Sexy isn’t what it used to be.

Charlotte Herrold explores fashion’s provocative new attitude.

Again with the sweatpants?” This line, from Seinfeld, flashed through my mind as I pulled on the heather-grey cotton-jersey dress I’d been wearing at least once a week since nabbing it in Amsterdam last spring. “You know the message you’re sending to the world?” Jerry asks George. “You’re telling the world ‘I give up.’”

As I accessorized my sweats-inspired dress with a well-worn moto jacket and black Nike runners (yes, the same ones I wear to the gym), I thought, “If this is giving up, why do I feel so good?” The answer became clear as soon as I hit the street: I was not only completely comfortable but also totally on trend.

If the fall/winter 2014 season had a singular message, it was “Flats are in. And skin? Keep it covered.” With the exception of the miniskirt— often tempered by long sleeves and high necklines—the catwalk look was cozy, covered up and conducive to a life on the go lived in increasingly unpredictable climates. There were blanket coats at Burberry and head-to-toe knits at Marc Jacobs and The Row. Even Chanel’s Karl Lagerfeld, who, in 2011, was quoted echoing Jerry Seinfeld’s dictum—“Sweatpants are a sign of defeat: You lost control of your life, so you bought some sweatpants.” —showed ripped salmon sweats paired with knee-high flat running boots.

Once upon a time, in the early 2000s, sex appeal was all about stilettos, plunging necklines and body-con silhouettes—think JLo’s infamous deep-V Versace, Britney Spears’ low-rise denim and Posh Spice’s many bandage dresses. A decade later, the mood has shifted: Now it’s sneakers and slouchy silhouettes that feel fresh. Victoria’s Secret’s 2014 “What Is Sexy” list celebrated babes with laid-back, demure style, not bombshells: Alexa Chung, pictured in jeans, a knit sweater and a long jacket, took home “Sexiest Street Style” honours. Today, it seems, sexiness is about women breaking free of tired hyperbolic ideals of femininity and redefining how they want to feel in their clothes.

What has changed? Sheila Aimette, vicepresident at global trend forecaster WGSN, suggests that the casual-style trend is rooted in the cultural mainstream’s embrace of all things active. “The shift encompasses everything from organic food to specialized exercise classes,” she explains,

noting that gym clothes are now stylish enough to move from desk to dance class. “Fashionable functionality trumps super-sexy right now.”

Functionality certainly rules in footwear: Flats and designer sneakers now outpace vertiginous heels as fashion must-haves. Karen Blanchard, a New York-based street-style photographer and the blogger behind Where Did U Get That, credits Céline’s “furkenstocks”—those spring/summer 2013 fur-lined orthopaedic-looking sandals—as the genesis of flat footwear’s ascent to high fashion. “When those Céline sandals came down the runway, everyone’s eyebrows were raised,” remembers Blanchard. “But quickly there was this consensus of ‘It looks weird, but it’s cool.’” It was also provocative: Those shoes aren’t about increasing your desirability; they’re about shrugging at the very notion of desirability.

Comfort is the foundation of the trend’s appeal. “I love that wearing flats is a trend right now, but it’s something I’d do anyway,” says Blanchard, who, when we spoke, was preparing to snap the scene at New York Fashion Week. “I’m on the street for 12 hours at a time, lugging around a heavy camera and trying to elbow other photographers out of the way!”

Thomas Tait, the London-based, Montrealborn designer, has won high praise—including this year’s LVMH Young Fashion Designer Prize—for his clean, minimal designs, where sexy style takes a back seat to sporty chic. “I don’t focus on trying to exaggerate the things that women traditionally think of as sexy,” he says. “I’m not about the ass. Women want something they feel good in. It’s only when they feel comfortable that they have the freedom to express sexiness and confidence.”

Today, sexiness is about women redefining how they want to feel in their clothes.

So, does the sartorial reimagining of sexuality spell the death of the towering stiletto? Can we say bye-bye to body-con? As Blanchard points out, that’s unlikely. “There will always be women who feel sexiest in stilettos,” she says. The most important takeaway of the trend, then, is that it offers a nuanced interpretation of femininity: We’re no longer restricted to a set of definitive one-size-fits-all traits, whether they’re casual cool or overtly sexy.

“Our ideas are constantly evolving because women are always changing,” explains Tait. “That’s what’s so fascinating about designing womenswear.” Sexiness, then, isn’t so much about what we wear but the attitude with which we wear it. What could be cooler than that? ■