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Dumbbell Single-Arm Chest Fly

Intermediate
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Unilateral dumbbell fly variation that isolates the chest with a deep stretch, targeting pectorals to build hypertrophy and address imbalances; requires core stability to resist rotation.

About Exercise

Equipment

Dumbbells, Flat Bench

Difficulty

2/5 • Intermediate

Primary Muscle Groups

Chest

Secondary Muscles

Triceps, Abs, Obliques

Popularity Score

7

Goals

Hypertrophy
Strength

Training Style

Bodybuilding

Setup Requirements

Requires Rack

No

Requires Bench

Yes

Requires Spotter

No

Space Needed

Small

Noise Level

Low

Muscle Breakdown

Chest

10/10

Mid Chest

Shoulders

6/10

Anterior Delts

Triceps

4/10

Abs

3/10

Obliques

3/10
Programming

Typical Rep Range

8-15 reps

Rest Between Sets

60-90 seconds

How to Perform

Lie supine on a flat bench with feet flat on the floor. Hold a dumbbell in one hand above your chest with a slight elbow bend; place the other hand on your ribcage for stability.

  1. Inhale and lower the dumbbell in a wide arc until your arm is parallel to the ground.
  2. Keep a slight bend in your elbow throughout the movement.
  3. Exhale and squeeze your chest to arc the dumbbell back to the starting position.
  4. Maintain core engagement to prevent torso rotation.
  5. Switch arms after completing reps on one side.

Coaching Tips

Form Cues

  • Keep elbows slightly bent
  • Squeeze chest at the top
  • Pack shoulders down
  • Engage core tight
  • Arc the path wide
  • Feel the stretch deep

Breathing

Inhale during the lowering phase; exhale as you lift the dumbbell by contracting your chest.

Tempo

3-1-2

Range of Motion

Lower until the dumbbell is level with your chest and arm parallel to the floor; fully extend to the top without locking elbows.

Safety

Safety Notes

  • Avoid if acute shoulder pain or impingement exists
  • Do not exceed comfortable chest stretch
  • Use lighter weight to master form
  • Keep lower back pressed into bench
  • Stop if shoulder joint feels unstable

Spotting

Spot from behind the working arm to assist on the lift if needed; not typically required for moderate weights.

Common Mistakes

  • Locking elbows during movement
  • Lowering too far past shoulder level
  • Using momentum to swing the weight
  • Allowing torso to rotate or arch
  • Gripping too tightly on dumbbell

When to Avoid

  • Shoulder impingement
  • Recent rotator cuff injury
  • Elbow joint instability

Flexibility Needed

  • Shoulder horizontal adduction
  • Thoracic extension

Build Up First

  • Basic chest fly form
  • Core stability awareness

Also known as

One-Arm Dumbbell Fly, Single-Arm DB Chest Fly, Unilateral Dumbbell Fly

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