Stability Ball Single Arm Dumbbell Fly
In SetGrip: Dumbbell Fly (Stability Ball, Single Arm)
Combining the ball bridge with a single dumbbell doubles the stability problem: your hips fight to stay level while the one-sided weight arcs away from your midline. Progress to it from the two-arm stability ball fly rather than from the bench single arm version, and expect the workable load to drop by more than you would guess.
How to do the Stability Ball Single Arm Dumbbell Fly
- Sit on an exercise ball with a dumbbell in one hand and your feet flat on the ground.
- Walk your feet forward, rolling the ball until your upper back is supported on the ball and your head, neck, and shoulders are off the ball.
- Extend your arm with the dumbbell straight up above your chest, palm facing inward.
- Slowly lower the dumbbell out to the side, keeping a slight bend in your elbow.
- Pause for a moment when your arm is parallel to the ground.
- Engage 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.
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.
Sets, reps and where it fits
| Goal | Sets × reps | Rest |
|---|---|---|
| Muscle growth | 3–4 × 10–15 per side | 60–90 s |
| Endurance / finisher | 2–3 × 15–20 per side | 45 s |
| Strength | Not ideal — pick a compound lift for the same muscle | — |
Flies are an isolation movement for after the pressing or rowing is done. Pair a cable crossover with a cable rear delt fly on the same station, or dumbbell chest flies with dumbbell rear delt flies on the same bench.
Variations and alternatives
Similar exercises
Frequently asked questions
What muscles does the Stability Ball Single Arm Dumbbell Fly work?
The Stability Ball Single Arm Dumbbell Fly primarily works the pectorals. It also involves the delts and triceps, which assist the movement and stabilise the joints.
Is the Stability Ball Single Arm Dumbbell Fly good for beginners?
Not as a starting point. The Stability Ball Single Arm Dumbbell Fly is rated advanced because it demands strength, mobility or coordination that takes time to build. Beginners should work up to it through the easier variations listed on this page.
What can I do instead of the Stability Ball Single Arm Dumbbell Fly?
If you cannot do the Stability Ball Single Arm Dumbbell Fly, try the Incline Stability Ball Single Arm Dumbbell Fly, the Stability Ball Dumbbell Fly or the Stability Ball Single Leg Dumbbell Fly. Each of them trains the pectorals through a similar movement, so you can swap them in without changing the rest of the workout.
How many sets and reps should I do?
It depends on your goal. For the Stability Ball Single Arm Dumbbell Fly, a sensible starting point is muscle growth: 3–4 × 10–15 per side with 60–90 s rest; endurance / finisher: 2–3 × 15–20 per side with 45 s rest. Do it after your compound lifts. It is a finishing movement, not the main event.
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