The London 2012 gold medallist finished in a time of 3 min 58.86sec to secure her third win of the competition in Irvine, California, after claiming victory in the 800m and 200m freestyle earlier in the week, and become the first swimmer since Janet Evans to hold the world record in the 400m, 800m and 1500m freestyle events.

"[The world record] was on my mind, but I didn't let it overtake me today," Ledecky said.

"Whatever happened, happened.

"I think that's why it worked out that way.

"I knew I could go a best time this year, and I was only seven-tenths of a second off the world record, so I just let it go.

"I knew if I could be three-tenths faster here and there, I could beat that record."

Ledecky had already recorded the fastest time in the world this year in the preliminaries with 3:59.89 - seven-hundredths of a second off her own US record, and 0.74 off the former world record of 3:59.15, set by Italy's Federica Pellegrini at the 2009 World Championships in Rome.

Katie Ledecky is now the first swimmer since Janet Evans to hold the world record in the 400m, 800m and 1500m freestyle events ©Getty Images


In the finals, she distanced herself from the pack from the start of the race and was as far as 1.7 seconds ahead of world record pace through 250m, before holding on to a 38-hundredths-of-a-second margin in the final lap.

Cierra Runge, who came in behind Ledecky in the 800m freestyle, finished second again in 4:04.67, while Leah Smith was third in 4:06.28.

There was also gold on the day for fellow London 2012 champions Missy Franklin and Matt Grevers in the women's and men's 100m backstroke respectively, while Olympic medallist Jessica Hardy and world bronze medallist Micah Lawrence tied for the women's 100m breaststroke national title.

Elsewhere, Cody Miller won the men's 100m breaststroke and Michael McBroom claimed gold in the men's 400m freestyle.

Nine athletes competing at the National Championships have now officially been added to the US squad for the Pan Pacific Championships, including the most decorated Olympian of all time Michael Phelps.

Contact the writer of this story at [email protected]


Related stories
June 2014: Phelps ends Santa Clara meet with third as he builds towards Rio 2016
April 2014: Phelps comes out of retirement as he eyes Rio 2016 glory