Hammer Curls
Hammer curls have you curl a pair of dumbbells with your palms facing each other the entire rep, like gripping a hammer. That neutral grip shifts some of the work from the biceps toward the brachialis and forearms, making the exercise a good complement to a standard curl for arm size and forearm strength, and it suits lifters at any level since it needs nothing more than a pair of dumbbells.
Why it works
Keeping your palms neutral throughout the curl changes which muscles do the heaviest lifting compared to a standard supinated curl. The brachialis, a muscle that sits underneath the biceps, gets more direct involvement in this grip, and the brachioradialis in your forearm has to work harder to stabilize the weight. Building those muscles alongside the biceps adds size to the upper arm from a different angle and improves your grip and forearm strength for pulling movements elsewhere in your training.
Set up
- Stand with a dumbbell in each hand, palms facing your body.
- Set your feet shoulder-width apart with a slight bend in your knees.
- Pin your elbows to your sides before the first rep.
- Keep your shoulders back and your core braced.
How to do it
- Curl one or both dumbbells up while keeping your palms facing each other.
- Squeeze at the top of the movement without letting your elbow drift forward.
- Lower the dumbbell under control back to the starting position.
- Keep your upper arm still throughout the entire rep.
- Repeat for the set, alternating arms or curling both together depending on your goal.
Form cues
- Palms stay facing each other the whole rep.
- Elbows stay pinned to your sides.
- Lower the weight slowly, don't let it drop.
- No swinging the torso to help the weight up.
Breathing: Exhale as you curl the dumbbell up, then inhale as you lower it back down under control.
Common mistakes
Swinging the torso backward to generate momentum for the curl.
Fix: Drop the weight if you can't curl it without rocking your body; the movement should come from your elbow only.
Letting the elbow drift forward and away from the torso as the arm fatigues.
Fix: Keep your upper arm pinned against your side for the entire set, even if that means slowing down or reducing reps late in the set.
Dropping the weight quickly on the way down instead of controlling the lowering phase.
Fix: Take at least two seconds to lower the dumbbell each rep; the eccentric portion builds as much of the muscle as the lift itself.
Turning the wrist to face upward partway through the rep, drifting into a standard curl.
Fix: Watch your thumb position; it should stay pointed roughly forward or upward the entire rep so your grip never rotates into a supinated curl.
How to program it
- As a single-joint arm exercise, 3 sets of 10 to 15 reps twice a week is a solid default, since the movement recovers quickly compared to compound pulling lifts.
- Place it after your main back or pulling exercises for the session, since it works well as accessory volume rather than a primary lift.
- Alternating arms one at a time lets you focus on form longer per rep; curling both together saves time when your session is tight.
- If your forearms fatigue before your biceps do, that's a sign the neutral grip is shifting real work onto the brachioradialis; drop the weight slightly rather than letting grip failure cut biceps sets short.
Safety notes
- Choose a weight you can lower under control; letting the arm snap straight at the bottom puts unnecessary strain on the elbow.
- Stop the set if you feel sharp pain in the elbow or wrist rather than working through it.
- Warm up the wrists and forearms with a few light reps before your working sets, since the neutral grip puts more direct load on those joints than a standard curl.
- If you're recovering from a wrist or elbow issue, check with a physical therapist before loading this pattern heavily; the fixed neutral grip changes the joint angles compared to other curls.
Exercise profile
- Force
- Pull
- Mechanics
- Isolation
- Category
- Strength
Frequently asked questions
How many sets and reps should I do for hammer curls?
Three sets of 10 to 15 reps, done once or twice a week, builds solid biceps, brachialis, and forearm size for most people.
Can I do hammer curls without dumbbells?
A resistance band with a neutral-grip handle, or a cable with a rope attachment, both let you train the same neutral-grip curl pattern at home.
Hammer curls vs regular curls, what's the difference?
Regular curls use a palms-up grip that emphasizes the biceps more directly. Hammer curls use a neutral, palms-facing grip that shifts more work to the brachialis and forearms, so most lifters include both for complete arm development.
Why don't I feel hammer curls in my biceps as much as regular curls?
That's expected. The neutral grip shifts emphasis toward the brachialis and forearm rather than the biceps, so a lighter biceps sensation with more forearm fatigue is a normal difference between the two exercises, not a sign you're doing it wrong.