The 19-year-old defending Olympic champion led from the start and smashed her own world record.

That completed a sweep of golds following her earlier wins in the 200 and 400 metres freestyle.

“I’ve hit all my goals this past week… I just wanted to lay it all out there,” Ledecky said after her final race in Rio.

“I have to wait another four years to have this moment and I just wanted to enjoy it all and put my very best swim out there.”

The rare Olympic swimming treble has only been achieved by one other woman, American Debbie Meyer in 1968.

Ledecky said Meyer had sent her a video message of support via her mother before the race.

“I try not to think about the history of it much, but just to be mentioned in the same sentence as her is incredible,” she said. (Euronews)