Poolside in cowboy hat, heels, and nothing in between, Isolde Worsham interrupts water aerobics at the Glen Eden Sun Club, a 150-acre nudist resort in Corona, California. “All of you with new hips? Let’s modify the flutter kicks.”

The 800 members of Glen Eden plan their days around the pool. “Sags less,” one member tells me. They sun with their legs spread. They make unflinching eye contact, and avoid the cactus garden after dark. Edenites can spot “cottontails,” or new nudists (think tan lines), at a glance.

But by and large, the cottontails arriving at Glen Eden (and other nudist clubs around the country) need their flutter kicks modified. Nudism’s devotees point to millennials as the generation that can re-invigorate their ranks. But for reasons financial and ideological, the same young people who have perfected the belfie (butt selfie) and share their birth vlogs are resisting the call.

At the Lost Bikini Grill, three members of Colorado’s Mountain Air Ranch—170 residents, 10 miles of low-visibility hiking trails—grumble about geriatricians and Gen Z. (“I roll my eyes at gender stuff once,” one member says, “and suddenly Grandma’s a bigot.”) At the Lake Como Family Nudist Resort, outside Tampa, a line forms for the elder-care pool lift. At a reception desk in Pasco County, Florida—the self-proclaimed nudist capital of the world—one doleful man seated on his towel (the nudist’s crucial accessory) offers this about his peers: “Well, things are getting wrinkly.”

“Your greatest challenge,” Gary Mussell told a crowd of nudists at Arizona’s Shangri La Ranch in July, “is to attract younger people.” The speech marked Mussell’s farewell to a two-year term as president of the western division of the American Association for Nude Recreation (A.A.N.R.), the country’s largest nudist-advocacy group, established in November 1931.

A.A.N.R. collects dues from more than 30,000 members across 260 clubs in North America, Mexico, and the Caribbean. If those clubs don’t spice up their act, Mussell warned at Shangri La, “I fear there won’t be anyone left to care if A.A.N.R. celebrates its 100th birthday or not.”

The Hippie Hippie Shake

In the late 1960s and 70s, a generation cast off its chains—and its clothes. Most were artists, hippies, lefties. Some just hated getting dressed.

Calling themselves naturists, they found their way to “free beaches”—day-trip destinations with high dunes and no rules. The beaches were a smash hit, but popularity brought scrutiny; by the Reagan years, a day in the nude could mean a visit to the courthouse. The naturists needed a new home base.

Before, many naturists had turned up their noses at A.A.N.R.’s nudist clubs, gated communities with strict rules of conduct (no booze, no touching), and calisthenics galore. But with beaches fading out, what choice did they have? Twenty- and thirtysomethings poured in. They brought their kids. They brought their politics too.

Nude pétanque! (The French version of bocce.)

Calisthenics made way for nude yoga, nude therapy, nude magic-mushroom trips. In pools—the hub of the American nudist camp—new members talked leftism.

The naturists turned a pre-war German health-craze import into an ideology fit for the flower child: nudity as rejection of shame and class, a prerequisite to equal, honest, true community. Magazines from those years are packed with fervor. From The Magazine of Natural Living, spring 1987: “Discard the rags of shame!”

“All of you with new hips? Let’s modify the flutter kicks.”

Today, the average A.A.N.R. West member is over 60. He won’t provide numbers, but Jeff Baldassare, the “textiled” (non-nudist) communications director for A.A.N.R., said the overall demographics look “no different.”

Like their members, the clubs have aged. Pickleball—a version of tennis that is easier on the knees, shoulders, and heart—abounds. So do water aerobics and sewing groups. Zumba is a guaranteed hit. When a 21-year-old reporter arrives nude on the scene, her age makes her the odd woman out at each address.

“We’re on the cusp of real change,” Mussell tells me. At 73, he has a white beard and is as bare on Zoom as in real life. Mussell calls himself nudism’s Cassandra.

