1km run - half the distances of the Hawaiian race.

"I've been feeling a bit flat this week so I've backed off a little and, the last few days, I've got a burning feeling that I really want to win on Sunday," Jacobs said at Friday's media conference.

"(That) will show I'm on for the good race at Kona.

"I've been more down than up this year, so I really want to win this race to show I'm in good form."

Jacobs' wife Jaimielle, who will also race on Sunday, spoke of the need for his sleep and diet to be spot-on.

"If Pete has his day sleeps, you know he's going to have a good race," she said.

"If he's getting his nanna naps, he's right.

"If he's getting the right meat from the farmers' markets, it means his guts will be good.

"As a wife in bed, you want your husband's guts to be good."

Jacobs will face plenty of strong opposition on Sunday, with fellow Hawaiian competitor Clayton Fettell and Tim Berkel well-credentialled in long-course racing.

Three-time world Olympic-distance champion Pete Robertson has stepped up to long-course triathlons after a break from the sport and will be the wildcard in the men's elite race.

New Zealander Gina Crawford is the women's favourite, with her toughest opposition expected to come from Japanese triathlete Kiyomi Niwata.