Arena, an Italian waterwear brand, has created the unthinkable: a high-tech swimsuit that outraced Michael Phelps and it doesn't even have some kind of motor. At the world championships in Rome this summer, German Paul Biedermann, wearing Arena's Powerskin X-Glide racing suit, handed Phelps his first major individual international defeat in four years, in the 200-m freestyle. The light, polymeric surface of Arena's full-body supersuit traps air to boost a swimmer's buoyancy, reducing drag in the water. Biedermann admitted the suit gave him an advantage, and Phelps' coach threatened to pull the phenom from future meets if it wasn't banned. Starting Jan. 1, the X-Glide and other swimsuits made from plastic derivatives are no longer permitted in international competition.