Dumbbell · beginner · upper arms
Dumbbell hammer curl
Also called Neutral grip curl, DB hammer curl, Hammer curls, Dumbbell hammer curl.
The hammer curl is a curl done with the palms facing each other instead of facing up. It bends the elbow, so the three elbow flexors do the work: the biceps, the brachialis underneath it, and the brachioradialis in the forearm. The neutral grip reduces how much the biceps can contribute, because turning the palm up is part of what the biceps does and this version never turns it up.
How to do it
- Step oneStand upright holding a dumbbell in each hand with a neutral grip, palms facing your torso.
- Step twoKeep your elbows close to your sides and your upper arms stationary.
- Step threeCurl the dumbbells upward while maintaining the neutral grip, bringing them to shoulder level.
- Step fourPause at the top and squeeze your biceps and forearms.
- Step fiveSlowly lower the dumbbells back to the starting position.
What usually goes wrong
Each starts with what you would notice.
Your torso rocks with every rep and the lift starts from your hips.
WhyMomentum is getting the dumbbells moving, so the arm only has to finish a rep it never started.
FixBegin each rep with the dumbbells hanging still and your torso quiet. If nothing moves without a heave, the weight is wrong for what you are trying to train.
Your palms have quietly turned upward by the time the dumbbells reach the top.
WhyThe forearm is rotating during the curl, which turns this into a standard curl halfway through.
FixWatch the ends of the dumbbells. They should stay pointing forward and back for the whole rep, never rolling to point sideways.
The front of your shoulder is working and your elbows have crept in front of your body.
WhyOnce the elbow travels forward the shoulder starts flexing too, and the front delt joins the lift.
FixKeep the point of the elbow against your ribs from start to finish. Only the forearm should travel.
Your wrists ache and the dumbbells feel like they are tipping out of your hands.
WhyThe wrist is folding backward under the load rather than staying in line with the forearm.
FixHold the hand straight, so the forearm and the dumbbell make one line. If the wrist keeps collapsing, the dumbbell is heavier than the grip can hold level.
Hammer curl or regular curl
The usual story is that the regular curl is for the biceps and the hammer curl is for the muscles underneath and beside it. Half of that is right and half is not, and it is worth getting straight because it changes why you would pick one.
The right half: palms up is where the biceps contributes most, because turning the forearm palm up is one of the two jobs the biceps does. Take that away with a neutral grip and the biceps has less reason to work as hard.
The part that does not hold: the brachialis, the muscle sitting under the biceps, attaches to the forearm bone that does not rotate. It has no way of knowing which direction your hand faces. It works just as hard in a normal curl. And when ten competitive bodybuilders curled all three grips head to head, the forearm muscle everyone credits the hammer curl with was actually slightly more active with the palms up, not with the palms neutral. That is one small study in a narrow group and the differences were small, so treat it as a reason to stop repeating the claim rather than a reason to reverse it.
The real case for hammer curls is simpler and it survives all of this. The neutral grip is kinder on wrists that hurt with palms up, the dumbbell sits in the hand more securely, and most people can handle a heavier one. That is enough reason to do them.
Straight up or across the body
The cross-body version curls each dumbbell toward the opposite shoulder rather than straight up the front of the thigh.
It is claimed to shift the work further onto the muscle underneath the biceps, on the grounds that the upper arm sits differently. Nobody has shown a difference, and the coaching sources that recommend it usually admit as much.
Pick whichever gives you a clearer path for the dumbbell. If your forearms are wide enough that a straight-up curl bangs the dumbbell into your hip, the cross-body version fixes a real problem, which is a better reason than the muscle argument.
No muscle answers only to a neutral grip
This movement is sold almost entirely on arm thickness. We are not going to tell you what your arms will look like, and neither should anybody else.
What is fair to say is narrower. The hammer curl trains the same three elbow flexors as any other curl, in a grip that most people find steadier and less awkward on the wrist. It does not switch a different muscle on. There is no muscle that only a neutral grip reaches.
It also does nothing for the back of the arm. If you are curling because you want your arms to do more, the triceps is the larger muscle up there and no curl touches it.
What it is for
The dumbbell hammer curl is an upper arm exercise targeting the biceps with a neutral grip. This grip variation places greater emphasis on the brachialis and brachioradialis muscles, contributing to overall arm thickness and strength.
Questions people ask
- What muscles does the hammer curl work?
- The same three that bend the elbow in any curl. The biceps, the brachialis underneath it, and the brachioradialis in the forearm. The neutral grip lowers how much the biceps can give, because turning the palm up is part of its job and this version never does.
- Is the hammer curl better than a regular curl?
- Not better, different in a smaller way than usually claimed. Palms up is where the biceps contributes most. The muscle under the biceps has no anatomical reason to care which way your hand faces, and the grip study that measured the other two flexors could not record it either way. The genuine advantage of the hammer curl is comfort: it is easier on the wrists and the dumbbell sits more securely, so many people can handle a bit more weight.
- Do hammer curls work your forearms?
- Your forearms work, but so do they in every curl. The one study that compared palms up, palms neutral and palms down head to head found slightly more forearm muscle activity with the palms up, in ten competitive bodybuilders. It was a small study with small differences, so the safe reading is that the grip does not change the target much either way.
- Should the dumbbells touch your shoulders at the top?
- They do not need to. Curl until the forearm has run out of travel with the elbow still against your ribs. If you have to shove the elbow forward to get the dumbbell higher, you have stopped curling and started raising.
- Can you do hammer curls if your wrists hurt on regular curls?
- It is the usual reason people switch. The neutral grip does not ask the forearm to turn palm up under load, which is the position some wrists object to. If something hurts and keeps hurting, that is a question for a physiotherapist.
- How heavy should hammer curls be?
- Heavy enough that the last reps are hard, light enough to start every rep from a dead hang with your body still and your wrists straight. Most people can hammer curl a slightly larger dumbbell than they can curl palms up, and that is normal rather than a sign of anything.