The abdominal muscles must be progressively overloaded and challenged in order to grow. When you perform abdominal exercises on a decline bench, you increase resistance. Likewise, you can use dumbbells and medicine balls while you do Russian twists, ball tosses and full sit-ups on the lowered bench. You will need a decline bench, dumbbells and medicine balls available in most gyms.
This exercise primarily activates your internal and external obliques found on the sides of your torso. Your oblique muscles create the rotating or diagonal movement during the twist. Do not perform this exercise if you have low back pain.
Sit on a decline bench with your butt on the elevated end of the bench. Secure your feet on the anchors. Leaning back halfway from the pad, clasp your hands in front of you, arms extended. Twist to your left. As you come up to the starting position, twist to your right, bringing your body to the center. Lower your body halfway back, rotating your arms toward your right side. Reverse directions as you come back up to the center. Repeat up to four sets of not more than 20 total rotations. Hold a 6-pound medicine ball to add resistance.
Ball tosses on a decline bench will stimulate your rectus abdominus, the six-pack muscle. Increase your abdominal power by gradually using heavier balls, tossing and catch the balls quickly. Avoid this exercise if you have low back pain.
Grab a 6-pound medicine ball and sit on the upper end of the bench, feet secured in the anchors. Leaning back halfway from the pad, toss the ball straight up, catching it five to six inches above your chest. Focus on your abdominals as you throw and catch the ball. Toss the ball into the air, moving your torso an inch upwards when you throw the ball. Move your torso back down an inch as you catch the ball. Repeat up to four sets of 15 to 20 throws.
The decline crunch works your rectus abdominus, especially the upper half closest to your chest. If you have problems with dizziness or light-headedness, do not attempt these crunches. Once you are done with a set, sit at the top of the bench for a moment. This allows blood flow to equalize in your body.
Sit on the higher end of the bench, one foot in the anchors, the other on top. Hold the dumbbell handle with both hands and lower your body along the pad. Extend your arms above and slightly behind your head. Focus on moving from your abdominal muscles, keeping your arms straight, bringing the dumbbell to above your chest lifting your shoulder blades off the bench. Slowly lie back down, bring the dumbbell to just beyond your head. Repeat up to four sets of 15 to 20 reps.