The abdominal muscles can be a tricky group to train -- 1,000 crunches and your abs are still hiding under that lovely little layer of flab. While crunches and situps are low-impact, they do little to strengthen and tone your abs as a whole. There are several low-impact exercises that activate the bulk of your abdomen and core to help strengthen and tone your entire mid-section.
Stability Ball Hyper-Extension Situp
This stability ball hyper-extension situp exercise targets your rectus abdominis muscles and, to a lesser extent, your obliques. The movement of this exercise is similar to the basic situp, however it requires you to move through a much greater range of motion with your abs starting from a lengthened position rather than at rest. Sit on a stability ball and slowly walk your feet away from the ball allowing the ball to roll up your body until your back rests over the top. Extend your arms overhead until your fingers are touching or nearly touching the floor behind you. With your knees bent and feet firmly on the floor, contract your abdominal muscles and exhale as you slowly lift your torso until you're in the sitting position. Slowly lower back to the starting position. The slower you move during this exercise, the more you're going to feel your abs working. For a greater challenge, hold a 2- to 5-pound plate weight in your hands. Avoid this exercise if you suffer from low-back problems.
The plank exercise is a surefire way to strengthen and tone your abdomen with minimal impact. It targets the bulk of the abdomen including the rectus abdominis, transverse abdominis and obliques as well as a few back and arm muscles. Begin in a pushup position then lower down onto your elbows. Straighten your back, contract your abs and glutes and stabilize your hips. Your body should form a straight line from your head to your heels. Hold this position for 30 to 60 seconds while continuing to breathe regularly.
This low-impact abdominal exercise strengthens and tones the internal and external oblique muscles that run along the sides of your abdomen. Lie on your right side with your elbow supporting your upper body. Extend your legs and stack your hips, knees and feet. Contract your obliques to lift your hips off the floor until your body forms a straight line. Lower back to the floor. Complete the desired number of reps then repeat the bridge with your left side.
The alternating quadruped is a low-impact exercise that targets the back extensors, which are often neglected during abdominal strengthening exercises. When working on the abs, it is crucial to work these muscles as well to keep your entire balanced and strong. Begin on all fours with your knees below your hips and your hands under your shoulders. Take a deep breath in and as you exhale, lift your right arm and left leg simultaneously. Extend them until they are horizontal and your body forms a straight line from the tips of your fingers to the tips of your toes. Keep your back straight and pelvis stable during the exercise. Pause at the top of the movement, slowly return to the starting position then repeat the exercise with your other side.
Jen Weir writes for several websites, specializing in the health and fitness field. She holds a Bachelor of Science in exercise science from Montana State University, is an NSCA-certified strength and conditioning specialist and maintains a personal trainer certification from the American College of Sports Medicine.