ESSEN, Germany -- Double world champion Kate Ziegler of the United States broke her own 800-meter freestyle short-course world record on Sunday -- her third world record in 48 hours.

Ziegler, 19, set a world record over 800 meters in the 25-meter pool with a time of 8:08, according to the Web site of the SG Essen swimming club.

She beat the mark of 8:09.68 that she had recorded on Friday in the middle of a 1,500-meter race.

On Friday, Ziegler had first lowered the record in the 800, beating the mark of 8:11.25 held by France's Laure Manaudou, en route to a record in the 1,500 of 15:32.90, below Manaudou's 15:42.39.

Ziegler won the gold medal over both distances at the world championships this year in Melbourne.

Manaudou's 800 mark was recorded on Dec. 9, 2005 in Italy and the 1,500 record set on Nov. 20, 2004 in France.