The hammer curl is a dumbbell curl variation performed with a neutral grip, palms facing each other throughout the movement. This grip shifts emphasis onto the brachialis and brachioradialis, muscles that add thickness to the arm and width to the forearm. It is a beginner-friendly, joint-comfortable exercise that complements traditional curls for complete arm development.
Muscles Targeted
- Primary: Brachialis, brachioradialis
- Secondary: Biceps brachii (especially the long head)
- Tertiary: Forearm flexors and extensors, anterior deltoid
Starting Position
Stand tall with feet shoulder-width apart, holding a dumbbell in each hand at your sides with a neutral grip (palms facing your thighs). Keep your elbows tucked close to your torso, shoulders back, chest up, and a slight bend in your knees. Engage your core and maintain a neutral spine before beginning the curl.
Execution Steps
- Keep your elbows pinned to your sides as a fixed pivot point throughout the movement
- Curl the dumbbells up by flexing at the elbows while maintaining the neutral, palms-facing grip
- Raise the weights toward your shoulders without letting your upper arms drift forward
- Squeeze at the top where you feel the strongest contraction in the upper arm
- Lower with control back to the starting position, resisting the weight on the way down
- Repeat for the desired reps, keeping the grip neutral and the elbows stationary
Form Cues
- Keep the grip neutral: Maintain palms-facing-each-other throughout—never rotate the wrists
- Pin the elbows: Keep your upper arms locked against your sides so the elbow stays the only moving joint
- Control the negative: Lower slowly rather than dropping the weights to maximize tension
- Stay upright: Avoid leaning back or swinging the torso to hoist the weight
- Full range of motion: Extend fully at the bottom and curl high at the top for complete development
Common Mistakes
- Swinging the body: Using momentum to heave the dumbbells reduces tension on the target muscles.
- Letting elbows drift forward: Allowing the upper arms to move forward turns the curl into a partial front raise.
- Using too much weight: Overloading forces poor form and momentum-based reps. Choose a controllable weight.
- Incomplete range of motion: Cutting reps short at the bottom or top limits muscle growth.
- Rotating the wrists: Turning the palms up mid-rep converts the movement into a standard curl and removes brachialis emphasis.
Variations
- Alternating hammer curl: Curling one arm at a time for greater focus and control
- Seated hammer curl: Removes lower-body momentum for stricter execution
- Cross-body hammer curl: Curling across the torso to further target the brachialis
- Cable rope hammer curl: Constant-tension version using a rope attachment
- Incline hammer curl: Performed on an incline bench for an increased stretch
Tips for Progression
- Increase weight gradually: Add 2.5-5 pounds per dumbbell once you complete all reps with strict form
- Increase reps: Build to 12-15 controlled reps before adding load
- Add a pause: Hold the top contraction for 1-2 seconds to increase intensity
- Slow the tempo: Lengthen the lowering phase to increase time under tension
Training Notes
Include hammer curls in your arm or pull-day training 1-2 times per week, often paired with supinating curls for balanced arm development. They work best for 8-15 reps with moderate weight and a controlled tempo. Rest 45-90 seconds between sets. Because they emphasize the brachialis and brachioradialis, hammer curls are especially valuable for adding arm thickness and building grip and forearm strength that carries over to pulling movements.