Across Bench Single Arm Dumbbell Rear Delt Fly
In SetGrip: Dumbbell Rear Delt Fly (Across Bench, Single Arm)
- Secondary muscles
- Traps, Rhomboids
- Body part
- Shoulders
- Position
- Lying
- Laterality
- Unilateral (one arm at a time)
- Category
- Strength
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Lying chest-down across a flat bench with a single dumbbell parks your torso on the pad, so the low back holds nothing while one rear delt does all the work. Because you drape sideways across the bench, the free hand can grip the frame for stability, and each shoulder gets its own strict set to close left-right gaps.
How to do the Across Bench Single Arm Dumbbell Rear Delt Fly
- Lie face down on a flat bench with a dumbbell in one hand, palm facing inwards.
- Extend your arm straight down towards the floor, keeping it close to your body.
- Raise your arm up and back, squeezing your shoulder blade towards your spine.
- Pause for a moment at the top, then slowly lower your arm back down to the starting position.
- Repeat for the desired number of repetitions, then switch arms.
Tip: Lead with the elbows and think of reaching wide rather than lifting up.
Muscles worked
Primary
Delts · Shoulders
Front raises hit the front delt, lateral raises the side, and Y or rear raises the back head; whichever you pick, the burn should build across the top of the shoulder by the last few reps.
Secondary
- Traps — The upper traps will take over if you shrug, so a slight downward pull of the shoulders keeps them out of it.
- Rhomboids
Common mistakes
- Swinging from the hips — a small bounce at the bottom is the sign of a weight that is too heavy; lighten it and lift from a dead stop.
- Shrugging as you raise — the traps take over when the shoulders rise toward the ears; keep them down and lead with the elbows.
- Raising far above shoulder height — on lateral and front raises the upper traps take over past parallel, so stop around shoulder level unless the variation is built to go overhead.
- Locked elbows — keep a soft bend in the elbow throughout so the load stays on the shoulder rather than the joint.
Where it fits in a workout
Raises are accessory work and belong after the presses in a shoulder or push session. Superset lateral raises with a rear delt fly for a complete shoulder finisher.
How many sets, how heavy and how hard: see what the ACSM position stands support.
Variations and alternatives
Similar exercises
Without dumbbell
When to talk to someone
- Chest discomfort, feeling faint or lightheaded, or trouble breathing during or after exercise can be signs of a heart attack. In the US, call 911 right away; elsewhere, call your local emergency number.
- Heart, metabolic or kidney disease, or symptoms like these when you are active: talk to your doctor before you start or step up training.
- Pregnant: ask your obstetric care provider which exercise suits you.
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Sources
- ACSM position stand on exercise quantity and quality (Garber et al., 2011)
- ACSM preparticipation health screening (Riebe et al., 2015)
- ACOG Committee Opinion No. 804 on exercise in pregnancy (2020)
- CDC: About Heart Attack Symptoms, Risk, and Recovery (2024)
Sources checked on October 17, 2026. Full citations are in the exercise library.
Animation and exercise data: ExerciseDB, licensed to SetGrip. General information, not medical or coaching advice.