Hammer curl
The hammer curl is a dumbbell curl with the palms facing each other the whole way up. That one change moves part of the work from the biceps to the muscles under it and along the forearm, and most people can use a little more weight than on a regular curl. It is also one of the easiest lifts to cheat, because a small swing from the hips feels like strength.
Updated September 2026
- Equipment
- Dumbbell
- Primary
- Biceps
- Secondary
- —
- Level
- Beginner
How to do it
- Stand up with your torso upright and a dumbbell on each hand being held at arms length. The elbows should be close to the torso.
- The palms of the hands should be facing your torso. This will be your starting position.
- Now, while holding your upper arm stationary, exhale and curl the weight forward while contracting the biceps. Continue to raise the weight until the biceps are fully contracted and the dumbbell is at shoulder level. Hold the contracted position for a brief moment as you squeeze the biceps. Tip: Focus on keeping the elbow stationary and only moving your forearm.
- After the brief pause, inhale and slowly begin the lower the dumbbells back down to the starting position.
- Repeat for the recommended amount of repetitions.
Instructions from free-exercise-db, public domain — the same text the app shows on this exercise.
Saying it out loud
Any of these logs a set of hammer curl in SayLift. Say the whole session in one go if you want — weights, reps and sets in whatever order they come out.
- “Hammer curls, three sets of twelve at 30”
- “Hammer curls 35 for 10, 10 and 8”
- “Hammer curls 25 pounds, four sets of 12”
- “Hammer curls, 30 for 12, then 35 for 8 and 8”
What the thumbs-up grip changes
With the thumbs pointing up, the biceps curls from a weaker position. The brachialis (the muscle under the biceps) and the brachioradialis (the thick muscle on top of the forearm) pick up more of the load. That is why hammer curls add thickness to the upper arm and forearm, while a palms-up curl leaves more of the job to the biceps.
Most programmes use both. A common order is a palms-up curl first, while you are fresh, and hammer curls after it.
SayLift logs your whole workout from one spoken sentence. iPhone only, 873 exercises built in, 3 days free then $49.99 a year.
Start the free trialThe swing is the mistake that matters
If the dumbbells start moving because your hips moved first, momentum is lifting them. This happens on the last two reps of a set, which are also the reps you most want to count. A rep you had to throw up is a rep your biceps did not do.
Stand with your back against a wall or a post for a few sets if the swing keeps coming back. It removes the option.
- Elbows stay by your sides. If they drift forward, the front of the shoulder joins in.
- Stop at shoulder height. Curling higher only gives the arm a rest at the top.
- Lower for about two seconds. Dropping the weight skips half of every rep.
- Alternating or both at once are both fine. Pick one and stay with it, because they are logged as different exercises.
Logging a lift with big weight jumps
Dumbbells usually go up in 5 lb steps, and on a curl that is a lot. Going from 25s to 30s is a 20 percent increase, which few people can make in one week. So progress shows up in reps first: 25 for 10, 10 and 9 becomes 25 for 12, 11 and 10 before the 30s come off the rack.
That only works if every set is written down, including the last one that fell short. Saying it takes a few seconds. In SayLift you say "hammer curls, 25 for 12, 11 and 10" and the AI coach reads those reps when it sets your next working weight.
Frequently asked questions
Hammer curls vs bicep curls: which is better?
They share most of the work. The hammer grip puts more of it on the brachialis and the forearm, and the palms-up curl keeps more on the biceps itself. If you only have time for one, do the one you can keep strict, and add the other when you can.
What muscles do hammer curls work?
The biceps, plus the brachialis underneath it and the brachioradialis along the top of the forearm. Those two work harder when the thumbs point up.
Should I alternate arms on hammer curls?
Either way works. Alternating gives each arm a short rest and makes it easier to stay strict. Curling both at once saves time. Keep them as separate exercises in your log so each history compares like with like.
Stop typing between sets
Say what you lifted. SayLift writes down every set, rep and weight, then tells you what to lift next time. iPhone only, 3 days free then $49.99 a year.
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