Ian Thorpe admitted he'd made significant changes to his training program under new coach Tracey Menzies after failing to fire again at the national swimming championships in Sydney.

For the third time at the titles, the Thorpedo won a gold medal but failed to fire, dead-heating with Olympic relay team mate Ashley Callus for the 100m freestyle title, both swimmers stopping the clock at 49.07s.

His form at the meet has put the spotlight on his new partnership with Menzies, forged after Thorpe's highly publicised split from childhood coach Doug Frost six months ago.

But while Thorpe admits to being a "little frustrated" with his form during the meet he has refused to criticise Menzies saying he's been more than satisfied with his preparation.

Instead, the 20-year-old said he'd always expected it may take 12 months for the new relationship to start paying dividends.

"I'm confident enough in the program that I'm in and the way that I've raced that things are progressing well," he said.

"I've made a significant change in the way that I train and the way that I do things and in doing that it's going to take a little bit of time to adjust.

"When I first made this change I didn't think I'd be swimming as well or see the benefits of it for probably 12 months into it."

Thorpe said he was confident he would be swimming well by the Barcelona world championships in July.

"I'll have trained with Tracey for about 12 months or almost 12 months when it comes to that stage," he said.

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