Warning: Swimming world records to come

BEIJING -- So, will it take a world record to win the 100-meter backstroke?

"Probably, I would assume so," said Natalie Coughlin.

Coughlin, the reigning Olympic champion, is the existing holder of that mark (58.97 seconds, set at trials in Omaha) and hanging on to that status likely will be a difficult proposition at the Olympics. On Sunday night, four swimmers went under a minute in the prelims of the 100 back: Kirsty Coventry (59.00), Reiko Nakamura (59.36), Anastasia Zueva (59.61) and Coughlin (59.69).

The top 16 make the semifinals, and the other American in the field, Margaret Hoelzer, had the seventh-fastest time, in 1:00.13.

"In prelims, you don't want to kill yourself. You want to swim as fast as possible to get into the semifinal with a little bit left in the tank," Coughlin said. "The 100 back has been the quickest progressive event in swimming over the past year. I was actually expecting more 59s than just four. But I think other people were doing the same strategy of trying to conserve for tomorrow."

-- Lisa Dillman

Photo: Natalie Coughlin competes in a women's 100M backstroke heat. Credit: Julian A. Wainwright / EPA