When Jordan Miller walks onto the gym floor, there’s a good chance one of two mantras is blaring into his ears: “Gimme More,” or when he’s feeling especially feisty, “Work Bitch.”

He has a 700-song playlist, but it always comes back to Britney. That’s the case with Miller outside of the gym, too.

Miller is the creator of Breathe Heavy, the popular Britney Spears fan site. He says he was the first person to write the term “Free Britney” in a 2009 post criticizing the pop star’s court-approved conservatorship.

He’s also a CrossFit fanatic, competing in six CrossFit Opens and multiple competitions around Las Vegas. In his last Open, he placed in the top 10 percent worldwide, out of roughly 300,000 competitors.

On this week’s edition of “The Sports Kiki,” I spoke with Miller about his unwavering Britney fandom, and decorated athletic career. Growing up, Miller was a champion gymnast, and trained under the legendary Olympian Vitale Scherbo. He credits his years on the mat for instilling him with confidence and determination.

“I was essentially one of, if not the first person to speak out publicly against a very unjust situation that Britney’s been in, and is currently stuck in,” he said. “I’m thinking, ‘How could this famous iconic pop star go on tour, put out albums, do interviews, raise her children, but be deemed by the courts as someone who’s incompetent?’ It just did not make sense, and I was very against it right away.”

For the last 11 years, Miller has been working tirelessly to raise awareness about his pop idol’s legal imprisonment. The conservatory agreement put Spears’ father, Jamie, in control of her career and finances.

The legally binding accord is typically used when courts appoint individuals to care for elderly people who can no longer care for themselves.

Twelve years later, the “Free Britney” movement has exploded, thanks to a fresh New York Times documentary about the saga. In November, Spears’ attorney said the singer won’t perform as long as her dad remains in charge of her estate. Last week, a judge delivered a modest victory to Spears, giving a third party equal power to her father in managing her finances.

Miller’s advocacy once prompted the ire of Jamie himself. In 2009, the elder Spears called Miller, who was a teenager at the time, and threatened to “destroy his ass.” But Miller didn’t acquiesce. He kept Breathe Heavy online, and never heard from Spears’ attorneys again.

“I think when you’re a big fan of somebody, you can set the noise aside,” he said. “Back then, it was really convenient to tear her down, because it was also lucrative to do so. The gravitational pull of that was too great for anyone to want to stop and actually think, ‘Are we doing major damage to this woman?’”

As a closeted gay teenager, Miller identified with Spears’ desire for liberation.

Growing up in Las Vegas, Miller competed three times at the Junior Olympic National Championships, making it into the finals on vault. Along the way, he developed his love for Britney.

To Miller, and millions of other gay boys, Spears symbolized sexual liberation. When she took over the halls in her schoolgirl outfit, she was walking for all of the boys who were afraid to show a little more of themselves.

“Women are oftentimes criticized and sometimes can’t publicly be themselves,” Miller said. “I think gay men growing up have to also face some kind of aspect like that — they can’t be their true selves. Then it becomes very liberating once you face it, and I think pop queens like Britney, there’s a whole parallel to that.”

As gay men, we have to be strong, and in adulthood, Miller says he’s most attracted to Spears’ fortitude.

“When you’re a kid, you don’t even have a thought process,” he said. “You’re just like, ‘Queen! I love her! She’s in the schoolgirl outfits, she’s so cool.’ And now, as an adult, and especially having intimately covered every single detail about her conservatorship, I have grown to truly respect her resilience and her strength, because what she is going through now is no joke.”

Today, Breathe Heavy is one of the go-to places for Britney fans to celebrate and commiserate. It attracts around 300,000 visitors per month, and boasts just under 70,000 members. For eight years, Miller worked on Breathe Heavy full-time. The community is his lifeblood.

When Miller apples himself, he likes to go all-in. It’s a trait he picked up from Scherbo, who won six of eight events for the USSR at the 1992 Summer Olympics.

That’s why CrossFit is now Miller’s outlet of choice. Just a few years ago, he was completely new to the sport, and somewhat weary of its cult-like reputation. But now, he’s a proud evangelist. Miller trains five or six times per week.

While the six-pack is nice, Miller most enjoys the mental release.

“I was at a point in my life when I was in a — no pun intended — ‘toxic relationship,’” he said. “And I kind of let myself go a lot, and was really unhealthy, and I just decided one day I’m never going to be this person ever again.”

Miller reshaped his body and spirit, with Britney serving as his guide and inspiration. Despite facing an avalanche of ridiculously misogynistic criticism, and subsequently losing legal ownership of her person, there she is — posting on Instagram and trying to live her life.

It’s a reminder that no matter what life throws at you, you’ve gotta do work.

“What she’s trying to show the world is that she’s still that girl,” Miller said. “She’s still strong, and I just have a respect for that. It’s not easy to do that.”

Click here to check out this episode of our Outsports podcast, “The Sports Kiki.” You can also subscribe to the show on Apple’s Podcast page as well as on Google Podcasts, and wherever you’ll find Outsports podcasts.

You can follow Jordan Miller on Instagram, “@itsjordanmillerbitch.