Ruby Rose does 300 sit-ups a day.
The 'Orange is the New Black' star keeps her washboard abs intact by following the gruelling regime every evening.
Taking to her Instagram account on Thursday night (16.06.16), the 30-year-old actress uploaded a photograph of her parading her defined stomach in a skimpy crop-top.
She accompanied the shot with her secret to her flat stomach, writing: "Life is better after 300 sit-ups."
However, although she's proud of her impressive tum, Ruby recently admitted she wishes she had a perky backside.
The brunette beauty 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 take the insults to heart, Ruby hit back at the haters by mocking herself and agreeing with them.
Taking to her Twitter account at the time, Ruby wrote: "If you can't make fun of yourself (and watch other people take credit for it) then what's the point of living? To people saying I have no a**.. You're right.. You think I don't know? I basically sit on my lower back. I've never had an a** or boobs.. So shoot me.. Preferably in the a** that I don't have. (sic)"