IRVINE, California (AP) — Michael Phelps has always fed off adversity. Not that the most decorated Olympian has faced much in the pool.

Until now.

Phelps lost all four of his races at the recent US national championships. Hardly shocking for a guy who is four months out of retirement, but somewhat surprising for someone who already owns 53 national titles.

Phelps, though, is focused on his long-term goal of competing in a fifth Olympics in 2016.

“I’d rather lose all the national championships that I swim in as long as I’m ready for the big races,” he said after the meet in Southern California.

He’ll get a taste of some big races during next week’s Pan Pacific Championships in Australia. Phelps qualified in the 100-metre butterfly and 200 individual medley. The combined results from nationals and Pan Pacs, featuring the US, Australia, Japan, Canada and Brazil, decide the US team for next year’s World Championships.

Phelps headed Down Under knowing that if he wants to win in Rio de Janeiro, he’s got to once again commit to staring at the black line on the bottom of a pool. Those hours of training helped drive him into retirement two years ago.

“I have no choice,” he said. “If I want to be where I want to be, I know what I have to do. With having a year-and-a-half off and maybe not really going as hard as I probably should have at some of the parts during the year, it shows.”

At 29, Phelps came to that realisation on his own rather than needing the usual prodding from coach Bob Bowman or his mother.

His California losses included two second-place finishes, but his times were encouraging. He swam 51.30 seconds in the 100 butterfly and 1:56.55 in the 200 individual medley. Both were third-fastest in the world this year.