Exercise guide
Dumbbell One Arm Floor Fly
- Intermediate
- Isolation
- Rep-based
- Chest
- Shoulders
This unilateral isolation exercise targets the chest and front deltoids while using the floor as a safety depth-stop to prevent shoulder strain. It allows for focused muscle activation on one side at a time, helping to correct strength imbalances.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Lie flat on your back on the floor with your knees bent and feet flat for stability.
- Hold a dumbbell in one hand directly over your chest with a neutral grip (palm facing inward).
- Extend your opposite arm out to the side or place it on your hip to help maintain balance.
- Retract your shoulder blades and press them firmly into the floor.
How to do it
- Inhale and slowly lower the dumbbell in a wide arc out to your side until your upper arm lightly brushes the floor.
- Keep a slight, fixed bend in your elbow throughout the descent to protect the joint.
- Exhale and contract your chest to pull the dumbbell back to the starting position in the same wide arc.
- Maintain a controlled tempo, taking 2-3 seconds to lower the weight and 1 second to return to the top.
Form checklist
- Keep your lower back pressed into the floor to avoid arching.
- Ensure the movement occurs only at the shoulder joint, not the elbow.
- Do not let the weight rest on the floor; tap lightly and immediately begin the ascent.
- Keep your working shoulder blade pinned down to maximize pectoral engagement.
Pro tips
- Focus on bringing your inner bicep toward your sternum at the top of the movement for a peak pectoral contraction.
- Stop the dumbbell just before it is directly over your shoulder to keep constant tension on the chest.
Make it harder
- Add a 2-second isometric hold at the bottom of the range, hovering an inch above the floor.
- Lift your legs into a tabletop position (90-degree bend) to increase the stability challenge for your core.
Frequently asked
- What muscles does the dumbbell one arm floor fly work?
- The dumbbell one arm floor fly primarily targets the pectorals, and also works the abs and serratus anterior as secondary muscles.
- What equipment do you need for the dumbbell one arm floor fly?
- The dumbbell one arm floor fly uses dumbbell.
- Is the dumbbell one arm floor fly good for beginners?
- The dumbbell one arm floor fly is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.