The schoolgirl, in Baltimore in a training group trained with Michael Phelps, was already before the 2004 Olympic Games in Athens as an exceptional talent on both layers distances. However lacked the then 15-year-olds have the necessary routine to already in Athens in the medal fight miteinzugreifen. About 400 meters layers, she reached the finals and not suffered after the semi race a cycle of collapse.
Among the swimming World Championships 2005 in Montreal then traveled matured Katie Hoff to the competitions and won the 200 meters and 400 meters before Kirsty Coventry from Zimbabwe. In addition, she was with the U.S. 4×200 meters relay on freestyle relay world champion.
In the World Aquatics Championships 2007 in Melbourne, she could both the 200 meters title on plant and equipment and also over 400 meters assets successfully defend. The World Cup title on assets swam 400 meters world record with them. Moreover, she could also take this World Cup with the American 4×200 meters relay on triumph.
In July 2008, when the U.S. Olympic Trials, she joined with excellent form and was their favorite roles more than expectations. They qualified for five events at the Olympic Sommerpielen 2008 in Beijing. About 400 meters assets, their parade route, they pushed the old world record by Stephanie Rice by 34 hundredths of 04:31,12 minutes. At the Olympic Games but Rice won the world back and Hoff had about 400 meters layers satisfied with third place. About 400 meters freestyle she won the silver medal.