One-Arm Flat Bench Dumbbell Flye

One-Arm Flat Bench Dumbbell Flye is a resistance exercise - shoulder horizontal adduction exercise involving Pectoralis major. Use these steps to learn the movement and work with your coach to choose a suitable level.

Last updated: 2026-10-31 · DynPerformance

Primary muscles: Pectoralis major
Secondary muscles: Anterior deltoid, Serratus anterior, Biceps brachii (stabilization)
Exercise type: Resistance exercise - shoulder horizontal adduction

Exercise technique

Move the load
Use your thigh to help bring the dumbbell over your chest.
Lie down
Plant your feet on the floor and settle your back on the bench.
Free hand
Hold the edge of the bench for balance.
Elbow position
Maintain a slight bend in the working arm.
Open
Lower the dumbbell out to the side in a wide arc.
Lower limit
Open only as far as you can control your shoulder without rotating your torso.
Close
Reverse the same arc to bring the weight over your chest.

Key technique points

Stabilize your pelvis under the one-sided load.
Do not take the dumbbell past the midline of your torso.
Do not change your elbow angle as you would in a press.
Do not suddenly release the support of your free hand.
Keep equal shoulder contact with the bench.
Do not move the dumbbell behind your head.

Common mistakes

Torso rotation

This turns a one-arm fly into a whole-body movement.

Pressing elbow action

This shortens the fly arc.

Excessive depth

This exceeds your shoulder-control limit.

Crossing the midline

This shifts the balancing load to the other side.

Lifting the hips

This disrupts support on the bench.

Fast reversal

This uses momentum instead of the chest muscles.

Frequently asked questions