Popsugar Health & Fitness Workouts Exercises For Abs Your Flat Abs Are on Their Way If You Do These 50+ Core-Carving Moves 13 August 2018 by Jenny Sugar View On One Page Photo 50 of 55 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 50 Knee Driver Begin in an elbow plank position with the abs engaged. Draw the left knee into the chest. Then step the foot back to the elbow plank position. Now draw the right knee into the chest and then step it back to the elbow plank position. This counts as one rep. Previous Next Start Slideshow WorkoutsAb Exercises