Doing exercises that work the oblique muscles that line the sides of your waist can help you strengthen and engage your abs for a tighter, more pulled-in look. This twisted plank exercise is a favorite of Nicole Nichols, a certified personal trainer and star of the Total Body Sculpting DVD.
How to do it: Come to a side plank position with the feet and legs stacked, hand directly under your shoulder and your top arm extended [as shown in photo A]. As you exhale, reach your hips higher from the floor while threading your top hand under the body, reaching behind you [as shown in photo B]. Return to face forward to complete one rep. Work your way up to three sets of 15 reps on each side.