Seated Hammer Curl – Muscles Worked, How-To, Benefits, and Alternatives

If you want stronger, more muscular arms, curls are a must.

Yes, chin-ups, dips, and other compound exercises ARE great arm builders, but they work your arms indirectly. Ask any bodybuilder about the best way to sculpt massive biceps and triceps, and they’ll be only too happy to tell you that you need direct arm exercises, too. Presses and rows are not enough.

So, most lifters include plenty of barbell and dumbbell curls in their workouts, usually with a supinated or palms-up grip.

However, as effective as these exercises are, there are others that are just as useful for building your arms.

In this article, we explain how to use seated hammer curls to build not just massive biceps but huge forearms, too.

Seated Hammer Curl – Muscles Worked

Seated hammer curls are an isolation exercise, which means they involve movement at just one joint. But, despite being such a simple movement, seated hammer curls work a several very important muscle groups.

The muscles trained during seated hammer curls are:

Biceps brachii – usually just called the biceps for short, this is the most prominent anterior upper arm muscle. The biceps have three functions: flexion of your elbow, supination of the forearm, and flexion of the shoulder joint. Biceps brachii means two-headed arm muscle.

Brachioradialis – located on the thumb-side of the upper forearm, the brachioradialis works with the biceps to flex the elbow. It’s technically a forearm muscle but is strongly involved in the seated hammer curls. Well-developed brachioradialis muscles link your upper arm to your lower arm and adds thickness to your forearm.

Brachialis – located beneath your biceps, the small but powerful brachialis muscle is your strongest elbow flexor. It works with your biceps to bend your elbow joint. As well as being very strong, this muscle helps to “prop up” your biceps and makes it look bigger. Hammer curls place a lot of tension on this important muscle.

Forearms – there are lots of muscles that make up the forearms. The flexor group bends your wrist while the extensors straighten it. Both sets of muscles are involved in hammer curls, making this exercise good for building your upper and lower arms.

How to Do Seated Hammer Curls

Get more from seated hammer curls while keeping your risk of injury to a minimum by following these guidelines:

1. Set the backrest on an exercise bench to about 80-90 degrees. Hold a dumbbell in each hand and sit on the bench with your back supported.
2. Let your arms hang down by your sides with your palms facing inward, i.e., a neutral grip. Pull your shoulders down and back and brace your core. Plant your feet firmly on the floor.
3. Bend your elbows and, without turning your wrists, curl the dumbbells up to your shoulders. Keep your upper arms close to your sides.
4. Extend your arms, lower the weights to the starting position, and continue for the desired number of repetitions.

Seated Hammer Curl Benefits

Not sure if seated hammer curls deserve a place in your arm workout? Consider these benefits and then decide:

A time-efficient exercise – working your biceps, brachioradialis, and brachialis simultaneously saves you from having to train these muscles separately, making your workouts more productive and time-efficient. 

Aesthetically-pleasing arms – seated hammer curls work several important lower and upper arm muscles at the same time. These muscles (the biceps, brachioradialis, and brachialis) come together to give your upper and lower arms a powerful, pleasing shape.

A back-friendly arm builder – doing hammer curls while seated means you are less likely to use your legs or back to help you swing the weights up. This not only keeps the tension on the target muscles but also reduces the risk of lower back pain and strain.

A good variation – while regular barbell and dumbbell curls are good exercises, they can become boring if that’s all you ever do. They’ll also start to lose their potency if you do them too often. Adding seated hammer curls to your arm training arsenal means you’ve got a new exercise for your workouts, which will help ward off boredom while increasing workout productivity.

Seated Hammer Curl Drawbacks

While seated hammer curls are a mostly beneficial exercise, there are also some drawbacks to consider:

Equipment – you’ll need an adjustable bench to do this exercise, so it may not be suitable for bodybuilders who train at home. That said, you can do seated hammer curls on a flat bench; you’ll just need to maintain your posture without assistance from a backrest.

7 Seated Hammer Curl Variations and Alternatives

Seated hammer curls are a highly effective arm exercise, but that doesn’t mean you need to do them all the time. There are several variations and alternatives you can use to keep your workouts productive and interesting:

1. Alternating seated hammer curl

Seated hammer curls are usually done with both arms at the same time. This is the most time-efficient way to do this exercise. But, if you prefer, you can use an alternating arm action.

Curling one dumbbell at a time may allow you to use slightly more weight as there is a brief pause between reps, and you’ll be able to focus more mental energy on each arm, reinforcing the mind-muscle connection.

How to do it:

1. Set the backrest on an exercise bench to about 80-90 degrees. Hold a dumbbell in each hand and sit on the bench with your back supported.
2. Let your arms hang down by your sides with your palms facing inward, i.e., a neutral grip. Pull your shoulders down and back and brace your core. Plant your feet firmly on the floor.
3. Bend one arm and curl the weight up to your shoulder. Keep your opposite arm stationary.
4. Lower the weight and then perform your next rep with the other arm.
5. Alternate arms for the required number of reps, ensuring you do the same number on both sides.

