World champion Leisel Jones says she is feeling fresher than ever and is gunning to break her own world marks in the 100m and 200m breaststroke.

The Australian, who is almost untouchable in the events, is using the world swimming championships this month as a springboard to the Beijing Olympics, and wants to cement her supremacy ahead of the 2008 showpiece.

"Being the defending champion (in both events) is confidence building and I know I've done the hard work. I'm looking forward to the pressure and atmosphere," the 21-year-old told the Herald Sun.

"I'm so excited about swimming in Melbourne.

"It will be the last stepping stone before next year's Beijing Olympics and most people will want to get the best out of themselves."

She said home support for the main swimming events could drive her to break more world records.

"The crowds will make a difference," Jones said.

"There will be a real energetic spirit that, hopefully, will lift performances.

"World records are personal bests for me. I jump into the pool every day wanting to break personal bests. You're always trying to get the best out of yourself. I'm fully tapered and fresh."

But while Jones, who has been on the Australian team since she was 14, is geared up for the Beijing Olympics, she is uncertain about whether she will still be around for London in 2012.

"I'm so undecided about after Beijing. It's so up in the air," she was quoted as saying by The Melbourne Age newspaper.

"Beijing is still a year and a half away and that seems like ages, so for me, I think I'll be relaxing for quite a while after Beijing and then see if I want to get back in and do the journey to London.

"Another four years is a long, long time, so for now I'll just worry about Beijing and be looking forward to an Olympic experience for once."

US record-holder Jessica Hardy is seen as Jones's main threat, along with Hardy's teammate Tara Kirk.

The world swimming championships officially open on Saturday with synchronized swimming, although the main events do not start until March 25.

(China Daily via AFP March 15, 2007)