Reverse Fly

Reverse flyes performed on a fly machine targets the posterior deltoid (also referred to as “rear deltoids”). This exercise is performed seated backward on the fly machine while pushing resistance backward with arms out to the side.

The concentric portion of the lift is horizontal shoulder abduction. The eccentric portion is horizontal shoulder adduction as the weight is lowered.

The purpose of the reverse flyes on a machine is to strengthen the posterior deltoid while also promoting the hypertrophy (increases in size) of this muscle.

Reverse flyes performed on a chest fly machine activates the posterior deltoid, as it is the primary horizontal shoulder abductor. Activating the posterior deltoid contributes to the overall hypertrophy of the shoulder muscles, providing roundness and a fuller appearance.

Although it is primarily an exercise for aesthetics, reverse flyes also serve as an auxiliary exercise that can increase strength involved in other multi-joint exercises.

Performing this exercise in a seated position with the chest supported by the back pad allows the lifter to isolate the contraction of the deltoid. The pulley system of the machine also provides a uniform resistance throughout the entire range of motion.

The deltoid is a thick, multipennate muscle that forms a curtain around the shoulder. It is the primary muscle involved with arm abduction and the posterior fibers are a primary horizontal shoulder abductor. When developed, the deltoids give the shoulder their round shape. The origin of the deltoid is located at the insertion of the trapezius, lateral third of the clavicle and the acromion spine of the scapula. Its insertion is located at the deltoid tuberosity of the humerus.

The infraspinatus is one of the four rotator cuff muscles. Partially covered by the deltoid and trapezius, it assists with horizontal shoulder abduction. Its origin is located at the infraspinous fossa of the scapula. Its insertion is located at the greater tubercle of the humerus, near the insertion sites of the supraspinatus and teres minor.

The teres minor is also a rotator cuff muscle that can be regarded as the “sidekick” to the infraspinatus. It is located just below the infraspinatus and may be inseparable from the infraspinatus. It comes as no surprise that the teres minor performs the same actions as the infraspinatus. Its origin is located at the lateral border of the dorsal subscapular surface. Its insertion is located just below that of the infraspinatus on the greater tubercle of the humerus.

The latissimus dorsi, rhomboids, wrist extensors and other two rotator cuff muscles (i.e. supraspinatus and subscapularis) play an essential role in stabilizing the wrists, forearms and shoulders during this exercise.

Bent over lateral raise, incline bench lateral raise, bent over cable lateral raise, high cable reverse fly.

If the chest fly machine is equipped with horizontal and vertical handles, periodically rotate your wrists to stress your deltoid from an additional angle, optimizing hypertrophy.

Perform this movement (horizontal shoulder abduction) for posterior deltoids with free weights and from different positions such as on in incline bench (incline bench lateral raise) and standing straight with a cable (high cable reverse fly).

Focus on the concentric portion of the contraction, concentrating on “squeezing” as the arms approach shoulder level.

Emphasis on eccentric contractions, prolonging the eccentric portion of the contraction, may also be incorporated in a training program focused on increasing strength. This should be implemented accordingly and with adequate muscle recovery as eccentric contractions cause substantial damage to muscle tissue.

It’s important to note that your repetition and set volume will depend on your goals (e.g. strength, hypertrophy, muscular endurance). It is also important to allow adequate recovery days in between shoulder training days to allow muscles to repair.

Raising the hands above the level of the elbow and shoulder can minimize the activation of the deltoid and place negative stress on the shoulder joint. Adjust the seat height accordingly to ensure the handles are in line with your shoulders.

Swinging the torso and/or moving the legs or neck throughout the movement minimize the activation of the working muscles and increase the risk for injury. Do not use body momentum to lift the weight during concentric phases. Do not drop the weight on its way down. The concentric and eccentric phases should be controlled.

If the lifter has a compromised range of motion with the shoulder joint and/or performs this exercise incorrectly, this exercise can increase the risk of injury and/or exacerbate a previous injury. Performing this exercise with a weight too heavy for the lifter can also increase the risk for injury.

If proper technique and recovery are not adhered to, impingement syndrome, rotator cuff injuries, and glenoid labrum tears may result.

Lifters with a history of shoulder injury or present state of injury should consult with a physical therapist or orthopedic physician before performing this exercise.