Flat Dumbbell Fly
The flat fly isolates the pec by removing the triceps from the equation, so the chest does the entire job of pulling the arms together. It shines for building the stretch-loaded portion of the movement and delivering a strong squeeze at the top. Program it after your presses as focused chest volume rather than a heavy strength lift.
- Body part
- Chest
- Type
- Strength
- Browse by muscle
- Pectoralis Major Sternocostal
- Browse by movement
- Horizontal Adduction
- Target
- Pectoralis Major Sternocostal
- Secondary
- Pectoralis Major Clavicular, Deltoid Anterior
- Tertiary
- Biceps Brachii Short Head
How to do it
- 1
Lie on a flat bench holding a dumbbell in each hand over your chest, palms facing each other.
- 2
Keep a slight, fixed bend in your elbows and lower the dumbbells out in a wide arc.
- 3
Lower until you feel a stretch across the chest and your upper arms are about level with the bench.
- 4
Squeeze your chest to draw the dumbbells back together along the same path.
- 5
Stop just short of the dumbbells touching to keep tension on the pecs.
Tips
- Maintain the same elbow bend from start to finish; straightening and bending turns it into a poor press.
- Go lighter than you expect; the long lever makes flyes deceptively demanding.
- Keep your shoulder blades pulled back so the chest, not the front of the shoulder, takes the stretch.
Variations
Common mistakes
- The dumbbells clack together at the top, which parks the tension on your joints for a moment; stop an inch or two short and keep the pecs loaded.
- There is no way to bail out of a fly the way you can with a press, so the pair you pick has to be one you can bring back over your chest from the widest point; check that on the first rep.
- The arc narrows to a short up-and-down path over the sternum once the weight is heavy, so the pec never travels through any real distance.
- As the reps get hard the hips lift off the bench to help; keep your backside on the pad and drop to a lighter pair.
Frequently asked
- How many reps of the flat dumbbell fly should you do when you are new to the exercise?
- Start at 6 to 8 kg per hand for three sets of 12 to 15, which feels absurdly light next to a bench press and is exactly right here. The last two reps should slow down while the arc stays as wide as it was on rep one. Once 15 reps hold up on all three sets, move to the next pair up.
- What can I do instead of the flat dumbbell fly with no dumbbells?
- Hook a band behind you at around chest height and you get the same hugging arc, with tension that holds on at the top where the dumbbells would have quit. Failing that, push-ups with a slow three-second lower cover mid-chest work; they bring the triceps back in, so treat them as a substitute for the session rather than a matched swap.
- What is the flat dumbbell fly for, and who should skip it?
- It is isolation for the mid chest, useful after pressing when you want more chest volume without piling on triceps fatigue. It is not where beginners should spend their first months, since presses build more for the same effort. Anyone whose shoulder pinches in the stretched position is better served by a machine or cable version, where the range can stop wherever it stays comfortable.
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