Exercise guide · Intermediate · Compound

Dumbbell One Arm Bench Fly: How to Do It & Muscles Worked

The dumbbell one arm bench fly is a unilateral chest exercise that targets the pectoral muscles and also engages the shoulders. It requires balance and control to stabilize the weight with one arm while lying on a bench.

Primary muscles
Chest
Secondary muscles
Shoulders
Equipment
Dumbbell
Level · type
Intermediate · Compound
Demonstration of the dumbbell one arm bench fly
Front view: muscles worked by the dumbbell one arm bench fly. Primary: chest. Secondary: shoulders.
Back view: muscles worked by the dumbbell one arm bench fly. Primary: chest. Secondary: shoulders.
Primary Secondary

How to do the dumbbell one arm bench fly

  1. Step 1: Sit on a flat bench with a dumbbell in one hand, resting it on top of your thigh.
  2. Step 2: Lie back on the bench, keeping the dumbbell pressed against your thigh.
  3. Step 3: Using your free hand, help lift the dumbbell up to the starting position.
  4. Step 4: Hold the dumbbell directly above your shoulder with your arm extended and palm facing inward.
  5. Step 5: Lower the dumbbell out to the side in a wide arc, keeping a slight bend in your elbow.
  6. Step 6: Pause when your arm is parallel to the ground, then reverse the movement and bring the dumbbell back to the starting position.
  7. Step 7: Repeat for the desired number of repetitions, then switch arms and repeat.

Sets, reps and programming

Suggested sets, reps and rest for the dumbbell one arm bench fly by training goal
Goal Sets Reps Rest Effort
Strength 3–5 3–6 3–5 min 1–3 reps in reserve
Muscle growth 3–4 6–12 2–3 min 1–2 reps in reserve
Muscular endurance 2–3 12–20 1–2 min 1–3 reps in reserve

Ranges follow the ACSM position stand on progression in resistance training. Muscle grows across a wide range of loads when sets end close to failure (Schoenfeld et al., 2017), longer rests between heavy sets support strength and size (Schoenfeld et al., 2016), and stopping a rep or two short of failure works about as well as training to failure (Grgic et al., 2022). Estimate your working weights with the strength calculators.

Dumbbell One Arm Bench Fly alternatives

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Sources

  1. American College of Sports Medicine. Progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708.
  2. Schoenfeld BJ, Grgic J, Ogborn D, Krieger JW. Strength and hypertrophy adaptations between low- vs. high-load resistance training. J Strength Cond Res. 2017;31(12):3508-3523.
  3. Schoenfeld BJ, Pope ZK, Benik FM, et al. Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men. J Strength Cond Res. 2016;30(7):1805-1812.
  4. Grgic J, Schoenfeld BJ, Orazem J, Sabol F. Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: a systematic review and meta-analysis. J Sport Health Sci. 2022;11(2):202-211.

Step-by-step instructions and demonstration media are from the ExerciseDB exercise dataset.

This guide is general fitness information, not medical advice. Stop if an exercise causes pain and speak to a doctor or physiotherapist about injuries or health conditions before starting a new programme.