Cable Lying Fly

So-called fly exercises are popular exercises for isolating the chest muscles as much as possible. The main function during this exercise is pulling the upper arms forward using the pectoralis major. Because the arms maintain the same curve throughout the movement, the triceps are required much less than during the bench press. The biceps must still be kept under tension continuously to hold the arms in a slightly bent position.

Flyes can be performed with dumbbells, machines, or cables.

An advantage of the cable and machine variants is the constant tension that is also maintained at the end of the exercise. In the lying dumbbell variant, you lose this tension at the end of the movement.

Using cables also allows you to make the exercise somewhat larger. The hands can also cross in front of the body. This variant is called the cable crossover flyes.

Besides the standing variant, the exercise can also be performed seated or lying on a bench. The seated and lying variants have the advantage that you need to work less from your core to maintain your position.

Cable Lying Fly execution

1
Bring your hands together as if embracing a tree. Optionally cross your hands over each other to perform a crossover variant. Keep your arms slightly bent and maintain this curve throughout the entire movement.
2
Return your hands to the starting position in a controlled manner.

Cable Lying Fly

Active muscles:

Pectoralis major (chest muscle)
Anterior deltoid (front fibers of the shoulder muscle)
Serratus anterior
Coracobrachialis

Stabilizing muscles:

Rotator cuff (stabilizing shoulder muscles: supraspinatus, subscapularis, teres major, teres minor)
Biceps brachii
Serratus
Trapezius
Triceps brachii
Latissimus dorsi
Core muscles

Cable Lying Fly setup

Attach the single handles to both sides of the cables.
Set the pulleys to their lowest position.
Place a bench in the middle of the cable rack. When you lie down, your shoulders should be level with, or slightly lower than, the pulleys.
Hold both handles and stand with both legs over the bench. Then sit down and lie back.
Check (again) that you are lying properly in the middle, straight, and at the correct height relative to the pulleys.
Your hands are already being pulled to either side by the cables, so they are already in the starting position. Make sure your elbows do not come higher than your shoulders (toward the head).

Cable Lying Fly technique

One of the most common mistakes in this exercise is bending and straightening the arms. Do not straighten your arms when bringing your hands back; keep them under tension. This prevents you from having to bend them again on the way forward and thereby prevents excessive involvement of the biceps.

Another common mistake is intending to perform a cable (crossover) fly but instead turning it into a cable chest press. The hands then begin with the palms facing downward (pronated) instead of inward (neutral). The movement itself is then more of an upward push, as in the bench press, rather than an embracing movement.

As mentioned, you can turn a cable fly into a cable crossover fly by allowing the hands to cross each other. This can make balancing the exercise more difficult. Because of the width of the hands and handles, one arm will have to pass partly underneath or over the other. This should therefore be alternated. Crossing the hands makes the exercise technically more difficult and can distract from proper execution.

Keep the elbows below shoulder level in the starting and ending positions. This prevents excessive involvement and a potentially injury-prone shoulder position.

Do not bring the elbows too far back (actually 'downward' since you are lying down) at the beginning and end of the movement. They should not move far past the torso. A safe starting point is to bring them level with the torso. Depending on shoulder mobility, you can move slightly farther back for a larger range of motion.