Motion Commotion

OLIVIA NEWTON-JOHN'S REFRAIN of "Let's get physical," along with the ubiquity of Lycra, started it in the 1980s. Aerobics helped push it into the '90s, and yoga certainly added an aura to the category in the new millennium. Chanel, Prada, Dior and Hugo Boss all capitalized on it a few seasons ago. Activewear has come a long way from the gym and, thanks to relaxed dress codes inaugurated by casual Fridays, it has become a uniform for more and more Americans. But it's not about cotton T shirts and sweats anymore. Today activewear can mean everything from a high performance, temperature-regulating jacket designed by a fashion star to an urban-chic hoodie created by a Hollywood hottie.

Like Scarlett Johansson. Reebok, which recently merged with Adidas, next year will launch a new line of urban activewear designed by the actress. Johansson, known more for her curves than her curveball, doesn't convey the tomboy image that a company like Reebok may want, and that's the point. Her line, Scarlett ♥ Rbk, will feature such activewear staples as hooded jackets and baseball T shirts, but they will be made from the latest fabrics and infused with Johansson's love of Old World glamour. "I'm sick of spending more time shopping for a T shirt that fits than for an evening gown," she said recently in New York City. "I'm designing this for contemporary, urban young women. I'm inspired by the '80s, when women were exercising with false eyelashes and things like that."

Johansson may be onto something. To inject some vitality into its activewear offerings, Adidas last year collaborated with designer Stella McCartney, and her debut line of functional and fashionable running and tennis wear sold so well that the German apparel maker committed to working with her until 2010. Such partnerships between the worlds of sports, fashion and Hollywood are quickly making high-performance sportswear, which combines the best of technology with the latest in design trends, the newest battleground in the highly competitive athletic-apparel market. For companies like Adidas and Reebok, developing these lines not only is a smart way to address the increasing demands of the consumer but also makes economic sense as a way to compete in the overcrowded clothing market.

"What we're seeing is a movement to more technical fabrics and more innovative fabrics because the apparel market is such a commodity business," says Gregg Hartley, V.P. of the Sporting Goods Manufacturing Association (SGMA). "If manufacturers want to maintain margins and brand identity, they have to have something innovative, something new to build their brand."

Adidas, Nike, Champion, Russell and Reebok have long bridged the gap between competitive sports and casual activewear. But increasingly, consumers want both function and fashion from their sportswear. Clothes need to do something—stretch, fight odor, wick moisture, regulate temperature—and look good as well. "We always saw athletic wear and style as mutually exclusive," says Julee Bean of Adidas. "And they don't need to be. You can wear our product in the gym but also wear it to get a latte and still look hot."