2. Standing hammer curl

No bench? No problem! You can do hammer curls while standing. However, you’ll need to work a little harder to keep your torso upright and stationary. If you don’t, you may find yourself leaning from side to side or using your lower back and legs as much as your arms to lift the weight.

How to do it:

1. Stand with your feet about hip-width apart and a dumbbell in each hand. Hold the dumbbells down by your legs with your arms straight and hands turned inward. Brace your core and pull your shoulders down and back.
2. Bend your elbows and, without turning your wrists, curl the dumbbells up to your shoulders. Keep your upper arms close to your sides.
3. Extend your arms, lower the weights to the starting position, and continue for the desired number of repetitions.
4. You can also do this exercise using an alternating arm action – as described above.

3. Cable hammer curl

If dumbbell hammer curls have a disadvantage, it is that the tension on your muscles varies throughout each rep. One second, it’s full-on and very intense, and the next, there is no tension, and your muscles are pretty much relaxed. One way around this problem is to use a cable machine instead of the more usual dumbbells.

How to do it:

1. Attach a rope handle to a low cable machine. Hold the handle with your thumbs against the end stoppers.
2. Stand with your feet shoulder-width apart and upper arms by your sides. Pull your shoulders down and back and brace your core.
3. Bend your elbows and curl the handles up to your shoulders.
4. Extend your arms and repeat.

Related: Cable Hammer Curl Exercise Guide

4. Preacher hammer curl

Preacher curls were one of the exercises favored by bodybuilder Larry Scott, winner of the first (and second!) Mr. Olympia competition. In fact, Scott was so synonymous with this exercise that it was sometimes called Scott curls.

While preacher curls are usually done using a supinated or palms-up grip, you can also use a neutral grip to emphasize the brachioradialis and brachialis muscles, i.e., a preacher hammer curl.

How to do it:

1. Sit on the preacher curl bench with a dumbbell in your hand. Rest your upper arm on the angled pad. Use your free arm for balance and stability.
2. Starting with your arm straight but not locked, bend your elbow and curl the weight up until your forearm is perpendicular to the floor.
3. Extend your arm and repeat. Do the same number of reps on both sides.
4. You can also do this exercise with both arms at the same time.

5. Concentration hammer curl

Concentration curls are so-called because they allow you to really focus on the muscle you are training. They’re usually done with a supinated grip but work just as well with a neutral or hammer grip. Best of all, this exercise is all but cheat-proof as there is no way to swing the weight up.

How to do it:

1. Sit on the end of an exercise bench with your feet about shoulder-width apart. Hold a dumbbell in one hand.
2. Lean forward and place your upper arm against your inner thigh. Let your arm hang straight down. Rotate your wrist, so your thumb is pointing forward.
3. Bend your elbow and curl the weight up to your shoulder.
4. Extend your arm and repeat.
5. Switch arms and do the same number of reps on the other side.

6. Cross body hammer curl

Cross body hammer curls are not necessarily better than regular hammer curls, but they are different. They hit the same muscles but from a slightly different angle, which may be all you need to trigger new muscle growth and avoid training plateaus. Some people find this version more comfortable than standard hammer curls.

How to do it:

1. Stand with your feet about hip-width apart and a dumbbell in each hand. Hold the dumbbells down by your legs with your arms straight and hands turned inward. Brace your core and pull your shoulders down and back.
2. Bend one arm and, without rotating your wrist, curl the weight up and across to your opposite shoulder.
3. Lower your arm and then repeat on the opposite arm.
4. Continue alternating arms for the duration of your set.

7. Neutral grip chin-up

No, you haven’t inadvertently stumbled onto an article about back training! The neutral grip chin-up works many of the same muscles as seated hammer curls. The difference is that, instead of curling the weights up to your shoulders, you curl your body up to the bar. As well as being an excellent arm exercise, this is an elbow-friendly way to train your lats.

How to do it:

1. Using the parallel grip on a pull-up bar, hold the handles and hang with your arms straight and your feet clear of the floor. Pull your shoulders down and back and brace your abs.
2. Without swinging, bend your arms and pull your chin up and over the bar.
3. Descend under control and repeat.
4. Make this exercise harder by wearing a weighted vest or using a chin/dip belt.

Seated Hammer Curl – Wrapping Up

Hammer curls are so-called because, when you do them, you look like you are trying to drive a nail into a sheet of wood. Keeping your hands in a neutral position increases the tension on your brachialis and brachioradialis muscles, as well as working your biceps.

This means that hammer curls are a very productive arm exercise involving both your upper and lower arms.  

That’s not to say you need to drop all other types of barbell and dumbbell curls from your workouts and do nothing but seated hammer curls. This exercise is just one of the many tools you can use to sculpt your arms.

However, if you want to develop the best arms possible, seated dumbbell hammer curls would make an excellent addition to your biceps workouts.

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