INDIANAPOLIS — Katie Ledecky took on the most grueling challenge of her swimming career and won three times.
This week might be only the warm-up.
The Maryland swimmer pulled away in the women's 1,500-meter freestyle final Saturday, winning in 15 minutes, 47.15 seconds, posting the fourth fastest time in world history and shattering the one of the oldest long-course championship records in the American book.
Janet Evans set the previous mark in March 1988 when she finished in 15:52.10. Twenty-five years, two months, three days later, Ledecky cut that time by nearly 5 full seconds to win another U.S. national title and give herself a chance to become the first American woman to swim the four longest freestyle events at a world championship.
"I'm very happy with that time and it's a good way to finish the meet," Ledecky said.
It can't get much better.
Ledecky competed in four races at the IUPUI Natatorium, winning national championships in the three longest events — the 400, 800 and 1,500 free — in astoundingly easy fashion.
She beat Sutton, one of her 2012 Olympic teammates, by 0.83 seconds in the 800 free Tuesday. Ledecky is the reigning Olympic gold medalist in that event.
She coated to another easy win, 21/2; seconds over Sutton in the 400 free Friday. Ledecky's time of 4:04.05 was a personal best and the third best in the world this year.
Then Saturday, she was under world-record pace for the first 600. Though she faded over the final 900, she still broke Evans' mark and produced the world's fastest time of the year just one day after Jazmin Carlin of Britain went 15:47.26. Ledecky was so far ahead when the race ended, she had time to look at the scoreboard, pump her fist and still watch the rest of the field trying to reach the wall. Chloe Sutton was second in 16:07.75, an astounding victory margin of 20.6 seconds.
The only minor blemish on an otherwise perfect week was Wednesday's second-place finish in the 200 free, finishing behind America's other teenage star, Missy Franklin, and ahead of another Olympic gold medalist, Shannon Vreeland.
What will Ledecky do for an encore?
Perhaps compete in the 200, 400, 800 and 1,500 free at Barcelona next month. The last American woman to try anything close was Shirley Babashoff, who competed in the 200, 400 and 800 at the 1975 worlds and the 1976 Olympics. The 1,500 was only added to the women's competition in 2001, and no American has tried to do all four on the world stage.
Now it's up to Ledecky and her coach, Bruce Gemmell, to decide.
"Mainly, it's just the schedule, making sure it's manageable," Ledecky said.
Ledecky's strong showing was just one chapter of a remarkable night that included record-breaking chases and incredible comebacks.
Natalie Coughlin, the 30-year-old three-time Olympian, barely won the 50 free title over a rising star nearly half her age. Coughlin finished in 24.97 seconds. Sixteen-year-old Simone Manuel was second in 25.01 seconds, breaking the national age group record for the second time in one day — a record Franklin had held.
"My start was not as good as it could be and because I knew that it wasn't as strong of a start, instead of doing 10 kicks, I only did eight," she said. "I was hoping to be faster, but I get to go to worlds, so that's good."
The winners of each event automatically qualify for the world championships next month.