Hammer Curls
A standing curl with the palms facing each other throughout, thumbs on top. The neutral grip hands the work to the brachialis and brachioradialis instead of asking the biceps for supination, which is why almost everyone can hammer curl more weight than they can curl with palms up.
Own the movement
Set up first, then execute. Every cue below is something you can check on your next set.
Before the first rep
- Stand tall with feet hip-width, dumbbells hanging at arm's length beside your thighs, palms turned in toward your legs.
- Tuck both elbows against your ribs and keep them there — they are a hinge, not a lever.
- Squeeze your glutes and brace lightly so your lower back cannot arch to help.
- Grip the handle firmly and keep the wrist straight, knuckles in line with the forearm.
Every rep
Breathing & tempo — Exhale on the way up, inhale on the way down; no breath holding on an isolation lift this small. One second up, one second held, three seconds down.
Sets, reps & load
Where to start, and what to change when it stops being hard.
Expect to handle 10-20% more than your palms-up dumbbell curl. Start at 10-14 kg per hand if you have been training a year, 5-8 kg if you are new. Add 2 kg per hand once you hit the top of your rep range on every set with no torso sway — reps stall long before the elbows do, so use weight as the driver here.
What goes wrong
The errors that show up most often, and the cue that fixes each one.
Stand with your back and heels a few centimetres from a wall. If your shoulders or hips touch it mid-set, the weight is too heavy — drop 4 kg per hand.
Point both thumbs at the ceiling on every rep and check the last two reps of a set, which is where the rotation creeps in.
Pause for a beat with arms fully straight before each rep. Reset the count if you catch yourself bouncing.
Keep the elbow behind the wrist for the whole ascent and stop the rep when the forearm reaches vertical, not when the dumbbell touches your shoulder.
Why bother
The brachialis sits underneath the biceps and attaches to the ulna, so it bends the elbow regardless of where your palm points. A neutral grip removes the biceps' supination advantage and shifts the load onto that muscle plus the brachioradialis in the forearm. Grow the brachialis and it pushes the biceps up from beneath — that is where the visible height of a flexed arm comes from.
The neutral wrist is also the strongest and most forgiving position at the elbow. Lifters whose wrists or elbows complain during palms-up barbell curls can usually hammer curl pain-free at heavier loads, which makes this the default curl for anyone with cranky joints from pressing volume.
Where it fits
Run it as your main arm movement or straight after a supinated curl on an upper-body or pull day. Because the elbow flexors also work in every row and chin-up, 6-10 hard curl sets a week across two sessions is enough for most people; more usually just delays the elbows recovering.
If this one isn't it
No kit, too hard, or too easy — here's where to go instead.
Same job, different kit
Start here instead
Asked and answered
Do hammer curls build the biceps or the forearms?
Both, and neither exclusively. The main beneficiaries are the brachialis, which lies under the biceps, and the brachioradialis in the upper forearm. The biceps still works — it flexes the elbow in any grip — it just loses the supination contribution. If you want direct biceps peak work, pair these with a supinated curl rather than replacing it.
Why can I hammer curl more than I can regular curl?
Because the brachialis is a pure elbow flexor with a good mechanical line, and the neutral grip puts the wrist in its strongest position. You also lose no force to holding supination. A 10-20% gap between the two is normal and not a sign of anything being weak.
Should I alternate arms or curl both at once?
Both together is more time-efficient and stops you swinging the torso in a rhythm. Alternating lets you use a bit more weight per arm and hold a longer squeeze. Pick one and keep it consistent within a training block so the logged numbers mean something.
Are hammer curls better than barbell curls for elbow pain?
Usually, yes. A fixed supinated barbell grip locks the forearm in rotation and stresses the medial elbow; dumbbells in neutral let each arm find its own line. If pressing volume has your elbows sore, hammer curls are the variation to keep and the straight-bar curl is the one to drop.