Holding Your Body Up & Lifting Your Legs Up and Down During Stomach Crunches

You may do many variations of stomach crunches. The slight changes made to each crunch alter the results of the crunch. You can manipulate the exercise to concentrate more on certain areas such as your "six pack," your lower abdominal area, the upper abdominal area or the sides of your stomach. Holding your upper body up during a crunch creates a greater challenge for the leg-lifting reverse crunch.

  1. Isometric

    • When you hold your upper body up during an abdominal exercise, you look as if you are frozen in place at the top of the crunch. For example, lie face up on the floor with your knees bent, feet on the floor and your hands behind your head. Raise your head, arms and shoulder blades off the floor and then maintain that position. This creates an isometric contraction in your rectus abdominis, the outermost abdominal muscle. You hold this contraction steady throughout the leg-lifting exercise to create greater intensity for the crunch. This position also keeps your back flat against the floor.

    Leg-Lifting

    • The leg-lifting part of the abdominal crunch is known as a reverse crunch. Instead of creating the abdominal contraction from the top down, you contract the lower portion of your abdominals first. In your face-up lying position, with your knees bent, raise your feet off the floor. As you exhale, bring your knees toward your chest and then raise your hips slightly to contract the core even more. As you inhale, return your feet to the floor for a quick touch and then repeat the reverse crunch.

    Muscles

    • Your rectus abdominis, which is a thick band of muscle fibers that runs vertically down the center of your abdominal area, and your obliques, which are situated along the sides of your abdomen, are responsible for the movements of the upper-body lifted reverse crunch. When you shorten the distance between your ribs and your pelvis, the rectus abdominis contracts. When you shorten the distance between the sides of your ribs and your hip bones, the obliques contract. Both these actions occur during this exercise. You also tighten the transversus abdominis as you flatten your navel toward your spine to maintain the isometric lift.

    Workout Guidelines

    • Your abdominal muscles are not quick to fatigue, as they support your daily movements and have a large amount of endurance. As a result, you can train them every day, according to Dr. Len Kravitz, Associate Exercise Science Professor at the University of New Mexico. The upper-body lifted reverse crunch can be used as part of your core-training routine when you complete one to three sets of eight to 20 repetitions. If you experience any discomfort, avoid the exercise and speak with your doctor.