Decline Single Arm Dumbbell Fly
In SetGrip: Dumbbell Fly (Decline, Single Arm)
- Secondary muscles
- Delts
- Body part
- Chest
- Position
- Lying
- Laterality
- Unilateral (one arm at a time)
- Category
- Strength
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Holding one dumbbell while lying head-down puts an offset load on your torso, so your obliques fight to keep you square on the bench while the working pec handles the fly. Reserve it for after you own the two-arm decline dumbbell fly, and start well lighter than half of what you would use for the pair.
How to do the Decline Single Arm Dumbbell Fly
- Lie down on a decline bench with a dumbbell in one hand, resting it on your thigh.
- Using your thigh to help raise the dumbbell, lift it up to shoulder width with your palm facing your torso.
- Rotate your wrist so that the palm of your hand is facing forward.
- As you breathe in, lower the dumbbell slowly to the side until you feel a stretch in your chest.
- Exhale and use your chest muscles to bring the dumbbell back up to the starting position.
- Repeat for the desired number of repetitions, then switch arms.
Tip: Imagine hugging a barrel rather than pushing a weight.
Muscles worked
Primary
Pectorals · Chest
On chest flies and cable crossovers the pecs pull the arms together in an arc and should feel a deep stretch at the bottom and a hard squeeze at the top.
Secondary
- Delts — Rear delt flies work the back of the shoulder as the arms swing wide, and the front delt assists on any chest fly.
Common mistakes
- Elbows bending as you tire — this turns a fly into a press; set the elbow angle at the start and keep it constant for the whole set.
- Going too heavy — flies are a stretch and squeeze movement, not a strength lift; you should be able to pause at the bottom without the shoulders rolling forward.
- Stopping short of the stretch — let the arms open until you feel the chest or rear delts lengthen, then bring them back under control.
- Not squeezing at the finish — the last few inches are where the muscle shortens most, so hold the contraction for a count before opening again.
Where it fits in a workout
Flies are an isolation movement for after the pressing or rowing is done. Pair a chest fly with a rear delt fly for a balanced superset.
How many sets, how heavy and how hard: see what the ACSM position stands support.
Variations and alternatives
Similar exercises
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.