Why has Nike crossed paths with Riccardo Tisci (see photo), Adidas with Kanye West, Puma with Rihanna and why has Beyoncé designed her own activewear line? The answer is simple: the numbers say that Athleisure i.e. casual attire meant to be worn both for exercising and for pretty much anything else, is the new buzzword to bring profits. According to Morgan Stanley, sportswear and sports shoes have grown by 42% in the last 7 years (239 billion euros) and are expected to grow another 30% by 2020. In the United States alone, the activewear line has generated 44 billion US dollars (+16% in 2015), according to figures released by the NPD Group.