Step 1: Lie flat on the floor with your lower back pressed to the ground (or a mat if you need a little cushion like I do) and contract your core muscles
Step 2: With your hands gently holding the back of your head, lift your head up so your shoulders slightly come off the floor.
Step 3: Lift your knees to about a 45-degree angle.
Step 4. Slowly go through the bicycle motion, touching opposite elbow to knee while pulling your leg towards your head
Step 5: Breath as you alternately touch your elbows to the opposite knees and twist back and forth.
Image from: womenshealthmag.com
Find an exercise...