AB of the day! The bicycle!

How To Do It: Lie on floor, back pressed into the ground. Place hands behind head ( gentle hold, don't pull on your neck, no clasping of hands) with elbows  out. Lift both shoulders, upper back  off the floor. Bring your right knee in towards chest and twist torso and left elbow towards the right knee, straighten opposite leg. Switch sides, twisting torso and right elbow to bent left knee. Continue to move continuously, as if pedaling a bicycle. Do 3 sets of 20 reps 2-3 times a week.