“What will happen first?” he says. “Will we die out, or will the millennials grow up and join us? The movement is on the cusp of something. I won’t live long enough to find out what it is—and most people high up won’t say it out loud.” (Baldassare: “We have no issues. Things are great.”)

“Millennials are prudes,” retired masseuse Carrie Adams tells me over tacos at Glen Eden Sun Club. “Being naked on the Internet? Fine. Being naked in front of 100 strangers? Harder.”

A Different Kind of Nudity

Today, nudity—that is, staged, sexual nudity—is everywhere. Lena Dunham’s full-frontals on the HBO show Girls, which caused a stir in 2012, have become the norm. (See, more recently, Game of Thrones or Bridgerton.) With billions of yearly visits, Pornhub, which launched in 2007, is currently America’s eighth-most-popular Web site. Enough millennial and Gen Z women have ditched their bras to send Victoria’s Secret spiraling, and sexting carried those two generations through quarantine.

But there are strings attached.

Millennials, and to a larger extent Gen Z–ers, are at once more progressive and less liberal than any recent generation. They free the nipple, ferment their own ale, elect A.O.C. (Overheard from a rare thirtysomething at Mountain Air Ranch: “Where can I get something gluten-free and vegan?”)

Millennials call themselves “sex positive,” but they have less sex and fewer partners than their parents did. They are body positive, too, all about girlboss-style empowerment. But who invented the Instagram filter?

A.A.N.R.’s everyday, nonsexual, by-definition-unflattering nudity? “Yeah,” a 24-year-old tells me, turning down an invite to a Glen Eden Sun research trip. “I would rather die.”

A nudist crowd relaxes in Florida, photographed by Weegee in the 1950s.

Among the few young nudists out there, A.A.N.R. clubs are unaffordable and passé. Millennials are the best-educated, least financially stable demographic in three generations. “Boomers could work two days a week at a grocery store and buy a house at whatever club they wanted,” a 26-year-old sometime nudist tells me. “We have student loans.”

So the cost-free option is back in vogue: free beaches and a return to low-key naturism. “It’s all a cycle,” Mussell says. “Kids these days want nudity today, paragliding tomorrow. The movement doesn’t interest them yet. The fun does. They’re just like we were on the beaches. The question is—will our timing line up?”

It was certainly the fun, not the movement, that seemed the focal point of the Florida Young Naturists’ (F.Y.N.) 2021 Re-Ignite Bash earlier this month. The event drew some 200 18-to-35-year-olds, who pitched their tents in the fields outside Lake Como for four nights.

Three times a year, the F.Y.N.—titan of a slew of new youth-focused naturist groups largely independent of A.A.N.R.—throws a festival wherever it can. On the agenda at its most recent event: throat singing, a “fear-release-empowerment hypnosis” class, and three kinds of belly dancing. There was also fire dancing, drumming, drug trips, and sex. Singles outnumbered families.

“Kids these days want nudity today, paragliding tomorrow.”

“Our quiet hours,” snipped a Como receptionist at the nearby A.A.N.R. resort one night, “start at 11.”

“This is why I avoid the A.A.N.R. clubs,” said one 25-year-old festival attendee. “Are any of them having fun? If I’m going nude, I want fun.” (“Wait,” asked his friend. “What’s A.A.N.R.?”)

Wearing capes and cat ears and sometimes—to the chagrin of Como residents—real clothes, festival-goers talked about Bonnaroo and free beaches. “Mandatory nudity feels so forced,” Charlie Barcenas-Sanchez, 28, tells me as he kicks back in a hot tub. “For me, it’s just about the freedom.”

Plus, Boomers didn’t have to Instagram. Toward two A.M. one festival morning, under F.Y.N.’s U.V. body-painting tent, a woman with a blue-and-orange mountain range spread across her arms and back posed for a photo. She checked the photographer’s phone and winced.

“My thighs look huge,” she said. “Take it again.”

Joséphine de La Bruyère is a rising junior at Princeton, where she studies history and Italian