Single Arm Kettlebell Flye — how to, muscles worked, alternatives

How to do the Single Arm Kettlebell Flye

Lie on a bench, feet flat, kettlebell over your chest in one hand.
Keep a slight bend in your elbow, free hand on your stomach.
Slowly lower the kettlebell out to the side in a wide arc.
Bring it back up, squeezing your chest as you finish.
Finish reps, then switch sides.

Full technique — 7 steps

Lie on a flat bench with feet planted and a kettlebell held above your chest in one hand.
Rest your free hand on your stomach and keep a slight, fixed bend in your working elbow.
Set your shoulder blades down into the bench and hold the kettlebell over your chest.
Lower the kettlebell out to your side in a wide arc without changing your elbow angle.
Descend until your chest is fully stretched and your upper arm reaches bench level or slightly below.
Bring the kettlebell back along the same arc by drawing your upper arm inward.
Finish with the kettlebell above your chest, then complete all reps before switching sides.

Common mistakes

Turning the flye into a press
Bending and straightening the elbows
Dropping too deep at bottom
Letting shoulders roll forward
Twisting the torso toward the kettlebell

Form cues

Slight elbow bend, fixed angle
Stretch, don't force depth
Match the same arc
Keep shoulders down and back
Keep hips level

Substitutes by equipment

Same muscles, same movement — pick the version you have the gear for.

Where to start and where to go next

Same muscles, same movement. Too hard for now — step down; once it gets easy — step up.

Easier Dumbbell Floor Flye Beginner
Easier Dumbbell Flye Beginner
This exercise Single Arm Kettlebell Flye Intermediate
Harder Suspension Trainer Chest Fly 80% of bodyweight

Too hard for now? Start with the Dumbbell Flye.

Quick answers

What muscles does the Single Arm Kettlebell Flye work?

Primary: Mid chest 9/10. Also works: Front delts 5/10, Biceps 3/10, Forearms 4/10, Rotator Cuff 3/10.

When should I do the Single Arm Kettlebell Flye in a workout?

Finisher. Goes last, once the heavy work is done. ≈ 8 min with rest.

How many sets and reps of the Single Arm Kettlebell Flye?

Strength: 3 sets of 8–10 reps, rest 1 min 30 s, 3 reps in reserve. Muscle growth: 3–4 sets of 10–12 reps, rest 1 min, 2–3 reps in reserve. Endurance: 2–3 sets of 15–20 reps, rest 45 s, 3–4 reps in reserve.

What can I do instead of the Single Arm Kettlebell Flye?

Resistance bands: Resistance Band Chest Fly, Single Arm Resistance Band Chest Flye. Cable machine: Lying Cable Flye, Mid Cable Flye. Dumbbells: Single Arm Dumbbell Floor Flye, Stability Ball Dumbbell Flye. Weight plates: Lying Svend Press.