The most popular chest exercise is without a doubt the bench press. "How much do you bench?" That is the number one question a bodybuilder gets asked, be it at the gym or in any other public setting. And while the bench press is an excellent chest mass builder, there is another exercise that is even better at pin-pointing the pectoralis major, which is the major muscle of the chest. That exercise is the chest fly.

But, there is more to this.

The type of exercise machinery you use while doing chest flys can make quite a bit of a difference in terms of effectiveness. This has to do with something called constant tension. When using dumbbells to do chest flys, you cannot keep constant tension on the chest at the top of the motion, thus allowing your pectoralis major muscles to rest. However, when you use a cable pulley, you are able to maintain constant tension throughout.

You can even increase the range of motion of the chest fly when using cables. Your pectoralis major muscles allow you to cross your arms across your chest, past the mid-line. When doing the chest fly with dumbbells, you must stop the motion when your arms are across the mid-line of your chest. But, with cables, since there is constant tension throughout, you can continue the motion past the mid-line and further contract your pectoralis major muscles.

It is best to do cable chest flys while lying down on a bench to maximize strict motion and ensure that your chest is being worked in near isolation.

The pectoralis has three divisions: upper, middle and lower. These are anatomically referred to as the clavicular, sternocostal and abdominal heads, respectively. And you need to use an incline, flat or decline bench to work those parts of the pectoralis major, respectively.

Execution: position a bench right in the center of two cable pulleys. Adjust the angle on the bench depending on which part of the pectoralis major you want to emphasize. Grasp the cable pulley hand grips using a neutral grip. Position your arms over your chest with your elbows pointing out. Don't keep your arms locked, but rather bend them slightly. This is the starting position for the chest fly. At this point, move your arms away from the center of your chest in an arc-like motion. Once your arms are parallel to the ground, stop the downward motion and raise your arms back up, again in an arc-like motion. However, don't stop the upward motion once you reach the original starting point. Keep the motion going until you have criss-crossed your hands over your chest. Squeeze your chest muscles and then repeat the movement. Perform 10 to 12 reps per set and complete a total of three sets of this exercise during your chest workouts.

Variations: you can do the cable chest fly unilaterally, meaning one arm at a time, to better focus on each side of your chest. When doing the exercise in this manner you can do the 10 to 12 reps consecutively using only a single arm, before switching over to the other arm. Or, you can do one rep with the right side, followed by a rep with the left side.In this case, you would keep alternating between the two sides until you reach the aforementioned target rep count.