Get into an extended arm plank, propped up on your hands with hands directly beneath your shoulders, feet hip-width apart. Press down on the gliders and slowly pull the knees in so they come about 4 inches in front of your hips. Then, push back to starting plank position, keeping the core tight the entire time, drawing the navel in. Do for 30-45 seconds, or 10-15 reps. You should be moving very slowly to get the most out of each move, Stokes says.
