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Hammer Curl

The hammer curl is a dumbbell curl performed with the palms facing each other, shifting work onto the brachioradialis and brachialis alongside the biceps. It builds the forearm and elbow strength that carries over to pull-ups, rows and everyday grip. Coached by Maddy (NASM-CPT) — these are the exact form cues he gives on every client's first week.

Muscles worked

Forearms · brachioradialis Biceps · biceps brachii Brachialis Forearm flexors

Sets & reps by goal

Goal	Sets × Reps	Rest
Strength	4 sets × 4-6 reps	2 min
Muscle	3-4 sets × 9-12 reps	60-90 sec
Endurance	2-3 sets × 18-27 reps	30-45 sec

Rep ranges per Helms 2014 · Schoenfeld 2016.

Level — Beginner

Beginner — one of the safest loaded arm exercises; tempo discipline is the entire art.

Proper form — 5 cues

Hold the dumbbells like hammers — thumbs up, palms facing your body.
Pin the elbows to the sides; they drift neither forward nor backward.
Curl until the thumb points at the front of the shoulder.
Lower on a three-count until the arms hang completely straight.
Lock the wrists in neutral — no flicking the weight up at the top.

Breathing: Exhale as the dumbbells curl up, inhale on the slow lowering.

The 3 mistakes Maddy corrects most

Swinging the torso to start each rep. The hip-and-back kick moves the dumbbell but bypasses the elbow flexors the curl is for. Fix: Stand with the shoulder blades against a wall for a set — the wall confiscates the swing.

Elbows creeping forward as the weight rises. Forward drift hands the top of the rep to the front delts and shortens the working range of the arms. Fix: Imagine the elbows are bolted to your ribs, and end the set when they break loose.

Dropping the dumbbells through the lowering phase. The eccentric half is where much of the growth stimulus lives; letting gravity take it wastes half the set. Fix: Match every lift with a slower, fully straightened descent.

Common questions

Hammer curls vs regular curls — what changes with the grip?

The neutral grip puts the brachioradialis — the big forearm muscle — and the brachialis underneath the biceps into stronger positions, while the biceps itself works at a slight mechanical disadvantage. Practically: hammer curls usually let you lift a bit more, thicken the forearm and elbow region, and complement rather than replace supinated curls.

Why can I hammer curl more than I can regular curl?

With the thumbs up, the strongest elbow flexors line up to pull together, and the wrist sits in its most stable position. The few extra kilos are a mechanical gift, not proof of stronger biceps — so resist loading hammer curls so heavy that the strict tempo disappears.

Should I do hammer curls seated or standing?

Standing is the default and trains a touch of trunk control; seated on an upright bench removes the temptation to swing and is the stricter choice when the weights get challenging. Alternating arms also works — it lets you spot form drift in a mirror one arm at a time. All variants respect the same rule: elbows pinned.

Related exercises

Alternate Hammer CurlForearms · Biceps Seated Hammer CurlForearms · Biceps Alternate Biceps CurlsBiceps Biceps CurlsBiceps Rope Hammer CurlForearms · Biceps

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