Dumbbell Chest Flys
Lie on a flat bench with the dumbbells above your chest, palms facing each other and elbows very slightly bent. Very slowly open your arms out to the sides in a wide arc, pause briefly at the bottom, then bring the dumbbells back over your chest along the same arc.
In the chest fly, your chest muscles sweep your arms towards the midline in a wide arc. Your elbow angle barely changes; all the movement happens at the shoulder. The exercise is a good addition to the dumbbell bench press.
Because of the arc, the load is greatest at the bottom, when your arms are wide open and your chest is stretched. At the top, above your chest, it becomes light. That is why the focus is on lowering slowly and pausing in the open position.
From the studio: For me, chest flys are an extremely valuable exercise for dumbbell training, at home and in the gym. My test for the right weight: you can hold the dumbbells at the bottom for 2 to 3 seconds with control. That is what I see in the studio.
Starting position
Lie on a flat bench as you would for the dumbbell bench press: back and head on the bench, feet planted firmly on the floor. Hold the dumbbells above your chest with your palms facing each other and your elbows very slightly bent.
Now open your arms very slowly out to the sides in a wide arc until your upper arms are roughly parallel to the floor, with the dumbbells out to the sides at chest level. Keep the same angle at your elbows the whole way. Hold for 2 to 3 seconds at the bottom.
Bring the dumbbells back together above your chest along the same arc. Grip the dumbbells firmly and brace your whole body.
The three cues
- Palms facing each other, elbows slightly bent
- Lower very slowly and pause at the bottom
- Grip hard, brace everything, arc back up
Common faults
| Fault | How to fix it |
|---|---|
| Moving too fast, using momentum | Lower very slowly and count 3, 2, 1 in your head. |
| The weight is too heavy and the dumbbells wobble at the bottom | Choose a weight you can hold steady at the bottom for 2 to 3 seconds. |
| Your elbows bend a lot on the way down | Keep your arms very slightly bent throughout, with the same elbow angle the whole way. |
| A loose grip, your body slack on the bench | Grip the dumbbells firmly and brace everything. |
Variations
| Variation | When to use it |
|---|---|
| Light dumbbells | Lower slowly, counting 3, 2, 1 in your head, then arc back up. Move on once the movement stays smooth. |
| Slow chest flys with a pause | Hold for 2 to 3 seconds at the bottom with control, then arc back up. |
| Heavier dumbbells | Increase the weight in small steps, as long as you can still hold at the bottom for 2 to 3 seconds with control. |
Reps and load
Around 8 to 12 reps, slow, with a short pause at the bottom. Choose a weight that lets you stay in control in the open position.
The exercise fits well after the dumbbell bench press.
Which muscles do the work
| Muscle | Role | What it does here |
|---|---|---|
| Chest M. pectoralis major | Prime mover | Sweeps the arms towards the midline and controls the way down |
| Front delt M. deltoideus pars clavicularis | Synergist | Helps the chest bring the arm up and in over the chest |
| Biceps M. biceps brachii | Stabiliser | Holds the slight bend in the elbow |
| Rotator cuff Mm. supraspinatus, infraspinatus, subscapularis, teres minor | Stabiliser | Keeps the head of the upper arm centred in the socket |
| Forearms Mm. flexores antebrachii | Stabiliser | Hold the dumbbells with a firm grip |
| Abs M. rectus abdominis, Mm. obliqui | Stabiliser | Keep the trunk braced on the bench |
Your chest does the main work, with the front delts helping. Your biceps hold the elbow angle, your rotator cuff keeps the shoulder centred, and a firm grip adds tension around the shoulder.
Explained in full
Andreas explains why he values chest flys so highly, shows the starting position and the slow lowering with a pause, and what to focus on with your grip. · 2:10
Seeing it done right is not the same as doing it right
Video, cues and variations take you a long way. What they cannot give you is an outside eye at the moment the movement isn't quite there yet. That is what training with me is for — in the studio or in a workshop.
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Sources
Solstad TE, Andersen V, Shaw M, Hoel EM, Vonheim A, Saeterbakken AH. (2020). A comparison of muscle activation between barbell bench press and dumbbell flyes in resistance-trained males. J Sports Sci Med 19(4):645–651. PMC7675616 — Compares the barbell bench press and dumbbell flyes in 17 trained men (about 23 years old) at 6-rep maximum loads. The bench press produced higher chest, front-delt and triceps activity across most phases (8 to 81%), the fly higher biceps activity (57 to 86%). The authors recommend both exercises with the emphasis on the bench press. The basis for calling the fly a good addition to the dumbbell bench press and for listing the biceps as a stabiliser. Transfer to 40- to 60-year-olds training 2 to 4 hours a week: limited, with young trained men; with little time, it supports using flys as an addition. (Evidence type: EMG)
Welsch EA, Bird M, Mayhew JL. (2005). Electromyographic activity of the pectoralis major and anterior deltoid muscles during three upper-body lifts. J Strength Cond Res 19(2):449–452. DOI: 10.1519/14513.1 — Measures chest and front-delt activity in 12 college-age men and women during the barbell bench press, dumbbell bench press and dumbbell fly (6-rep maximum). Activation did not differ significantly, but in the fly the muscles were highly active over a shorter part of the movement. The basis for the chest and front delts in the table and for saying the load is not the same along the whole arc. Transfer: limited, with a small, young sample. (Evidence type: EMG)
Paoli A, Gentil P, Moro T, Marcolin G, Bianco A. (2017). Resistance training with single vs. multi-joint exercises at equal total load volume: effects on body composition, cardiorespiratory fitness, and muscle strength. Front Physiol 8:1105. DOI: 10.3389/fphys.2017.01105 — An 8-week study in 36 active men, three times a week, with equal volume of single-joint or multi-joint exercises. Both groups gained the same lean mass; strength rose more with multi-joint exercises. The basis for positioning flys as an addition to pressing. Transfer: limited, with young men. (Evidence type: Intervention study)
Sporrong H, Palmerud G, Herberts P. (1996). Hand grip increases shoulder muscle activity. An EMG analysis with static hand contractions in 9 subjects. Acta Orthop Scand 67(5):485–490. DOI: 10.3109/17453679608996674 — Measures shoulder muscle activity in 9 healthy people during a static hand grip at 30 and 50% of maximum in eight arm positions. A firm grip raised rotator cuff activity more than that of the larger shoulder muscles; the deltoid was sometimes less active in high arm positions. The basis for saying a firm grip adds tension around the shoulder and for listing the rotator cuff. No fly was measured, and the setting was a static lab task. Transfer: limited. (Evidence type: EMG)
Pedrosa GF, Pereira MR, Kassiano W. (2026). The interplay between muscle length, range of motion, and exercise selection: a review. Sports Med Int Open 10:a27337605. DOI: 10.1055/a-2733-7605 — A narrative review: training at longer muscle lengths appears to produce more growth, especially when meaningful external resistance acts in the stretched position. Background to the load in a fly being greatest when the chest is stretched. Not a fly study; the underlying research covers other muscles and mostly younger people. Transfer: as context. (Evidence type: Narrative review)
A note on context: EMG studies show which muscles an exercise recruits — that is a good reason to pick it, but it does not replace adjusting things to the person in front of you. See a doctor for persistent or severe pain.