Olympic American swimmer Katie Hoff has split with her long-time coach and mentor Paul Yetter; she'll be working with Bob Bowman, Michael Phelps' coach.

Hoff, 19, went into the Beijing Games as favourite but had mixed fortunes winning just a silver medal and two bronze medals.

She finished second behind British Rebecca Adlington in the 400 metres freestyle, then bronze in the 400 IM and 800 metres freestyle relay.