Dumbbell Single Arm Alternate Fly
- Synergistenmuskeln
- Biceps Brachii, Deltoid Anterior
- Equipment
- Dumbbell
- Körperregion
- Chest
- Typ
- Strength
The dumbbell single arm alternate fly is a lying chest exercise that works one side at a time, targeting the chest (pectoralis major, both the clavicular and sternal heads) with help from the front deltoids and biceps. Working one arm per rep lets you focus on a deep, controlled stretch and an even contraction on each side, making it useful for ironing out left-to-right strength differences.
Dumbbell Single Arm Alternate Fly: So führst du sie aus
- 1Sit on the end of a flat bench with a dumbbell in each hand resting on your thighs, then lie back so the dumbbells are at chest level.
- 2Press both dumbbells up over your chest with a neutral grip (palms facing each other) and a slight bend in your elbows.
- 3Plant your feet flat on the floor and pull your shoulder blades down and together against the bench.
- 4Keeping the other arm locked in place over your chest, lower one dumbbell out to the side in a wide arc, leading with your elbow until you feel a stretch across your chest.
- 5Stop the dumbbell roughly level with your shoulder, keeping the same soft elbow bend throughout the arc.
- 6Squeeze your chest to bring that dumbbell back up over your chest along the same arc until it meets the resting arm.
- 7Repeat with the opposite arm, then continue alternating sides for your target reps.
- 8Once finished, walk the dumbbells back to your thighs, sit up, and set them down with control.
Technik-Tipps
- Keep a fixed, slight elbow bend through the whole arc — open the elbows further only if your shoulders feel strained, and never let the arms straighten into a press.
- Move slowly on the lowering phase of each rep; the controlled stretch is where most of the chest work happens.
- Keep the non-working dumbbell stacked directly over your chest so your torso stays square and you don't twist toward the moving side.
- Exhale as you bring the dumbbell up and inhale as you lower it, keeping your upper back tight against the bench.
- Start lighter than you would for a two-arm fly — the uneven load and longer time under tension make this harder than it looks.
Häufige Fehler
- Lowering the dumbbell too far below shoulder level, which over-stretches the shoulder joint and risks injury.
- Bending and straightening the elbow through the rep, which turns the fly into a pressing motion and shifts work off the chest.
- Rotating the torso toward the working arm, which cheats the rep and loads the spine unevenly.
- Using too much weight so the dumbbell drops fast instead of being lowered under control, losing tension on the chest.
- Letting the resting arm drift or drop instead of holding it locked over the chest, so the bench support and torso position break down.
Häufig gestellte Fragen
What muscles does the dumbbell single arm alternate fly work?
It mainly works the chest (pectoralis major, both the clavicular and sternal heads), with the front deltoids and biceps assisting to control the dumbbell through the arc.
Why do one arm at a time instead of both together?
Alternating arms lets you focus on each side individually, which helps even out left-to-right strength and size differences and gives you a longer, more controlled stretch per rep.
How many sets and reps should I do?
For most lifters, 3 to 4 sets of 10 to 12 reps per arm with a moderate weight works well. Because it's an isolation move, prioritize a clean stretch and squeeze over heavy loading.
What's a good alternative to the dumbbell single arm alternate fly?
A standard two-arm dumbbell fly is the closest variation. You can also use a cable crossover for constant tension or a pec deck machine for a more guided path.
Where should I feel this exercise?
You should feel a stretch across the chest of the working side as you lower the dumbbell, and a contraction in the chest as you bring it back up. Sharp shoulder pain means you're lowering too far or going too heavy.
