How to do the hammer curl

The hammer curl is the curl to add when you want thicker arms and stronger forearms, and it's the one we'd reach for first if regular curls bother your elbows. Keeping your palms facing each other shifts more of the work onto the brachialis, a muscle that sits underneath the biceps, and onto the thick forearm muscle on the thumb side of your arm. Most people can also handle a bit more weight than on a standard dumbbell curl, because that palms-in position is a stronger one for the elbow.

How to do a hammer curl

1. Stand with a dumbbell in each hand, palms facing your thighs. Feet about hip width apart, arms straight at your sides, thumbs pointing forward.
2. Set your elbows and brace. Tuck your elbows against your sides, pull your shoulders back slightly and tighten your abs so nothing but your forearms will move.
3. Curl the dumbbells up with your thumbs leading. Your palms keep facing each other the whole way, like you're lifting a pair of hammers to look at the heads.
4. Stop when the dumbbells reach the front of your shoulders. Your forearms are close to vertical and your elbows are still by your sides. Squeeze for a second.
5. Lower over two or three seconds. Keep your palms facing in and go all the way down until your arms are straight.

You can curl both arms together or alternate. Alternating makes it easier to keep strict form, especially as the weight gets heavier.

You'll feel it on the outside of your upper arm and the top of your forearm, near the elbow, more than in the peak of the biceps. That's normal and it's the point. A deep ache on the inside of the elbow isn't normal; drop the weight and slow down.

Cues that help mid-set

"Thumbs to your shoulders." Aim the top of your fist at the front of your shoulder. It keeps your wrists in the neutral position and the dumbbells on a straight path.

"Squeeze the handles hard." A firm grip gets your forearms working more and makes the dumbbells feel steadier. It's one of the few exercises where gripping harder genuinely helps.

"Elbows by your pockets." If your elbows swing forward at the top, your shoulders are helping. Keep them tucked and stop the rep a little lower if you need to.

Common mistakes

Swinging the body. The knees dip, the hips drive forward and the dumbbells swing up. This happens more on hammer curls than on other curls, because people load them heavier. Take the weight down until you can curl with your body completely still, and start every rep from straight arms.

Rotating the wrists during the curl. The palms start facing each other and then turn up (which makes it a regular dumbbell curl) or turn down toward the floor. Both change which muscles do the work. Keep the dumbbell handles pointing straight forward from bottom to top. If you find your wrists turning without meaning to, think about keeping your thumbs pointed at the ceiling at the top.

Using too heavy a weight. Hammer curls feel stronger than regular curls, so it's tempting to grab the heaviest dumbbells you can hold and heave them up with half reps. Your arms get more out of full reps with a weight you control than half reps with one you don't. Pick a weight you can take from straight arms to your shoulders without any swing, for at least 8 reps.

Cutting the range short. Stopping halfway up, or starting each rep with your elbows still bent, lets you move more weight and skips the stretched bottom part of the curl. Go all the way down and all the way up.

Sets, reps and how much weight to use

For most people, 3 sets of 8 to 15 reps works well. Use a weight you could still curl 1 or 2 more times with good form, and rest 60 to 90 seconds between sets. Beginners usually start with 10 to 20 lb (5 to 9 kg) dumbbells per hand.

Hammer curls usually go after your main curl in a session, or at the end of a back day. If you only have room for one curl in your program, we'd still pick a regular dumbbell or barbell curl, because turning the palm up is part of what the biceps do and hammer curls don't train it. Hammer curls are the better choice as the only curl when your elbows don't tolerate the palms-up position.

Progress by adding reps first, then move up to the next pair of dumbbells when you hit the top of your rep range on every set. The jumps are big (15 lb to 20 lb is 33% more weight), so expect to lose a few reps when you move up. Our progressive overload guide covers other ways to keep progressing.

Here's roughly what people use for their normal working sets, per dumbbell:

Hammer Curl working weights by bodyweight and experience, per dumbbell

Bodyweight	beginner	intermediate	advanced
130 lb (59 kg)	10 lb (5 kg)	20 lb (9 kg)	30 lb (14 kg)
160 lb (73 kg)	15 lb (7 kg)	25 lb (11 kg)	35 lb (16 kg)
190 lb (86 kg)	15 lb (7 kg)	30 lb (14 kg)	40 lb (18 kg)
220 lb (100 kg)	20 lb (9 kg)	35 lb (16 kg)	50 lb (23 kg)
250 lb (113 kg)	20 lb (9 kg)	40 lb (18 kg)	55 lb (25 kg)

One honest caveat: the "hammer curls build the brachialis, regular curls build the biceps" split is tidier in theory than in your arm. The biceps still work hard during a hammer curl, and the brachialis works during every curl. The grip shifts the balance a bit; it doesn't switch muscles on and off.

Variations and alternatives

• Cross-body hammer curl: curl each dumbbell across your body toward the opposite shoulder. Some people find it more comfortable on the elbows, and it's easier to keep the upper arm still.
• Seated hammer curl: the same exercise sitting on a bench. Useful if you catch yourself swinging when standing.
• Rope cable hammer curl: a rope on a low pulley, palms facing in. The cable keeps tension on your arms at the bottom of each rep, and small weight jumps make progress easier.
• Reverse curl: palms facing down, with a barbell or EZ bar. It works the forearms even harder, though you'll need much less weight.
• Dumbbell curl and barbell curl: the palms-up versions. Do one of them alongside hammer curls to cover both jobs the biceps do.

Hammer curl questions

Are hammer curls better than regular curls?

They're different, not better. Regular curls work the biceps more; hammer curls work the brachialis and forearms more. Doing both across your week is the simplest way to cover everything.

Do hammer curls build forearms?

Yes, especially the muscle on the thumb side of your forearm, near the elbow. For forearms that also look thicker near the wrist, add reverse curls or grip work.

Why can I lift more on hammer curls?

The neutral grip puts your elbow in a mechanically stronger position and lets the brachialis and forearm muscles contribute more. Most people use about 10 to 20% more weight than on a regular dumbbell curl.

My elbow hurts when I curl. Should I switch to hammer curls?

It's worth trying, since many people with sore elbows find the neutral grip more comfortable. Go lighter than usual for a couple of weeks. If the pain doesn't settle, get it looked at by a physical therapist rather than pushing through.