Hammer Curl: How to Perform It.
The hammer curl is the curl done with a neutral grip, palms facing each other: it brings in the brachialis (the muscle hidden under the biceps that pushes the arm "outward") and the brachioradialis of the forearm. It's the secret to thick arms: the biceps make them tall, the hammer makes them wide.
Starting position
- Standing or seated, one dumbbell per hand with a neutral grip, thumbs pointing up.
- Elbows glued to your sides, shoulders down, chest up.
- Wrists straight, in line with the forearm: the "hammer" doesn't bend.
Proper form
- Bend your elbow bringing the dumbbell toward your shoulder, keeping the neutral grip throughout the range.
- The elbow stays planted at your side: if it drifts forward, the movement is over before it's done.
- Rise to the maximum useful flexion, with your thumb pointing at your shoulder.
- Squeeze for a moment at the top.
- Lower over 2-3 seconds until the arm is fully extended.
- Alternate arms or work both simultaneously: what matters is that the torso never enters the movement.
When to inhale, when to exhale
Exhale as you curl up, inhale during the controlled descent. Steady rhythm, no breath-holding.
Mistakes to avoid
As with any curl, using hip momentum to launch the dumbbell steals work from the arm. If you need the swing, the right dumbbell weight is lighter: the brachialis doesn't read the number on the dumbbell.
When the elbow moves forward, the shoulder takes over the movement and tension on the arm drops off at the top. Elbow is the hinge, locked at your side from start to finish.
Bending the wrist inward to "close out" the rep loads the tendons and shortens the useful range. Wrist straight like the handle of a hammer: the exercise is named that for a reason.
The brachialis responds extremely well to eccentric work: the slow lowering phase is where thickness is built. Letting the dumbbell drop cuts the exercise in half.
DAWT tip. The hammer curl holds a few extra kg compared to the classic curl: use that, but don't sacrifice technique for it. A pairing that's always worked: barbell curl first, hammer curl after, when the biceps are already fatigued but the brachialis and forearms still have gas in the tank.
Variations and alternatives
Quick answers
What's the hammer curl for compared to the regular curl?
The neutral grip shifts part of the work from the biceps to the brachialis and brachioradialis: muscles that add thickness to the arm and size to the forearm. It doesn't replace the supinated curl, it complements it.
Better alternating or both arms together?
Simultaneous saves time and keeps the torso more honest; alternating lets you focus on one arm at a time and holds up for a few extra reps. Switch it up over time: these are details, not dogma.
Related exercises
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