Ruby Rose does 300 sit-ups a day

Los Angeles: Actress Ruby Rose has admitted she keeps her abs defined by doing 300 sit-ups a day. The "Orange is the New Black" star keeps her washboard abs intact by following the gruelling regime every evening, reports  Taking to her Instagram account on Thursday night, the 30-year-old actress uploaded a photograph showing off her abs while wearing a skimpy crop-top.  "Life is better after 300 sit-ups," she captioned the image.  Rose recently shared she wishes she had a perky backside. She was bombarded with messages from fans claiming she had "no a**" after she uploaded a photograph of herself in a pair of shorts earlier this year. But rather than taking the insults to heart, Rose hit back at the haters by mocking herself and agreeing with them.