GWANGJU, South Korea — In her first individual race since illness knocked her out of two events this week at the world swimming championships, Katie Ledecky posted the second-fastest qualifying time in the 800-meter freestyle on Friday, behind her American teammate Leah Smith.
Ledecky, a two-time Olympic champion in the event who owns the 22 best times in its history, closed fast over the final 150 meters to nearly catch Smith, who was in an adjoining lane. Ledecky touched the wall in 8 minutes 17.42 seconds, almost 13 seconds slower than her world record and a blink behind Smith’s 8:17.23.
Ledecky appeared sapped by the effort, proceeding straight to the warm-down pool without stopping to talk to reporters.
The final on Saturday will cap a turbulent week for Ledecky, one of the sport’s most dominant performers, and give her a chance to salvage one gold medal from a meet where she was favored to win at least three.
Ledecky, 22, came to South Korea expecting to pick up where she left off at the world championships in Budapest, Hungary, two years ago, when she collected six medals, including five golds, in the freestyle events.
But before this meet started, she was ambushed by a mysterious ailment, and then, in her first final here, the 400-meter freestyle on Sunday, she was passed on the final lap by Ariarne Titmus, an 18-year-old Australian.
So fierce is Ledecky with a lead, the way she lost was like watching a gazelle prey on a leopard.
The next day, Ledecky returned to the water for the 1,500-meter freestyle preliminaries, and even though she recorded the top time, she knew something was seriously amiss.
“I got to the 1,100 point of the 1,500, and I almost stopped and got out,” Ledecky said Thursday, adding, “I just kind of blanked out the rest of the race and tried to finish it, got over to the coaches and medical staff and told them, ‘I’m not myself.’”
Ledecky retreated from public view for nearly three days. She withdrew from the final of the 1,500, her best event, scratched from the 200-meter freestyle and surfaced only to participate in an abbreviated training session.
Ledecky returned to competition Thursday as a member of the United States women’s 4×200-meter freestyle relay. She helped the quartet, which also included Simone Manuel, Melanie Margalis and Katie McLaughlin, to an American record and a silver medal. With a time of 7:41.87, the Americans surpassed the existing world record, set in 2009 by China, but were beaten by Australia, which was timed in 7:41.50.
Swimming the second leg, Ledecky clocked a 1:54.61, which was the third-fastest split in the relay final, behind Titmus’s leadoff 1:54.27 for Australia and Penny Oleksiak’s 1:54.36 anchor leg for Canada.
“That went a lot better than I expected,” said Ledecky, who had to clear one last obstacle on her way to the 800. She had to provide a urine sample for doping control, which wasn’t easy given that she had been dehydrated, at times severely, all week.
“We don’t know exactly what caused this all,” Ledecky said, “but just feeling the effects of dehydration, loss of appetite, lightheadedness — just a lot of different things, to be honest — it just kind of created a perfect storm.”