Rear Delt Fly (Dumbbell)

Muscles Worked

How to Perform

1. 1

   Select a pair of light to moderate dumbbells. Start with lighter weight than you think you need, as the rear delts are small muscles that fatigue quickly and proper form is essential.

2. 2

   Stand with feet shoulder-width apart, holding a dumbbell in each hand with a neutral grip (palms facing each other). Hinge forward at the hips until your torso is nearly parallel to the floor, approximately 70-90 degrees.

3. 3

   Keep your back straight with a neutral spine, engage your core for stability, and allow the dumbbells to hang directly beneath your shoulders with a slight bend in your elbows. This is your starting position.

4. 4

   While maintaining the slight bend in your elbows, raise the dumbbells out to your sides in a wide arc. Lead with your elbows and focus on squeezing your shoulder blades together at the top of the movement.

5. 5

   Lift the dumbbells until your arms are roughly parallel to the floor or slightly higher, forming a "T" shape with your body. At the top, pause for a one-second count to emphasize the peak contraction.

6. 6

   Lower the dumbbells back to the starting position with control, taking 2-3 seconds for the eccentric phase. Maintain tension in your rear delts throughout the descent.

7. 7

   Repeat for the prescribed number of reps, maintaining your bent-over position throughout. Exhale as you lift the weights and inhale as you lower them.

Common Mistakes

• Rounding the Lower Back

  Allowing your spine to round forward places excessive stress on your lower back and reduces the effectiveness of the exercise. Maintain a neutral spine throughout by engaging your core and keeping your chest up. If you can't maintain proper posture, reduce the weight or perform the exercise on an incline bench for added support.

• Using Momentum and Swinging

  Jerking the weights up or using body momentum to lift the dumbbells defeats the purpose of this isolation exercise. The rear delts are small muscles that respond best to controlled, deliberate movements. If you need momentum to complete reps, the weight is too heavy and you're likely recruiting other muscle groups instead of isolating the target area.

• Not Maintaining Elbow Position

  Straightening your arms completely or bending your elbows excessively during the movement shifts tension away from the rear delts. Keep a consistent, slight bend in your elbows (about 10-20 degrees) locked throughout the entire range of motion. This fixed angle ensures the movement comes from shoulder transverse abduction, not elbow flexion.

• Lifting Too High

  Raising the dumbbells far above parallel to the floor causes the traps to take over and reduces rear delt activation. Stop when your upper arms reach parallel or just slightly above. The focus should be on horizontal abduction, not elevation, to keep constant tension on the posterior deltoids.

Pro Tips

• Use an Incline Bench for Better Stability

  Set an adjustable bench to 30-45 degrees and lie chest-down on it while performing rear delt flies. This variation eliminates lower back strain, provides stable support, and allows you to focus entirely on the rear delts without worrying about maintaining the bent-over position. It's particularly beneficial for beginners or those with lower back issues.

• Point Your Thumbs Down at the Top

  As you reach the top of the movement, rotate your wrists slightly so your thumbs point toward the floor. This internal rotation maximally contracts the rear deltoid fibers and eliminates any upper trap involvement. Many advanced lifters swear by this technique for enhanced rear delt activation.

• Prioritize Higher Reps

  The rear delts respond exceptionally well to higher rep ranges of 12-20 reps per set. These smaller muscles have a higher proportion of slow-twitch fibers and benefit from longer time under tension rather than heavy loads. Focus on feeling the burn and achieving a strong pump rather than chasing weight increases.

• Perform Them Early in Your Workout

  Since rear delts are often overlooked and underdeveloped, consider training them first in your shoulder workout when you're fresh and can maintain perfect form. This ensures they receive adequate attention and stimulus before fatigue sets in from compound pressing movements.

Variations

Adjust your dumbbell rear delt fly technique with these variations to challenge your muscles in new ways.

• Seated Bent-Over Rear Delt Fly

  Sit on the edge of a bench with feet together, bend forward at the hips, and perform the fly movement. This removes the lower body entirely from the equation and increases isolation.

• Single-Arm Dumbbell Rear Delt Fly

  Perform the exercise one arm at a time while supporting yourself with your free hand on a bench or rack. This unilateral approach helps correct muscle imbalances and allows greater focus on each side.

• Incline Bench Rear Delt Fly

  Lie chest-down on an incline bench set to 30-45 degrees. This is the most popular variation as it provides excellent back support and allows complete focus on the rear delts without lower back fatigue.

• Flat Bench Rear Delt Fly

  Lie face-down on a flat bench with arms hanging straight down. This variation changes the resistance angle and provides continuous tension throughout the movement without any rest at the bottom.

Alternative Exercises

These exercises target the same muscle groups and can serve as effective substitutes when dumbbells aren't available.

• Cable Rear Delt Fly

  Perform the movement using a cable crossover machine for constant tension throughout the entire range of motion. Cables are excellent for drop sets and maintaining consistent resistance.

• Reverse Pec Deck Machine

  A machine-based rear delt exercise that provides a fixed movement pattern and allows you to focus purely on the contraction without worrying about balance or form breakdown.

• Face Pulls

  A more compound movement that targets rear delts along with the middle traps and external rotators. Particularly valuable for shoulder health and posture improvement.

• Resistance Band Rear Delt Fly

  Use resistance bands anchored at shoulder height to perform the fly movement. Perfect for home workouts or as a high-rep finisher to achieve a deep muscle pump.