USA’s Katie Ledecky sets new Olympic record in 800m freestyle heats

• Ledecky betters Rebecca Adlington’s mark, set in Beijing 2008
• Time of 8:12.86 nearly seven seconds faster than anyone else
• Follow all the latest in our Rio 2016 live blog

Katie Ledecky has set an Olympic record with the fastest time in the 800m freestyle heats.

The 19-year-old American swam the 16-length event in 8min 12.86sec seconds Thursday, bettering the old mark of 8:14.10 set by Rebecca Adlington of Britain in 2008.