It's not just Ian Thorpe who has turned to the demanding medley to break the monotony of winning gold medals.

"Lethal" Leisel Jones wants to inflict more pain on her already suffering rivals by following Thorpe's lead and adding the 400 metres individual medley to her packed national swimming titles campaign starting at the Sydney Aquatic Centre this weekend.

While Thorpe will be dipping his toe in the 200m IM at the eight-day national titles which start on Saturday, champion breaststroker Jones will likewise will be debuting in the 400m IM, an event described by "Thorpedo" as "the hardest event in the world".

Not content with dominating women's breaststroke by the tender age of 17, the Queenslander said the new program kept her fresh in the countdown to the world titles in Spain in July and the 2004 Athens Games.

The national titles double as the selection trials for the world titles where Jones will look to improve on the 100m breaststroke silver she picked up at the 2001 event at Japan.

Jones will undertake a gruelling schedule at the national titles, tackling the 50m, 100m and 200m breaststroke plus the 400m IM and only dropped the 200m IM because it clashed with earlier events.

Just as Thorpe took up the medley this year to give himself a new challenge after dominating men's freestyle, Jones said the medley would stop her swimming becoming stale.

"I suppose it will come to a point where I don't like it anymore - I want to get the best in before that happens, hopefully that's a long time away," she said.

"I do have a limited time. I don't want to waste a second."

And again like Thorpe, Jones was not putting herself under any pressure to perform in her new swimming passion.

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