Exercise Analysis - Cable Crossover Machine
It is difficult to separate fact from fiction in the weight room. This is not surprising because well-established beliefs that have been bandied about for years are often regarded as the gospel truth, despite the fact that they really have no basis for their existence. A classic example is the notion that resistance training against opposition transmitted through a cable/pulley system is effective for shaping, but not actually building muscle.
There are a variety of cable machines that are generally available in the typical commercial gym setting. The most popular is referred to as a cable crossover machine. This unit consists of a rectangular frame with weight stacks fixed on guide rods on each side. Pulleys are situated above and below the stacks and these provide the means through which the weight you select is applied to your working muscles. A cable passes around both high and low pulley and also around an additional one that is fixed atop the weight stack. The system is set up in this fashion so that neither end of the cable is actually attached to the stack. This allows you to perform exercises from either the top or bottom pulley without any adjustment because when you draw either of the cable’s ends toward you, the weight stack pulley will also turn. It is important to keep this in mind because the distance the weights travel will be reduced, as will the effective load opposing your movement. Consequently, the quantity of weight you have selected does not accurately reflect the amount you are working against.
The cable crossover machine allows you to perform bilateral exercises where the line of pull of the resistance is aligned with the frontal plane of your body (the plane that divides your body into a front and rear section). To do this, you must stand in the center of the unit so that the pulleys are directly to your sides. The most popular exercise done from this position is the cable crossover, which is a chest exercise that involves pulling the cable ends (handles are usually attached) from the upper pulley directly down so that they meet in front of your legs. When your arms travel inward and down in this manner, the lower segment of your chest (fibers that run diagonally down from the front of your upper arm to the top of your rib cage) is targeted. This maneuver can also be done from the bottom pulley so that your arms travel diagonally up. This would change the area of emphasis to the fibers that comprise your upper chest.
You can also work your chest on a cable crossover machine while positioned horizontally. If you lie supine on a flat bench in the center on the unit, you can perform flyes with the cables from the low pulleys just like you would with dumbbells. However, this method has a considerable advantage because when you reach end-range contraction (when you are squeezing your hands together above your chest), effective resistance is still considerable because the opposition is pulling your hands outward, not down. Flat bench cable flyes work the horizontal fibers of your chest, but emphasis can be shifted to upper or lower sections by angling the bench accordingly (at an incline or decline, respectively).
Important muscles of the shoulder can also be worked when standing in the center of a cable crossover machine. If you grab handles attached to the cables from the low pulleys and switch them to your opposite hands (the cables can either pass in front of or behind your body), you can perform lateral raises by lifting your straightened arms directly out to your sides. This exercise develops the outer head of the deltoid muscle of your shoulder, thereby making your shoulders wider. You can also bend forward so that your torso is parallel to the floor and perform the same maneuver (obviously, the cables must be passing in front of your body in this case) to shift emphasis to the oft-neglected rear deltoid section that is critical for postural integrity. Rear deltoids can also be targeted by lying supine on a bench and performing the same movement by pulling the handles down from the top pulleys.
Finally, biceps curls can be done while standing in the center of a cable crossover machine. This exercise involves grabbing the top handles and assuming a start position by raising your arms at the shoulders so that they are out to your sides and angled up. Your upper arms should remain fixed in this position throughout. The curl begins with your arms fully extended (straight at the elbow) and is completed when your hands are right next to the top of your head. Movement should occur exclusively at your elbows when you perform these curls and the angle of your upper arms should allow for a challenging load throughout the entire range of motion. If this is not the case, it might be helpful to stand atop a support structure (an aerobic step, for example) to change the line of pull of the resistance with respect to the joint at which movement is occurring.
This article was originally published in New Living Magazine, which can be accessed on-line at www.newliving.com.
