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 29 of 55 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 29 Straight-Leg Sit-Up Begin on your back with your legs straight and arms raised toward the ceiling. Roll up to sitting, focusing on the abs rounding the back. Roll back down to the mat slowly, one vertebra at a time. This completes one rep. Previous Next Start Slideshow WorkoutsAb Exercises