INDIANAPOLIS – During the eight months Caeleb Dressel spent not swimming, he was surprised by the things he came to miss. Some were simple, like blowing bubbles in the water or the feel of his toes on the grip tape of the starting blocks. But he also missed the chlorine – a swimmer’s nemesis – and the dry skin that comes with hours spent in the pool.

“I missed every part of it and that’s how I knew I was ready to get back. Because I didn’t need to – I wanted to,” Dressel, 26, said.

For several years, Dressel, a seven-time Olympic gold medallist, reigned as the best sprinter in the world. But in June 2022, he abruptly withdrew midway through the world championships because of an undisclosed health issue and disappeared from the sport and the spotlight.

Outside of a social media post in September, he had not discussed his absence publicly until last week, when he returned to elite swimming competition at the United States national championships.

Dressel’s performance reflected his long hiatus from the pool. His preliminary swims in the 50m and the 100m freestyle, events he won at the Tokyo Games and in which he holds the US record, were too slow to make the finals. His best finish in four events was third in the 50m butterfly, not good enough to qualify for the upcoming world championships in Japan.

For the first time since Dressel emerged as a new young star in men’s swimming in 2016, as Michael Phelps was preparing to retire, he will not be part of the US team for the biggest international competition of 2023. But not long ago, Dressel was not even sure he would get back in the water again, so this meet carried a significance beyond his results.

“I always had a smile on my face actually racing,” he said. “There is a difference between racing scared because you don’t want to embarrass yourself and then actually enjoying racing. And I haven’t had that enjoyment for quite some time, so it was nice having it back.”

His goal is to regain his form in time to qualify for Paris 2024. While this meet underscored that he has a long road back physically, he said the mental part will be more important.

Dressel did not disclose why he withdrew from the world championships in Budapest, Hungary, but he said that stepping away from the sport was a necessity.

“The easiest way to put it, my body kept score,” he said. “There were a lot of things I shoved down and all came boiling up, so I didn’t really have a choice.”

Anthony Nesty, Dressel’s coach with Gator Swim Club in Florida, cited the extra pressure on Dressel as the face of US men’s swimming and said the sprinter needed time to escape it and focus on himself. Nesty said Dressel’s therapist was part of Dressel’s decision that he was ready to return to the sport earlier in 2023.

“Mental health is a serious issue, and everybody deals with it differently. Sometimes it takes time to heal from that,” Nesty said.

In recent years, elite athletes have become more open about the mental health challenges that can come with the pressures of their sports.

Towards the end of his swimming career, Phelps began talking about the anxiety and depression he experienced as he became the most decorated Olympian of all time, while gymnast Simone Biles and tennis player Naomi Osaka have both taken time off from their sports to focus on their well-being.

In June, swimmer Lydia Jacoby shared for the first time that she experienced depression after winning gold in the 100m breaststroke at the Tokyo Games.

Jacoby said she struggled with her sudden vault to stardom at age 17 and with seeing swimming as a career instead of a passion, but “hit the deny, deny, deny button” about her depression until she fell short of qualifying for the world championships in 2022.

She took a break from training last summer and has been working with a therapist. After she made this year’s US worlds team with a second-place finish in the 100m breaststroke, Jacoby said, she is starting to feel like the swimmer she was in Tokyo.

The 52-person US team that took shape without Dressel included some familiar faces – Katie Ledecky swam her third-fastest time in the 800m free on her way to her sixth world championships – as well as several new ones.

Thomas Heilman, a 16-year-old from Virginia, became the youngest male swimmer to qualify for a US worlds team since Phelps after placing second in both the 100m and 200m butterfly events. Heilman, who said he watches YouTube videos of Phelps and Dressel’s old races to pump himself up, swam next to Dressel for the first time in the 100m fly final. After Dressel finished behind him, in a tie for fifth, he put his arm around the youngster and congratulated him as they walked off the deck together.

Dressel resumed training in late February with three practices a week, and he began a full workload of eight practices a week only in early May. But while he lost some of his strength and fitness during his layoff, he said he also gained some peace.

He said he is now able to sit on his front porch with his wife, Meghan, “and not think of a million things I need to be doing, or what I did wrong in practice, or why I thought I did bad in Tokyo, or why I thought 2019 was terrible.”

He drew on that new mindset during the first night of competition in Indianapolis. In the 100m free, Dressel’s seed time of 47.67 seconds came from his lead-off leg in a relay at the 2022 world championships before he withdrew – a direct measure of his competitive form before his hiatus. His prelims swim during the nationals was nearly two seconds slower, qualifying him only for the “C” final, a bonus heat at the end of the prime-time programme in which he could not medal or qualify for international competition.

With nothing on the line, he could have simply scratched the race. But after starting that night sitting in the stands with Meghan and his parents, he slipped downstairs to warm up. By the time he stepped up on the blocks, the crowd had thinned out. He took his mark and raced, and then looked up at the scoreboard to see a time that would place him 19th in the event.

He hoisted himself out of the pool, smiling, and headed to the diving well to cool down, not a winner but still in the water. NYTIMES