INDIANAPOLIS — For Katie Ledecky, it seems like burnout doesn’t exist.

Of course, there are times when it all gets a bit monotonous, staring at that black line on the bottom of the pool, swimming endless laps without anything on the line.

Still, 12 years after she burst onto the scene with a surprise gold medal at the London Olympics, Ledecky continues to find ways to enjoy swimming.

Times may not be fast. But the ultimate reward is staying at the top year after year, Olympics after Olympics, even as other swimmers struggle with the mental and physical demands of a grueling sport that only offers fulfillment once every four years.

Ledecky is one of the most consistent swimmers in history

“I pride myself on that consistency,” said the 27-year-old Ledecky. “I challenge myself to be consistent. Yeah, I mean, sometimes it can be hard to feel like you’re not having a breakthrough. But to actually be consistent, that’s what I’m really happy about. I’ve learned to just really enjoy every day of practice and take advantage of every moment and just appreciate that I’ve been able to have such a long career, stay injury-free, stay relatively healthy and do this for so many years.”

Ledecky, perhaps the greatest freestyle swimmer ever, is heading to the Olympics for the fourth time in a familiar role.

A gold medal favorite. The center of so much attention. The template for continued excellence.

“What a huge influence,” said fellow American swimmer Erin Gemmell, who has admired Ledecky her entire life and will join her as an Olympic teammate. “I don’t think I would actually be here if it wasn’t for her.”

Gemmell’s father used to be Ledecky’s coach. Young Erin once dressed up as Ledecky for Halloween. They spent so much time together at the pool, Gemmell has a unique perspective on Ledecky’s dull brilliance.

“It’s really special to be able to be so close to someone who is so inspiring, and to see the daily work that they put into it,” Gemmell said. “It makes it more attainable in a way to be so close. It makes them a lot more human.”

Ledecky is no longer so dominant

Ledecky isn’t as dominant as she once was, but she’s certainly the swimmer to beat in the two longest freestyle events, the 800 and 1,500 meters. She already has six individual gold medals, the most of any female swimmer in Olympic history.

“Every athlete, as they get older, needs to learn new ways of setting goals and evaluating results,” Ledecky said.

In many ways, she’s still driven by her very first Summer Games, where she burst onto the scene at age 15 with a gold medal in the 800-meter freestyle. She offers more perspective on that experience in her new book, “Just Add Water, My Swimming Life.”

“I wanted to get back to that level, prove that I wasn’t just a one-hit wonder,” Ledecky said. “At the same time, I reminded myself that anything more than that is just the icing on the cake, the icing on the cake, because I never thought I would make it to that one Olympics.”

After all these years, after all those times she stood on the highest podium, she still feels that way.

“That’s the perspective that I’ve been able to keep and that’s what keeps me focused and makes me enjoy the sport so much, my teammates and the people around me,” Ledecky said.

She is definitely an old soul.

Even as a teenager, young swimmers looked up to Ledecky.

“I was definitely a bad kid,” Gemmell said, grinning. “But I think she was just so welcoming to a little 7-year-old fan. When I think about it, she was only a sophomore in high school at the time. I think if someone had acted like that to me when I was a sophomore in high school, I would have felt really weird. But she was kind and welcoming with everything.”

Eight years ago in Rio de Janeiro, Ledecky delivered one of the greatest performances in swimming history.

She took gold in the 200, 400 and 800 meter freestyle, setting two world records (the 1500 wasn’t an Olympic event for women yet, or she would have undoubtedly won that too). And to top it all off, she helped the US to a gold medal in the 4×200 meter freestyle relay with a time more than a second faster than anyone in the final.

Ledecky is not a favorite in the shorter freestyle races

Five years later in Tokyo, the rest of the world began to catch up with her in the shorter races. For the first time, she was beaten in an individual race when Australia’s Ariarne Titmus took gold in the 400. Ledecky didn’t even make the podium in the 200, having to settle for fifth.

Ledecky has no plans to swim the 200-meter freestyle in Paris, despite winning that event at the U.S. Olympic trials. She is a clear underdog in the 400-meter freestyle, where Titmus and Canadian phenom Summer McIntosh appear to have the upper hand. McIntosh could even give Ledecky a run for gold in the 800-meter freestyle — an event Ledecky has won at the last three Olympics — after beating her at a low level this year.

As always, Ledecky shakes off her rivals. She’s always looking inward, looking for ways to improve, and that month-long gap between the trials and the Olympics is her favorite time of all. She can retreat to the anonymity of the training pool, where she feels most at home.

“My goals are not to be the first person to do this, to be the first person to do that and to join this person and this person as the only ones who have done this,” Ledecky said. “My goals are very time-oriented and split-oriented and technically-oriented.”

It may not sound that exciting to outsiders, but it gives Ledecky a feeling that she still has the same as it did twelve years ago, when she first went to the Olympics as a 15-year-old girl.

Burn-out?

No chance.

— Paul Newberry, AP National Writer