Rear Delt Fly
The rear delt fly targets the often-neglected posterior deltoids, crucial for shoulder health, posture, and complete shoulder development. It's essential for balanced shoulder aesthetics and function.
Muscles Worked
Primary Muscles
- Posterior Deltoids
Secondary Muscles
- Rhomboids
- Middle Trapezius
- Infraspinatus
How to Perform
Sit on the edge of a bench leaning forward with chest close to your thighs.
Hold dumbbells beneath your legs with palms facing each other and slight elbow bend.
Raise your arms out to the sides in an arc motion, leading with your elbows.
Focus on squeezing your shoulder blades together at the top of the movement.
Raise until upper arms are parallel to the ground, feeling contraction in rear delts.
Lower the dumbbells back to starting position with control, maintaining tension throughout.
Common Mistakes
Using Too Much Weight
Heavy weights force momentum use and reduce rear deltoid isolation and activation.
Not Maintaining Forward Lean
Sitting upright shifts emphasis away from rear delts to middle traps and rhomboids.
Bending Elbows During Movement
Changing elbow angle turns this into a rowing motion instead of a fly.
Stopping Short of Parallel
Not raising arms high enough reduces range of motion and rear deltoid contraction.
Training Notes
Rear Delt Fly is safest when the ribs stay down and the shoulder blades glide naturally. Avoid excessive arching by tightening the glutes and keeping the pelvis stacked. A neutral wrist and elbows slightly in front of the body keep the press in a strong, shoulder‑friendly line.
Use a controlled lowering phase to build stability. A 2–3 second eccentric helps the delts do the work rather than the traps. If you feel pinching, reduce range slightly and keep the elbows from drifting too far behind the body.
For hypertrophy, aim for 3–4 sets of 8–15 reps, leaving 1–2 reps in reserve. For strength, keep reps lower (5–8) and focus on crisp technique. Rest 90–150 seconds for moderate loads; longer for heavier sets.
If the traps take over, lower the load and think about “shoulders down and wide.” A slightly wider grip can reduce internal rotation stress during upright‑row type patterns. For raises, stop at shoulder height to avoid unnecessary joint strain.
Pair Rear Delt Fly with a rear‑delt or external‑rotation movement to balance the shoulder. A simple combo is a press plus face pulls or rear‑delt flyes. Over time, track reps and load while keeping the same smooth tempo.
Warm up with 1–2 lighter sets and some shoulder mobility before heavy work. Small adjustments—seat height, grip width, or range—can make a big difference in comfort and deltoid activation.
A slight scapular‑plane angle (about 30° forward of the body) is usually the most shoulder‑friendly for presses and raises. If your joint feels irritated, reduce range and keep the elbows slightly forward.
For lateral raises, think “long arms and soft elbows,” and stop when the hands reach shoulder height. Heavier weights tend to shift the work to the traps, so keep the load moderate and focus on tempo.
Balance your week with at least one rear‑delt movement and some external rotation work. This keeps the shoulder joint centered and reduces the risk of impingement over time.
Pro Tips
Use light weight and focus on the mind-muscle connection - rear delts respond better to higher reps.
Keep a slight bend in your elbows (about 10-15 degrees) and lock it in throughout.
Lead with your elbows and imagine pulling them back and apart rather than lifting with hands.
Aim for 12-20 reps per set with controlled tempo for optimal rear deltoid hypertrophy.
Variations
Use cables from high position for constant tension throughout movement.
Reverse Pec Deck
Machine variation allowing training to failure safely with fixed path.
Face Pull
Cable pulling movement that hits rear delts along with upper back muscles.
Alternative Exercises
Cable Rear Delt Fly
Cable variation providing constant tension throughout the range of motion.
Face Pull
Cable exercise targeting rear delts and upper back for shoulder health.
Reverse Pec Deck
Machine version with fixed path for safer training to muscular failure.
Bent-Over Row
Compound movement that works rear delts along with entire back.
Track Your Rear Delt Fly Progress
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