WASHINGTON >> The first lady arrives without fuss or fanfare, although her armored sport utility vehicle and Secret Service detail set her apart from the usual Lululemon-clad throng.

Michelle Obama is here to work out. She has come to put on professional cycling shoes, clip in to a stationary bicycle and engage in the steamy, heart-pounding, candlelit fitness obsession known as SoulCycle.

“I love it when my girls join me for a little SoulCycle,” Obama said of her daughters in a video posted to Twitter last year, when she talked about her favorite ways of staying active with her family. “We all are in the dark, moving to the beat on the bikes. We love it.”

That was Obama’s first public admission of her SoulCycle habit, and since then the White House has guarded details about it not quite as vigilantly as it does the nuclear codes. Obama’s East Wing staff declined to comment for this story.

But over the past two years, as the Tribeca-based fitness chain has expanded its footprint in the nation’s capital, the first lady has made stealthy trips to at least three SoulCycle studios in downtown Washington — one in the West End near Georgetown, another on 14th Street and yet another in Mount Vernon Square.

Obama arranges for private sessions, held outside normal class hours and away from security risks and photo opportunities, with friends, aides and sometimes her daughters.

She is not the only political figure to seek sweaty solace at the trendy, high-end cycling boutique, where 45-minute classes average $28 ($32 if you are riding in New York, New Jersey or Connecticut) and the walls are emblazoned with slogans like “inhale intention and exhale expectation.”

Chelsea Clinton announced last week that she would hold a fundraiser for her mother’s presidential campaign on Jan. 27 at SoulCycle’s flagship Tribeca studio, where donors will pay $2,700 for a “premium reserved bike” to ride with Chelsea and her “pack,” and pose for a photograph with her. The younger Clinton is a longtime devotee of SoulCycle, where she and former President George W. Bush’s daughter Jenna Bush Hager have been spotted cycling in the same crowded New York classes.

For Obama, who has made healthy eating and fitness a policy focus and a personal brand, SoulCycle is the rare workout that takes her outside the confines of the White House and into what the chain’s disciples like to call a “cardio dance party.”

SoulCycle is known for its style of studio cycling, which combines the intensive cardio of a spin session, core-toning moves such as the “tap back” — standing on the bike and pedaling while touching one’s derrière to the seat behind — and the meditative aura of a yoga class. It unfolds in a nightclub-like atmosphere: a dark room with candles burning (some with SoulCycle’s signature grapefruit scent), rhythmic music pulsing and meticulously groomed instructors sporting skulls and flywheels on their outfits while shouting instructions and inspirational mantras from an elevated bike in front.

Megan Kelly, an instructor whose sessions Michelle Obama is known to have frequented, shouts, “Yes, you can! … Yes, you can!” — a mantra from President Barack Obama’s political campaigns — to get her riders through steep climbs and fast sprints. Wearing a sleeveless black T-shirt that says “Spiritual Gangster” and black spandex capri pants, as well as a full face of makeup and a manicure, Kelly packs her playlist with hip-hop music like “Stand Up” by Ludacris and “Power” by Kanye West.

Kelly declined to comment for this article, in line with a confidentiality policy that prevents the company from discussing any of its clients, said Gabby Etrog Cohen, a spokeswoman.

But the company has become close to the first lady. Its founders and instructors have been invited to holiday parties at the White House, said Julie Rice, who co-founded the chain in 2006. “We’re enormous fans of her,” she said of Obama.

Rice said riders, and public figures like Obama, sought out the sessions for their “sanctuary”-like atmosphere.

“It definitely delivers a workout — you’re guaranteed to have results with your body — but it’s also an escape,” Rice said in an interview. Riders “know it’s safe and anonymous, and they can actually engage in a group activity as part of a community.”

Not that Obama gets complete anonymity. She is routinely spotted by riders and passers-by when she is arriving or leaving one of the three studios for her private classes.

“Just spotted my girl Michelle at Soul Cycle!!” @kayjulers wrote on Twitter in September, adding Obama’s Twitter handle, @FLOTUS, which stands for first lady of the United States.

Jodi Richardson, who estimates she rides three or four times a week at the Mount Vernon Square studio, said she “freaked out” on a recent Monday night when she walked out of what she thought was the final class of the night and happened upon Obama, who was striding in for a session.

“Nobody else was freaking out,” said Richardson, 30, a lobbyist. “I’m a Republican, and I still freaked out. I mean, it’s the first lady within feet of you.”

Richardson said she had run to the front desk to check the bike manifest and see if she could reserve a bike to pedal with the first lady.

“They grabbed the clipboard and were like, ‘No! This is a private class,’ ” she said.