Cable Chest Fly: Muscles Worked and More

In a more technical sense, the cable chest fly is classified as a bilateral open chain isolation exercise requiring the use of a pair of cable towers.

During traditional resistance training programming, the cable chest fly is used as a hypertrophy-focused accessory movement, rather than as the main source of pectoral training stimulus. 

Such a role is due to its relatively low loading capacity, where the actual intensity of the movement is limited by the lifter’s positioning and the fact that arm adduction can only be safely executed with so much force.

In the majority of cases, the cable chest fly is performed in a standing position with the legs staggered - however, it may also be done in a seated position, so long as the trunk is appropriately angled and the range of motion is not limited by the seat itself.

How to Do a Cable Chest Fly

To perform a repetition of the cable chest fly, the lifter begins by first adjusting both cable pulleys to around head-height, placing themselves an even distance between them as they grip the handles.

The legs should be staggered for greater stability as the trunk is leaned several degrees forwards at the waist. The arms themselves should be horizontally parallel to the shoulders, but vertically below them.

Keeping the elbows only slightly bent, the lifter then contracts their chest and rotates their arms towards the front of their chest - keeping them outstretched and avoiding any contraction of the biceps as they do so.

Once the arms are just shy of touching at the front of the torso, the lifter allows the resistance of the cable to slowly pull their arms back around - keeping tension in their chest as they do so.

With the arms once again parallel to the sides of the body, the repetition is considered to be complete.

For the best results, ensure that the scapula is partially retracted and that the trunk is not completely vertical in angle.

Sets and Reps Recommendation:

Because it can be difficult (and even dangerous) to perform cable flys with too much weight, lifters will need to rely on tension and volume to get the most out of the exercise.

2-4 sets of 12-16 repetitions is a good range for pectoral muscle hypertrophy.

What Muscles are Worked by Cable Chest Flys?

The cable chest fly is classified as an isolation exercise, meaning that it is only meant to target a single muscle group alone. This group, of course, is the pectoral muscle group located along the chest.

The pectoral muscles are primarily divided into the pectoralis major and minor, with the pectoralis major itself featuring a clavicular (upper) head and a sternal (lower) head. 

Depending on the orientation of the trunk and the position of the arms, either pectoralis major head may be emphasized slightly more during a cable fly repetition. Generally, we will want to aim for only a 5-10 degree incline to the trunk so as to target both in equal measure.

Common Cable Chest Fly Mistakes to Avoid

Although cable chest flys are indeed quite safe to perform, the following common mistakes should be avoided for better chest development.

Allowing the Hands to Touch

Muscular hypertrophy is best achieved through a constant level of tension within the muscle. 

Within the specific movement pattern of the cable chest fly, allowing the hands to touch together can relieve tension in the pectoral muscles, reducing the effectiveness of the exercise to a certain extent. 

In order to get the most out of your training, the hands (and handles) should stop just shy of touching as the arms are adducted to the front of the trunk. 

Fully Extending the Elbows

While it is indeed good technique to keep the arms straight throughout the entire chest fly set, completely extending the elbows so as to lock them out will greatly increase risk of injury and may shift emphasis to the anterior deltoids instead.

An ideal cable chest fly set will feature only a mild bend to the elbows, whereas the rest of the arm should remain relatively straight.

Involving the Biceps

Unlike fully extending the elbows, allowing for excessive elbow flexion can cause a shift towards the elbow flexor muscles instead - particularly the biceps, especially when using a neutral or underhand grip.

Considering that the cable chest fly is meant to solely target the chest, lifters will wish to avoid accidentally activating their biceps as much as possible.

To do so, the arms must remain straight while simultaneously avoiding locking out the elbow. 

Other factors that can help reduce biceps involvement are using an overhand grip or ensuring that the trunk is angled several degrees forwards, allowing for greater pectoral contraction.

Finally, if all other attempts fail, the lifter can instead make use of cable wrist wrap attachments so as to take the hands out of the equation and greatly reduce the involvement of any arm muscles.

Upper Arms are Above the Shoulders

To reduce friction within the shoulder joint and mitigate the risk of impingement, the upper arms should be below the shoulders throughout the entire set. 

