This month's regimen (look for part 2 next month and part 3 in April) targets your core (torso and hips), to give you flatter, firmer abs and a stronger back. "Your core muscles work to maintain your posture and alignment as the rest of your body moves," explains Leigh Crews, star of Core on the Floor DVD, who designed this workout exclusively for Shape readers.
WHAT TO DO
Do 1 set of each move in the order listed below 2-3 times a week either as a stand-alone workout or as part of your regular workout. Warm up standing, rotating your torso side to side 10-15 times, then do about 10-15 pelvic tilts. Finish by stretching your torso in the traditional yoga child's pose, kneeling with hips on buttocks, draping torso over thighs, arms outstretched on floor for 4-5 breaths.
Beginner's Advice Do this entire workout only once a week with the minimum reps recommended in each caption.
More Advanced? Repeat all 4 moves a second time.