Heres a Workout To Make these 3 Major Muscles In the Abs Pop EXERCISES FOR SERRATUS, RECTUS ABDOMINUS AND EXTRNAL OBLIQUES: Decline Crunch 4X20 Cable Crunch 4X20 Elbow To Knee 4X20 Knee Raise On Pull Up Bar 4X10 Reverse Sit Up 4X15 Dumbbell Side Bends 2X50 Do this 5 days a week for 30 days and see them pop.