Muscular, classically chiseled male models are a dying breed as men are ever more chosen for thinness, even androgyny, in a fashion world playing with the notion of gender.

It only takes looking back a decade to male fashion shows -- at Versace, Givenchy, Louis Vuitton or Gucci -- to see the change on the catwalk.

Shoulders have lost their squareness, chests have sunk.

Back then, "male models were a little bit bigger... not so, so skinny," said Tricia Romani, head of the Canadian branch of the Wilhelmina international modeling agency.

Hedi Slimane, while at Saint Laurent and Dior, was among the designers who transfigured the dominant vision of the masculine look into lank, languorous and unique.

"For high fashion, that's definitely what they want. Very thin, edgy-looking guys," Romani said.

"And they're designing the clothes in that way so if you had a model that was big and muscular, that wouldn't fit."

Skinnier, the new ideal male model is also taller, hitting up to six feet two inches (1.90 meters), said Neil Mautone, founder and owner of the agency Red Model Management.

Along with the fading ideal of muscle is the classically beautiful face, formerly in demand for men as well as women.

Today, according to Romani, "a male model can be sort of interesting looking, or edgy or different" and be hired even if he does not fall into "a category of plastic, beautiful models."

With the growing power of male fashion, seen in the 2015 launch of the first men's shows in New York Fashion Week, demand for male models has exploded.

Between 10 percent to 15 percent of male models find enough work to be employed full-time, combining runway shows, advertising, catalogs and magazines, Romani said.

The top-end models can earn more than $1 million a year, people in the industry say, though the best-paid female models can make about 10 times more.

- Man, woman, who cares? -
Responding to the growing market, model agencies and designers are trashing stereotypes and broadening their palettes, an approach that is also boosting ethnic diversity, Romani noted.

The new ideal look, the evolution of men's fashion and the current focus on gender have blurred the lines between men and women.

That was more evident than ever on the New York catwalks last week.

Several shows were decidedly "gender fluid," parading out clothes that could be worn by either sex.

The streetwise New York brand Hood By Air, a pioneer of the trend, was joined by Dutch studio Maison the Faux and Baja East, a New York-based company known for relaxed luxury apparel.

For Maison the Faux, undoubtedly the most radical of them all, the men walked the runway wearing bras and girdles.

"Society always puts people in boxes and I think that doesn't make the world a better place," said Tessa de Boer, one half of the design team at Maison the Faux.

The Wilhelmina agency has among its models a 26-year-old person who refuses to identify with a gender and goes simply by the name Lex.

The model notably has worked for N-p-Elliott, where Scottish designer Nicholas Elliott conjures up avant-garde, asexual clothes.

"Being so androgynous, to me, is a blessing," Lex told AFP in an emailed response to questions. "It increases my ability to participate in endless projects without limitation to my gender."

"If men and women are equal, then what does all that matter?"