Katie Ledecky exits the pool after winning the women’s 800-meter freestyle and setting a new world record. (Stephen Spillman/Associated Press)

Katie Ledecky can’t seem to stop breaking world records: The 18-year-old swimmer re-set her own mark in the women’s 800-meter freestyle Sunday at a Pro Swim Series event in Austin, finishing in a time of 8 minutes 6.68 seconds.

That time broke her previous record set in August at FINA’s world championships by seven-tenths of a second, and places her more than seven seconds ahead of the event’s next fastest performer. Ledecky now owns the top eight performances in history and nine of the 10 top times.

“It was exciting,” said Ledecky, who told reporters she could hear the crowd at about the midway point of the race. “It’s always exciting when you can get pushed along by a crowd like this in Austin.”

It was the fourth time she’s broken the world record in the event in the past four years, and her 11th world mark of her short international career, which began at the 2012 London Olympics when she upset former world-record holder Rebecca Adlington of Great Britain in the 800 free. Her first world record came a year later at the Barcelona World Championships in the 1,500, and, until Sunday, her most recent was set at the Kazan World Championships in August, when she lowered the 800 mark on the final day of competition by a stunning 3.61 seconds.

“I was feeling good going into it; I knew I had some good swims this weekend,” Ledecky said. “Whenever I get going like that I get into a good rhythm with my freestyle. My stroke just feels good the whole weekend once I have one or two really good freestyle swims.”

In Austin, Ledecky also won the 200 and 400 freestyle events, which she also won in Kazan along with the 800 and 1,500 distances. She is the favorite to win the 200, 400 and 800 at the Rio Olympics, and could factor in the 100 free as well, an event in which she finished second Friday behind Swedish Olympic sprinter Sarah Sjostrom. No female swimmer in history has contested the 100 through 800 at an Olympics.

Prior to arriving in Texas, Ledecky had been altitude training at the Olympic Training Center in Colorado Springs, where she arrived on New Year’s Day. The Bethesda native graduated from Stone Ridge in the spring, but deferred her enrollment at Stanford, where she is committed to swim, until after Rio. She took two classes in the fall as a visiting student at Georgetown, but decided to focus on her swimming during what would have been the spring semester.

While breaking a world record in-season is rare, it’s actually the third time Ledecky has done so. She broke the 800 and 1,500 in June 2014, also coming down from altitude training.