Crunches are a common abdominal exercise used to tone the muscles around your mid-section. Well-developed abs that are not obscured by fat have a washboard appearance, with the individual heads of the muscle sometimes collectively called a six-pack. A cross crunch is a specific type of crunch, and there is also an ab workout device with the same name.
Exercising the Abdominal Muscles
While there are many techniques and devices that are designed to exercise, strengthen and develop the abdominal muscles, not all motions will significantly involve this specific muscle group. Generally, exercises that are conducted in the supine position, that is laying on your spine, will involve more activity in the upper abdominals that vertical exercises that are done standing or hanging.
Crunches
An abdominal crunch is like a mini-sit up -- it's done from the supine position and involves only a partial motion of the chest towards the knees. According to Dr. Kravitz, crunches are effective at developing the abs because only the first 35 to 40 percent of a sit-up involves significant contraction of the abdominal muscles. The rest is performed by the hips and back. Crunches then simply limit the extent of the motion so effort can be concentrated more specifically on the abs.
Cross Crunches
A cross crunch, or cross-body crunch, is nothing more than doing a crunch with just one side of the body. In a cross crunch, the left shoulder is brought towards the right knee, or vice versa, and the process repeats in alternating fashion. You can also move the knee towards the shoulder. Like regular crunches, cross crunches primarily work the upper abdominals, the top four heads of the "six-pack." The lateral motion also partially works the lateral obliques, although Dr. Kravitz of the University of New Mexico posits that such lateral motion actually works deeper muscles closer to the spine, but may help improve overall range of motion.
Cross Crunch Device
The trademarked Cross Crunch device is an abdominal exerciser that is supposed to increase the effectiveness of crunches by introducing additional, variable resistance. Doing a cross crunch from a seated position with this device is a way to introduce resistance training to the ab workout -- although several studies on other ab devices suggest such equipment generally does not improve the effectiveness of unaided techniques. While resistance training could potentially help develop the size of the abdominal muscles, it does little to burn the fat that may be obscuring them.
References
- Univ. New Mexico; Dr. L. Kravitz; SuperAbs Resource Manual
- Six Pack Now; Oblique Exercises
- Bodybuilding; Cross-Body Crunch
- Journal of Strength and Conditioning Research; Electromyographic Analysis of Abdominal Muscle Activity Using Portable Abdominal Exercise Devices and a Traditional Crunch; Aug. 2003
- Cross Crunch; About the Cross Crunch
Member Comments