Today's Bikini Body Countdown  workout starts with a quick cardio intervals to burn some calories and belly fat and ends with a focus shaping some sexy shoulders. And it only takes 30 minutes! Start with 20 minutes on the treadmill, playing with both speed and incline (or try this elliptical workout ). Then end your sweat session with 10 minutes of arm work with celeb trainer Anna Kaiser.
Treadmill Workout: 20 Minutes