When you perform isolation exercises for your lower abdominals with a stability ball, you’re not only using the lower abs for the primary movement of the exercise, you are also using them to maintain stability and balance. An unstable surface boosts the pressure on your abs to achieve even greater strength and endurance. While pulling your chest to your hips will work your upper abs, reversing the movement by drawing your knees to your chest will condition your lower abs. Perform five to 10 minutes of light cardio before plunging into a lower abs routine.
A reverse crunch on a stability ball is an advanced exercise that targets your lower abdominals. Begin by placing the ball in front of a heavy chair or bench that has the same height level as the ball and won't move around. You should be able to lie on the ball and reach overhead to grab the bench for support. Drape your torso over the ball so the small of your back rests comfortably on the middle of the ball. Extend your arms overhead and grab the bench behind you with your palms up. Lift your legs so your thighs are perpendicular to the floor and your knees are bent at a 90-degree angle. Exhale and draw your knees in toward your chest, lifting your hips off the ball. Inhale and slowly return to starting position. As soon as your tailbone touches the ball, immediately perform the next crunch. Perform three sets of 12 to 15 reps. Try not to rock or use momentum to finish the exercise.
Because you’re pulling your knees toward your chest, the stability ball knee tuck will blast your lower abs. Start on all fours with your stomach draped over the ball and your hands and feet flat on the floor. While keeping your legs together, extend them behind you. Slowly walk your hands forward, rolling the ball beneath you, until the ball rests below your thighs or knees. Establish a plank position with your arms extended and your torso and legs forming a straight line. Exhale and bend your knees, pulling them toward your chest to roll the ball forward. Hold the peak position for a second, contracting your lower abs. Inhale and straighten your legs. Roll the ball back to the starting position. Perform two to three sets of 12 to 15 reps. To boost the difficulty of the exercise, add a push-up before you execute the knee tuck.
By doing V-ups with an exercise ball, you can give both your lower and upper abs a rigorous workout. Lie on the floor and hold the ball between your knees with your legs extended. Cross your arms over your chest. Exhale and simultaneously raise your upper and lower body. At the top of the movement, your upper body should form a 30-degree angle to the floor. Draw your legs to your chest and hold the peak position for a second. Inhale and slowly lower your upper and lower body until just before they touch the floor. Keep your abs squeezed and immediately perform the next rep. Use controlled and fluid motion to perform 15 reps.
Tips and Considerations
If you use rocking motion or your arms to help pull your knees toward your chest, it defeats the purpose of a lower abdominal exercise. The point of isolating your lower abs is to use only that muscle group in the primary movement of the exercise. Keep your head, neck, arms and hands relaxed and focus on contracting your lower abs to do the work. If your form starts to slip, take a rest interval or stop the exercise. Poor technique can result in excessive pressure on your lower back. Maintain a fist-sized distance between the jaw and breastbone to prevent neck strain.