When she began playing tennis several years ago, Yesim Philip, a former professional basketball player in her native Turkey, felt frustrated by the traditional tennis whites sold in stores, calling the offerings “too technical” and “unflattering.” So the New York-based designer launched her own athletic brand, L’Etoile Sport, in 2012, with a simple goal: to design more stylish women’s tennis apparel. “Back then, nobody was doing ath-leisure or luxury tenniswear. People were laughing at me, saying no one was going to pay $165 for a tennis skirt,” Philip said. Shortly thereafter, Philip expanded into golfwear and for fall, her L’Etoile Sport label continues to grow with the addition of a full-fledged activewear collection. “The whole idea is ‘play all day.’ You can work out in it and then go to lunch,” Philip said. Her fabrics are technical — with cooling effects, built-in SPF and reflective properties — as well as sophisticated, with perforated mesh accents and a subdued color palette. Launching in August on Net-a-porter.com, letoilesport.com, in resorts and private country clubs, the collection will range in price from $115 to $365.