By Stephen E. Alway, Ph.D., FACSM
One of the best ways to get your abs in shape without killing the intensity from your other body parts is to throw in some extra sets of ab work (like supersets) between your regular training sets. The bicycle crunch is an excellent exercise that will hammer your entire abdominal wall, yet it requires no equipment and it can be readily done between your sets of weight work in the gym, at home or even in your office at work.
This exercise is a combination of a modified crunch, leg raises and twists. It will activate your anterior and lateral abdominal wall (rectus abdominis, internal oblique and external oblique muscles) and the leg raise part activates the lower part of the rectus abdominis and the iliopsoas.
The centrally positioned rectus abdominis is anchored to the pubic bones of the pelvis and superiorly, to the xiphoid process at the base of the sternum. The upper portion of the rectus abdominis is wider and stronger than the lower sections. Usually there are three rows or blocks of tissue at the level of the xiphoid process below the sternum, the umbilicus (“belly button”) and about halfway between these two structures. If the right side of the rectus abdominis contracts, the torso will bend to the right. However, if both right and left halves contract, the head and chest will move closer to the legs.
The external oblique runs from the fifth through the twelfth ribs, down to the pubic and the iliac bones of the pelvis. When both left and rights sides of the external oblique muscles work together, they flex the trunk so the head moves towards the feet. If only one side contracts, the trunk flexes towards the opposite side.
The internal oblique muscle lies deep to the external oblique muscle. It begins along the lower back, and the iliac bone of the hips, and extends upwards to the lowest three or four ribs. If the right side of the internal oblique contracts, the body will twist towards the right. Similar to the external oblique muscle, if both left and right portions of the internal oblique contract together the trunk flexes forward.
The iliacus and psoas major muscles combine to make the iliopsoas muscle. The psoas major attaches to the sides of the lumbar vertebrae and the intervertebral discs of the lower back, and it extends downward to attach to the femur bone of the thigh. The iliacus lies along the inside of the iliac bone of the hip and its fibers run downward and medially to attach to the tendon of the psoas muscle. The iliopsoas bends the lumbar region anteriorly (forward flexion) and it is strongly activated during the leg raise part of bicycle crunches.
THE EXERCISE: BICYCLE CRUNCHES
1. Lie flat on the floor with your knees bent and your feet on the floor. Place your hands behind your head.
2. Lift your scapula (shoulder blades) off the floor and keep them here throughout the exercise. Be careful that you do not pull on your neck with your hands.
3. Extend your left leg. Your thigh should be at a 45-degree angle to the floor but your leg (knee to ankle) can be roughly parallel to the floor. At the same time, your right knee and hip should flex and come up towards your chest.
4. Twist your upper body so that your left elbow comes towards your right knee; at the same time bring your right knee up towards the left elbow. Be sure that your torso is moving and not just your elbows.
5. Move your torso back to the midline position, then smoothly transition to the other side.
6. Twist your body and lift your upper back from the floor, so that the right elbow moves towards the left knee and at the same time, lift the left leg towards the right elbow. The complete cycle from the left to the right knee is one repetition. This is somewhat akin to a “peddling” motion (extending and flexing the knees), and hence the name of the exercise.
It is not necessary to touch your elbows to your knees, especially if this would mean putting stress on your neck. It is not important to go super quickly. It is better to keep a good, moderate pace with constant tension on your abdominals.
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