 Rihanna said she stepped up her workout routine. She was getting 10 minutes of cardio. And now she has cardio, whether it's on an elliptical or a bike or running or just, she says, jumping jacks help. But she now does 30 minutes four times a week. And she says that will work because what you have to do is then squeeze on three half-hour workouts and stay to 30 minutes. Don't go any longer.