Reverse Flies: Targeting Rear Deltoids, Benefits, and Proper Execution

How do you do reverse flies with rear delts?

The reverse fly is a highly effective isolation exercise specifically designed to target the posterior (rear) head of the deltoid muscle, promoting balanced shoulder development and improved posture through controlled horizontal abduction of the arm.

Targeting the Posterior Deltoid with Reverse Flies

The rear deltoid is often the most underdeveloped head of the shoulder musculature, largely due to the emphasis on anterior (front) and medial (side) deltoid work in many common pressing and lateral raising exercises. Neglecting the rear deltoids can lead to muscular imbalances, compromised shoulder stability, and a rounded-shoulder posture. The reverse fly directly addresses this by isolating the posterior deltoid, ensuring comprehensive shoulder development and functional strength.

Anatomy and Function of the Rear Deltoid

The deltoid muscle is comprised of three distinct heads:

• Anterior (Front) Deltoid: Primarily responsible for shoulder flexion (raising the arm forward) and internal rotation.
• Medial (Side) Deltoid: Primarily responsible for shoulder abduction (raising the arm out to the side).
• Posterior (Rear) Deltoid: Originating from the spine of the scapula and inserting into the deltoid tuberosity of the humerus, its primary actions are horizontal abduction (pulling the arm backward and away from the body in the horizontal plane), external rotation, and shoulder extension.

The reverse fly mimics the horizontal abduction movement, directly engaging the posterior deltoid as the primary mover.

Benefits of Incorporating Reverse Flies

Integrating reverse flies into your training regimen offers several key advantages:

• Improved Posture: By strengthening the rear deltoids, reverse flies help pull the shoulders back, counteracting the common "desk posture" of rounded shoulders and forward head.
• Enhanced Shoulder Stability: A strong posterior deltoid contributes significantly to the overall stability of the glenohumeral (shoulder) joint, reducing the risk of dislocations and injuries.
• Balanced Shoulder Development: Addresses muscular imbalances between the front and rear deltoids, leading to more aesthetically pleasing and functionally sound shoulders.
• Injury Prevention: A balanced musculature around the shoulder joint can prevent impingement syndromes and other common shoulder issues often caused by overdeveloped anterior muscles and weak posterior ones.
• Supports Compound Lifts: A strong posterior chain, including the rear delts, supports performance in compound exercises like rows, pull-ups, and even bench presses by stabilizing the shoulder joint.

Proper Execution of the Dumbbell Bent-Over Reverse Fly

This is the most common and accessible variation, effectively targeting the rear delts.

• Setup:

  • Select a pair of light to moderate dumbbells. Remember, the rear deltoid is a smaller muscle, and heavy weight often leads to compensatory movements.
  • Stand with your feet shoulder-width apart, knees slightly bent.
  • Hinge forward at your hips, keeping your back straight and a neutral spine. Your torso should be nearly parallel to the floor, or at least at a 45-degree angle. Avoid rounding your lower back.
  • Let the dumbbells hang directly below your chest, arms extended but with a slight bend in the elbows. Your palms can face each other (neutral grip) or slightly pronated (palms facing back).

• Execution:

  • Initiate the movement by thinking about squeezing your shoulder blades together. Simultaneously, raise the dumbbells out to the sides in a wide arc, leading with your elbows.
  • Maintain the slight bend in your elbows throughout the movement. The movement should come from your shoulder joint, not your elbows flexing or extending.
  • Focus on feeling the contraction in your rear deltoids. Imagine pulling your elbows towards the ceiling.
  • Raise the dumbbells until your arms are roughly parallel to the floor or slightly above. Your body should form a "T" shape with your arms extended out.
  • Peak Contraction: Pause briefly at the top of the movement, consciously squeezing your rear deltoids.
  • Controlled Descent: Slowly and with control, lower the dumbbells back to the starting position, resisting gravity. Do not let them simply drop. Maintain tension in the rear deltoids throughout the eccentric (lowering) phase.

• Breathing: Exhale as you raise the dumbbells (concentric phase) and inhale as you lower them (eccentric phase).

Machine Reverse Fly (Pec Deck Rear Delt Fly)

Many gyms have a pec deck machine that allows for reverse flies. This variation offers more stability and constant tension.

• Setup:

  • Adjust the seat height so your shoulders are aligned with the machine's pivot point.
  • Grasp the handles, typically with a neutral grip (palms facing each other). Ensure your arms are extended but not locked.
  • Lean forward against the chest pad, maintaining a straight back.

• Execution:

  • Similar to the dumbbell version, push the handles out to the sides in a controlled arc, focusing on squeezing your shoulder blades and engaging your rear deltoids.
  • Control the movement both on the way out and on the slow, controlled return. Avoid letting the weight stack crash.

Common Mistakes to Avoid

• Using Excessive Weight: The most common error. Too much weight leads to momentum, engaging larger muscle groups like the traps and rhomboids, and reduces isolation of the rear deltoids. Prioritize form over load.
• Shrugging the Shoulders: If you feel the movement primarily in your upper traps (neck area), you're shrugging. Depress your shoulder blades and focus on pulling them back and together, not up.
• Loss of Spinal Neutrality: Rounding your back, especially in the bent-over dumbbell variation, puts undue stress on the lumbar spine. Maintain a straight, neutral spine throughout.
• Swinging or Using Momentum: This negates the purpose of the exercise. Each repetition should be controlled and deliberate, maximizing time under tension for the target muscle.
• Going Too Fast: Rushing through reps compromises the mind-muscle connection and reduces the effectiveness of the exercise. Focus on the squeeze and the slow eccentric.
• Leading with Hands Instead of Elbows: While subtle, thinking about leading with your elbows helps ensure the movement is driven by horizontal abduction, rather than just raising the hands.

Programming Considerations

• Sets and Reps: Due to the rear deltoid's smaller size and endurance-type fibers, it responds well to higher rep ranges. Aim for 3-4 sets of 10-20 repetitions.
• Frequency: You can effectively train rear delts 2-3 times per week, either as part of a shoulder workout, a "pull" day, or even a "push" day to ensure balanced development.
• Placement: Reverse flies are typically performed as an isolation exercise after your main compound movements (e.g., rows, overhead presses) when you can dedicate full attention to form and muscle activation.

Variations and Progressive Overload

• Incline Bench Dumbbell Reverse Fly: Performing the exercise lying face down on an incline bench provides stability and removes the strain on the lower back, allowing for greater focus on the rear delts.
• Cable Reverse Fly: Using a cable machine provides constant tension throughout the entire range of motion, which can be beneficial for muscle hypertrophy.
• Single-Arm Reverse Fly: Excellent for addressing muscular imbalances and improving unilateral strength and control.
• Progressive Overload: Once you can comfortably perform your target reps with perfect form, gradually increase the weight, increase the number of sets, or decrease rest times. Focus on improving the quality of contraction before adding significant load.

Conclusion

The reverse fly is an indispensable exercise for anyone serious about comprehensive shoulder development, injury prevention, and improved posture. By understanding the anatomy of the posterior deltoid and executing the movement with precision and control, you can effectively target this often-neglected muscle group. Remember, consistency and impeccable form are paramount to unlocking the full benefits of this powerful exercise.