The pec deck is a kind of weight machine that is meant to exercise your pectoral muscles. Seated machines, pec decks also come with an adjustable quantity of weight attached to them. The portion of the pec deck where you rest your arms usually can be adjusted either down or up so that you can increase the potential of exercising your pectoral muscles when bringing your arms together. Mechanically, a pec deck is made up of a frame, a pulley attached to two bars that are suspended and an adjustable seat. The maximum weight that you can attach to the pulley of this machine totals around 200 pounds.

Using a pec deck, you will work toward ripping your chest muscles in general. While this machine targets muscles like your pectorals for the most part, it also exercises others. In a secondary nature, the pec deck will work out the muscles in your upper shoulders and upper back. An example of these muscles that the machine works in a secondary fashion is your trapezoids, your rhomboids and your latissimus dorsi. When you move your arms on this machine, your muscles contract, which gives them room to expand in size. Your muscles are given time to isolate when you relax them after the conclusion of a repetition.

Critics say that the architecture of the pec deck lends itself to injuring users because of the unconventional placement of their shoulders on the machine. When you sit on this machine, your shoulders may feel as though they are being exerted because of your position sitting on a straight seat back together with the motion of your arms as you complete an exercise. Be especially on the lookout for any signs of pain in this position, and if you feel even the beginnings of such pain, stop the pec deck's use immediately.

Your ligaments may be stretched too far when using the pec deck. When this occurs, you will feel strong pain in your shoulder area. If this occurs, stop immediately, and make sure you're using proper form. Proper form consists of squeezing the bars toward your body. The weight will then be pulled up by the pulley, during which time you should exhale. When you inhale, you then release the weights to their initial position by moving your arms away from each other.

A form of exercise you can do on a pec deck is the one-arm rows. You get to really work out your arms with this exercise, which involves pulling one of your arms at a time toward your back, where you'll hold it like that for a couple of seconds. Another kind of exercise is the common reverse pec deck fly. This involves you pulling your arms farther away from the front to the back as far as they will go, while bending the elbows.