Michael Phelps and Katie Hoff bolstered their Beijing Olympic bids with victories on Wednesday at the US Olympic swimming trials.

Hoff won the 200m freestyle and 200m medley in impressive style to take the number of individual events on her Beijing dance card so far to four.

Katie Hoff reacts after winning the women's 200m individual medley at the US Olympic swimming trials in Omaha, Nebraska, on Wednesday. Reuters

Phelps posted the second-fastest time in history in the 200m butterfly - 11-hundredths of a second outside his own world record, to secure his spot in a third individual event at the Olympics.

"I just don't think I took the race out like I should have," Phelps said. "I was too relaxed the first 50, to be honest. I definitely won't make that mistake again.

"I secured my spot on the Olympic team, that's the important thing," said Phelps, who will be aiming in China to break Mark Spitz's record of seven gold medals at one Olympics.

He was also pleased to note that runner-up Gil Stovall's time of 1:53.86 made him the second man, apart from Phelps, to break 1:54 in the event.

Phelps, who was an early entry in nine events for the trials, continued to refine his program.

After posting a 100m freestyle heat time of 47.92 - his first swim under 48 seconds - he withdrew from the semifinals.

The heat swim, he said, accomplished his mission of securing consideration for the 4x100m free relay team, and dropping out insured he didn't jeopardize his stronger events.

He also confirmed he wouldn't swim the 200m backstroke, leaving the 200m individual medley and 100m butterfly as his remaining individual events this week.

Should he qualify in those on schedule, he can expect to have five individual events and three relays to swim in Beijing.

"Our program is looking pretty good," his coach Bob Bowman said. "It's shaping up nicely."

Hoff is also eyeing a multiple medal Beijing bid.

Like Phelps she cemented her spot on the Olympic team with a 400m medley victory in world-record time last Sunday.

The 19-year-old won the 400m freestyle on Monday, and on Wednesday notched two national records as she racked up two more victories.

Her 1:55.88 in the 200m freestyle was the third-fastest in history, as she held off a fast-closing Allison Schmitt (1:55.92).

Forty-five mintues later she won the 200m medley with the second-fastest time ever (2:09.71), with Natalie Coughlin second in 2:10.32.

The youngest athlete on the US delegation to Athens in 2004 at 15, Hoff will now be one of the brightest US stars.

If she qualifies in her two remaining events, the 100m and 800m freestyles, she'll more than live up to her reputation as the female Phelps.

"That was a hard double," Phelps said of Hoff's races on Wednesday. "And she swam both races perfectly. She's swimming like Katie swims."

"This night was the big night for me," Hoff said. "Having it over is a relief."

Wednesday marked the first day that the trials failed to produce a world record, after six fell in the first three days.

But the men's 100m freestyle heats and semifinals produced a bevy of brilliant performances.

Jason Lezak topped the semifinal times, touching in 47.58.

Garrett Weber-Gale, who was fastest in the morning with a time of 47.78, was third-quickest in the semis, clocking 48.35 behind the 48.29 of Nick Brunelli.

(AFP via China Daily July 3, 2008)