Baseball jackets and cashmere track pants will vie for the spotlight alongside more traditional evening gowns and fur coats at New York’s fashion week, as designers seize on shoppers’ growing penchant for athletic wear.

The fashion world has woken up to a trend that’s driven strong sales at Nike, Lululemon Athletica and Under Armour for the past couple of years: increasingly, men and women are trading in jeans for sweatpants, yoga gear and shorts, and unapologetically wearing them anywhere and everywhere.

“It’s huge,” said Roseanne Morrison, a fashion director at the Doneger Group, a New York-based researcher of industry trends. “It’s the new uniform.”

With activewear sales growing more than four times as fast as the $201 billion U.S. apparel industry, according to NPD Group, it’s not hard to see why designers from Cynthia Rowley to Todd Snyder planned to show so-called haute-casual or sports-deluxe clothes at fashion week, which started last Thursday and runs through Feb. 13.

In years past, high fashion has typically trickled down into everyday clothing. The activewear trend is a “truly casual,” bottom-up phenomenon, Marshal Cohen, NPD’s chief industry analyst, wrote in a blog post last week. As workout gear becomes more fashionable and is worn in more places, streetwear is looking more like athletic apparel.

Throwing on a zip-up jacket over track pants has become a lifestyle choice for men and women of all ages, shapes and economic means. Ladies who meet for lunch sport $1,000-plus Chloe leather track pants, while high school girls flock to Under Armour’s $20 running shorts. Yoga addicts and couch potatoes alike snap up Lululemon’s $82 Wunder Under pants.

The trend has opened a chasm between chains that still sell a lot of denim and those positioned in the activewear sweet spot. Under Armour’s sales rose 35 percent in its most recent quarter and Nike’s profit exceeded analysts’ estimates. Apparel chains will record a 1 percent gain in same-store sales for the last quarter, according to analysts’ estimates averaged by researcher Retail Metrics Inc.

Maria Woike, 31, an associate creative director at a New York ad agency, likes to mix things up by wearing more formal clothing with activewear from various brands.

“It fits my on-the-go lifestyle,” Woike said. “I tend to have a little bit of tomboy style. My favorite outfit is a pair of yoga pants with heels and a blazer and a retro throwback T- shirt.”

While Juicy Couture’s velour tracksuits were popular last decade, Lululemon is largely responsible for making activewear de rigeur, Morrison said. The Vancouver-based chain applied a feminine touch to a previously male-oriented category, she said.

Things went haute when French fashion house Celine elevated the look two years ago, said Sheila Aimette, vice president of North American content at WGSN, a London-based trend forecasting firm. Since then, the designer Philip Lim has made the sweatshirt redux an iconic piece, while Alexander Wang has rocked the hoodie. This spring, expect to see activewear-inspired pieces from such luxury brands as Prada and Gucci, Aimette said.

At fashion week, up-and-coming designer Anjhe Mules, 37, plans to show a $295 baseball-inspired T-shirt and futuristic compression leggings priced at $460.

“People want clothes that are more functional because they’re doing more through the day,” she said from London.