Allowing the elbows or upper arms to rise to a higher elevation than the shoulders themselves will create a poor angle to the humerus within the shoulder joint, increasing irritation of the labrum and possibly leading to acute damage.

In most cases, the cable chest fly being performed this way is simply a sign that the pulleys have been set too high - or that the lifter is failing to control their scapula, leading to a shrugging motion.

Arching the Lower Back or Hunching the Shoulders

Though caused by drastically different mechanics, the presence of either a lower back arch or hunched shoulders are similar enough in effect to be grouped together beneath the wing of poor trunk positioning.

Arching the lower back forwards into a flexed state can lead to instability and present a risk of lower back strain, whereas hunching the shoulders either forwards or upwards is a sign of poor scapula positioning and a loss of pectoral muscle emphasis.

In either case, the lifter can correct such issues by properly engaging their core, partially retracting their scapula and ensuring their chest is pushed outwards throughout the entire set. Adopting a staggered foot positioning will also aid in maintaining stability while in this stance.

Alternatives and Variations of the Cable Chest Fly

If the cable chest fly is a bit too nonspecific for your needs, try the following variations and alternatives out.

High to Low Cable Chest Flys

The high to low cable chest fly is simply a conventional cable chest fly performed with the pulleys set higher than they would ordinarily be. This alters the angle of resistance, creating greater emphasis on the sternal head of the pectoralis major.

Apart from being better for targeting your lower chest, the high to low variant is also excellent for eliminating the involvement of muscles that may be otherwise accidentally contracted - especially the biceps and other elbow flexor muscles.

Otherwise, apart from the aforementioned advantages, the high to low cable fly is much the same as its conventional counterpart in movement pattern and role.

Incline Cable Chest Flys

The incline cable chest fly is a variation of lying chest fly where the lifter lies atop an incline bench - allowing for greater emphasis on the clavicular (upper) head of the pectoralis major and a slightly larger range of motion.

Because the exercise is done in a lying position, it is comparatively more strict in terms of stance and stability, and can provide a ready alternative for lifters that have difficulty performing conventional cable flys in a standing position.

Cable Chest Press

The cable chest press is less so a chest fly variation and instead a more intense substitute that includes the anterior deltoids and triceps brachii alongside the pectorals.

Furthermore, apart from simply utilizing arm adduction, the cable chest press will also include elbow extension as the overall movement pattern is a literal horizontal press, rather than a fly.

As a substitute exercise, the cable chest press is best used when no compound movement involving the chest is performed within the cable chest fly’s workout session. 

Frequently Asked Questions (FAQ)

Are Cable Flys Good for the Chest?

Yes - cable flys are excellent for working and developing the pectoral muscles in isolation. 

When paired with a properly structured training program, the cable chest fly will lead to a far stronger and muscular chest.

What is the Best Angle for Cable Chest Flys?

The best angle for cable chest flys is one that fits your specific training needs. 

If you have no specific desire to emphasize the upper or lower head of your pectoralis major, then an angle that sets the cables at approximately shoulder-level is ideal.

Should You Do Chest Flys Heavy or Light?

Chest flys are difficult to perform correctly with excessively heavy amounts of weight. 

What’s more - the fact that they isolate the pectoral muscles means that overloading the exercise can easily lead to injury if your form is suboptimal.

Essentially, the chest fly is an exercise best done with a light or moderate amount of weight and volumes in the higher repetition range.

References

1. López-Vivancos, Abraham, Noelia González-Gálvez, Francisco Javier Orquín-Castrillón, Rodrigo Gomes de Souza Vale, and Pablo Jorge Marcos-Pardo. 2023. "Electromyographic Activity of the Pectoralis Major Muscle during Traditional Bench Press and Other Variants of Pectoral Exercises: A Systematic Review and Meta-Analysis" Applied Sciences 13, no. 8: 5203. https://doi.org/10.3390/app13085203

2. Jagessar, Miguel & Gray, Michael. (2009). Optimizing Development of the Pectoralis Major. 

3. Schütz, Pascal, Pia Zimmer, Fabian Zeidler, Michael Plüss, Katja Oberhofer, Renate List, and Silvio Rene Lorenzetti. 2022. "Chest Exercises: Movement and Loading of Shoulder, Elbow and Wrist Joints" Sports 10, no. 2: 19. https://doi.org/10.3390/sports10020019