OMAHA — With her spot on the Tokyo-bound U.S. Olympic team surprisingly in jeopardy, swimmer Simone Manuel revealed Thursday she’d recently missed three weeks of critical training as she struggled with overtraining syndrome, a condition that she says drained her physically and mentally for months.

Manuel spoke at an emotional news conference not long after failing to qualify for the 100-meter freestyle finals at the U.S. Olympic swimming trials, a stunning result considering Manuel is the American record-holder and reigning Olympic champion in the event.

Her voice cracking at times, Manuel said she was proud that she was able to make it to these trials considering the symptoms she battled and the toll it took on her Olympic preparations.

“There’s the physical component but on top of that is the mental component,” said Manuel, who has one more chance to qualify for Team USA this week. “Like I said, I was going to practice and I didn’t want to be there because I knew I wasn’t at my best. That’s hard because I love this sport.”

She said she began showing symptoms in January and they got progressively worse over the ensuing weeks. She initially modified her training, but her performance in the pool continued to decline. In March, she and her coaches agreed Manuel needed a break.

“My body wasn’t doing what I knew it was capable of,” she said. “I had moments where I didn’t even want to go to the pool because I knew it was going to be bad. It was one of those moments where I felt relief because this was what I need to get to Olympic trials, but it also was hard because 11 weeks out from Olympic trials, I needed three weeks out of the water.”

Manuel, 24, said a variety of symptoms surfaced and made training difficult. Her heart rate would spike doing routine exercise and she said she suffered from insomnia, depression, loss of appetite and anxiety.

“I isolated myself from my family. My mom would ask me questions on the phone and I’d snap at her in ways that I typically wouldn’t,” she said.

She met with sports psychologists and doctors and was eventually diagnosed with overtraining syndrome, a condition she’d never heard of before. The National Center for Biotechnology Information defines it as “a maladapted response to excessive exercise without adequate rest, resulting in perturbations of multiple body systems (neurologic, endocrinologic, immunologic) coupled with mood changes.”

For Manuel, the symptoms became particularly pronounced as outside stressors intensified. She cited the pandemic, the year-long postponement of the Tokyo Games and the racial reckoning that roiled the country last year as contributing factors.

“Being a Black person in America played a part in it. This past year for the Black community has been brutal,” she said. “I can’t say that that wasn’t something that I saw, it’s not something that I could ignore. and it was just another factor that can influence you, mentally in a draining way.”

After winning gold in the 100-meter freestyle and the 4x100-meter medley relay and silver in both the 50-meter freestyle and the 4x100-meter freestyle relay at the 2016 Games, Manuel became one of the sport’s most recognizable stars. She was the first Black woman to win an individual swimming gold medal at an Olympics and especially in the past year has used her platform to speak out on issues of race and justice.

Three days after George Floyd was killed by a Minneapolis police officer last May, Manuel posted on Instagram: “Days feel heavy and long. It’s hard not to feel or think about the sadness and hatred that weighs heavily on me, my people, and this nation. I’m hurt. I’m tired. We’re hurt. We’re tired.”

But she continued her training. Manuel had won five golds at the 2017 World Championships and set a female record in 2019 with seven medals (four gold, three silver), stirring high expectations for Tokyo. And then the pandemic pushed the Olympics back a full year.

“To be focusing on the Olympics for a fifth year, mentally, is just hard,” she said. “Hard is an understatement. … Obviously it was pushed back for important reasons, but to focus on a goal like that for five years instead of four, is draining. You’re motivated still to go for it because it’s your dream. But at the same time, you’re trudging along at times.”

As she rested at home, Manuel skipped a Pro Series meet in Mission Viejo, Calif., passed on the media summit with reporters and missed three weeks of training. She returned to practice April 17 and had to work herself back into race shape with just two months before trials.

“I’m someone where I accomplish something and I’m always looking forward to the next thing. I don’t feel like I always sit back and appreciate what I’ve done. This is first time I showed up to a meet and before I even dove in and did a race, I was proud of myself,” she said.

The stakes here couldn’t be higher, and Manuel was unsure of what to expect this week. She scratched out of the 200 free, her coach said, to focus on her signature distances. But in Thursday evening’s 100 semifinal heat, she posted a time of 54.17, 0.02 of a second away from the final spot in the eight-person finals field.

“I know I did everything I possibly could to even be here — that makes me proud,” she said. “I continued to stay strong during this process, even when there were times when I wanted to give up.”

Manuel says she still plans to race in this week’s 50-meter free, which begins Saturday with preliminary heats.

“If your dream is important to you, you fight for it. This definitely was my biggest fight,” she said. “I hope that people can be proud of themselves with the work they put in before they even see their accomplishments come to fruition. Maybe it didn’t happen today but this isn’t the last time that you’re going to see me and this isn’t the last time that I’ll accomplish something in the pool. I’m confident in that.”

Dave Sheinin contributed to this report.