Two devastating defeats in two days have left former champion Laure Manaudou wondering whether she should quit the swimming competition midway through.

"I'm asking myself if it's worth continuing. I don't even have the desire to swim anymore," Manaudou told France-2 television yesterday after placing seventh in the 100-metre backstroke. "It's tough finishing seventh or eighth."

On Monday, Manaudou finished eighth – or last – in the 400 freestyle, more than eight seconds slower than the winner, Britain's Rebecca Adlington.

Manaudou was slated to race twice more: the 200 back tomorrow and the 400 medley relay on Friday.

These games have been a sharp contrast from Manaudou's breakthrough four years ago in Athens, when aged just 17, she brought home France's first swimming gold since Jean Boiteux in 1952, in the 400 free. She also won a silver in the 800 free and a bronze in 100 back.

In 2005, Manaudou became the 400 free world champion, a title she defended in 2007. In between, she broke the 18-year-old world record of Janet Evans, and then improved on her own mark again just three months later.