MIAMI BEACH, FL - DECEMBER 10:  Amy Steiner (C) leads a yoga class while dressed in Lululemon Athletica yoga clothes at the Green Monkey yoga studio on December 10, 2013 in Miami Beach, Florida. Lululemon Athletica, Inc. announced today that it is naming Laurent Potdevin as their new chief executive and said founder Chip Wilson will step down as chairman.  (Photo by Joe Raedle/Getty Images)