Stunning in a glittering red Isaac Mizrahi gown, Good Morning America co-anchor Robin Roberts strutted her stuff for the designer's studio fashion show. As part of GMA's "I Dare You" segments, Roberts's colleagues challenged her to walk the catwalk. "When I first heard about their dare I was like 'No way!' because I have felt anything but beautiful going through this battle with cancer," Roberts tells PEOPLE. "And then I thought, 'Heck yeah!' What better way to get my mojo back?"