Biceps variation that develops the brachialis muscle and forearms

Hammer curls are a biceps curl variation in which the palms are held neutral — facing each other, as if holding a hammer. This position places greater emphasis on the brachialis muscle (located beneath the biceps) and the forearm muscles. The result is thicker, more massive arms.
Stand upright, dumbbells in hands at your sides, palms facing each other (neutral grip).
Elbows tucked to your sides — they do not move throughout the exercise.
Tighten your abs, chest lifted, shoulders back.
Curl the dumbbells toward your shoulders while maintaining a neutral grip throughout the movement.
At the top, briefly squeeze — no wrist rotation.
Slowly lower the dumbbells back down — control the negative phase.
| Muscle | Activation Level |
|---|---|
| Brachialis muscle (brachialis) | ★★★★★ |
| Biceps brachii muscle (biceps brachii) | ★★★★☆ |
| Forearm flexor muscles (forearm flexors) | ★★★★☆ |
| Abductor pollicis longus (brachioradialis) | ★★★☆☆ |
✅ Keep your torso stable — if you need to swing, the weight is too heavy.
✅ Palms should remain facing each other throughout the exercise — this is not a biceps curl.
✅ Slow, controlled movement — 2 sec up, 3 sec down.
✅ Elbows should remain tucked to your sides — do not let them move.
| Variation | Description |
|---|---|
| Easier Seated hammer curl | The seated position eliminates the possibility of body swinging. |
| Easier Alternating hammer curl | One arm at a time — more focus on each repetition. |
| Harder Cable rope hammer curl | With a cable rope — constant tension throughout the range of motion. |
| Harder Concentration hammer curl | Elbow resting on the thigh — maximum isolation. |
Hammer curl works the biceps and brachialis with a neutral grip:
How is it different from a regular curl? A neutral grip (palms facing your body) engages the brachialis more and puts less strain on the wrist.
Dumbbells or barbell? Dumbbells make it easier to maintain a neutral grip and work both arms equally.
Can it be done seated? Yes, but standing makes it easier to keep your elbows at your sides.