Hip twists are a great toning exercise to define your waist and strengthen your core. They're also a nice change of pace from those twisting crunches.
They're demonstrated here by YouTube fitness sensation Cassey Ho, who uses them on her "Pop Pilates Total Body Workout" DVD and Blogilates channel. Add them to your next ab workout.
What it does
This exercise strengthens the oblique muscles that run along the sides and back of your abdomen, helping to create a more defined waist and supported back. It also gives you a little bit of a shoulder workout at the same time.
What to do
From a reclining position on the mat, rise and prop yourself on your elbows, with hands clasped and legs extended straight out into a plank position. Keep your back, legs and neck in a straight line, and your tailbone tucked under to protect your back.
Next, twist your body and touch your right hip to the floor. Lift to come back to center, keeping your body in a straight line. Then twist to the other side and tap your left hip to the floor before returning to center. If this is too difficult, you can come down to your knees to twist to each side and tap.
Do 20 taps on each side.