Forget Netflix amp Chill Let s Get Rock Hard Abs this Weekend amp Build Decline bench blasts your core muscles 1 Decline Bench Russian Twists- activates your internal and external obliques found on the sides of your torso 2 Decline Bench Ball Tosses- Ball tosses on a decline bench will stimulate your rectus abdominis the six-pack muscle 3 Decline Bench Ab Sit Up- improve core strength prevent injury and help to stabilize your body Sit up to shred down