- Target muscle: Sternal (Lower) Pectoralis Major
- Synergists: Clavicular (Upper) Pectoralis Major, Anterior Deltoid, Triceps Brachii
- Dynamic stabilizer: Biceps Brachii (short head only)
- Mechanics: Compound
- Force: Push
- Holding a dumbbell in one hand, sit on a flat bench and rest the dumbbell on your knee.
- Kick the dumbbell up with your knee as you lie supine (on your back) on the bench.
- Position the dumbbell next to the side of your chest and hold it using a neutral or hammer grip (palm facing inward). Your wrist should be directly under your elbow, and your elbow should be flexed and tucked into your body a little.
- Spread your feet and grasp the bench with your free hand for support.
- Exhale as you press the dumbbell upward and inward in an arcing motion until your arm is fully extended over your chest.
- Inhale as you reverse the movement and lower the dumbbell to the starting position.
- Repeat for the prescribed number of repetitions.
- After you have finished, bring the dumbbell gently down onto your knee and sit up.
- Repeat the exercise with your opposite arm.
Comments and tips
- Unilateral (single-sided) exercises such as the one-arm hammer-grip dumbbell bench press are important for developing unilateral strength, balance and coordination. By putting your body out of balance, they also force the recruitment of more stabilizer muscles, especially in your core.
- Keeping your elbow tucked into your body a little and using a neutral grip make the one-arm hammer-grip dumbbell bench press safer on your shoulder joint.
- See also the hammer-grip dumbbell bench press and the incline one-arm dumbbell bench press.
One-arm hammer-grip dumbbell bench press video
This is the closest video demonstration I could find to the one-arm hammer-grip dumbbell bench press. The form is decent, but he’s using more of a pronated grip than a hammer grip. I would also very strongly recommend against switching hands while the dumbbell is over your body.