How to Build Huge Arms with Hammer Curls: Technique, Benefits, Variations

This extensive guide will teach you everything you need to know about Hammer Curls.

What Are Hammer Curls?

Hammer Curls are a bicep isolation exercise that targets and strengthens the biceps and arms.

Also known as the Dumbbell Hammer Curl or Neutral Grip Dumbbell Curl, this exercise is differentiated from the traditional curl because of the angle of the grip.

In this case both dumbbells are gripped with palm facing each other in a neutral position throughout the full range of motion.

Muscles Worked by Hammer Curls

Muscles worked by Hammer Curls include the long head of the biceps, the branchialis and the brachioradialis (found in the forearms).

The effective exercise also demands work from many upper body stabilising muscles such as the:

  • Upper and middle traps
  • Anterior deltoid (front)
  • Extensor carpi radialis

It is primarily a bicep exercise but Hammer Curls also improve forearm and grip strength, alongside general upper body stability.

The biceps have two heads that begin at the scapula and share the same insertion point.

They are essential for arm movements such as pulling, curling and elbow flexion. Stronger biceps will also help your shoulder health and stabilisation.

From kayaking and rock climbing to carrying a heavy weight, strong biceps are a valuable asset to any human.

Benefits of Hammer Curls

Hammer Curls are an excellent exercise that brings many benefits to your body.

More Muscle Mass for the Biceps

As a bicep exercise, this movement is an excellent way to build muscle mass for the biceps.

Bigger Arms in General

The exercise works the entire arm. This leads to more thickness for both the upper arms and the forearms.

A Fuller, More Functional Arm Exercise

The conventional supinated grip Bicep Curl works the short head of the biceps (creating the peak) but the Hammer Curl activates the long head of the biceps and the brachialis (elbow flexor muscles).

Better Grip Strength

Hammer Curls will help you build a vice like grip. Targeting the brachioradialis muscle in your forearm augments your ability to grip and hold effectively.

A powerful grip will help you with every exercise that involves holding any kind of load.

Strong Woman from Hammer Curls Exercise
Build a powerful grip ©Alora Griffiths

Less Stress on your Wrists

Traditional Bicep Curls, with a barbell or dumbbells, place more stress on your wrists than Hammer Curls.

The neutral position of your hands places more emphasis on your forearms and less on your wrists.

This is also useful because your wrists do not become limitations in your lifting. You can build up good strength gains with Hammer Curls and are less likely to experience pain, twinges or injuries in your wrists.  

Suitable for Everyone

H Curls are accessible and safe. They are useful for everyone, from beginner lifters to seasoned pros.

How to Do Hammer Curls

  • Stand with a dumbbell in each hand and your feet shoulder width apart. Create a solid, grounded base with your body and plant your feet into the ground
  • Maintain a straight back and adjust your hands so that the palms face each other with a neutral grip
  • Inhale and brace your core, abs and glutes. Grip the dumbbells as tightly as possible
  • Squeeze your biceps tight, bend the elbows and start to curl the weight upwards
  • Bring the weight upwards until your forearms touch your biceps
  • Pause and contract your biceps as tightly as you can
  • Slowly lower the weights to the starting position and exhale
  • Pause at the bottom in the starting position with your arms slightly bent. Don’t let the tension out of your arms
  • Repeat for the desired number of reps

Hammer Curls Training Tips

Fix your elbows in the same position throughout the entire range of motion. Don’t let them move around or flay out to the sides.

Don’t let the weights smash into your shoulders.

Stay slow and controlled at all times. This will maximise time under tension and optimise your muscle growth.

Man setting up for deadlift
Strong arms ©Andrew Donovan

Which Build Bigger Arms – Bicep Curls or Hammer Curls?

The simple answer is that both are better for slightly different things. They both target different parts of the arms.

Traditional Bicep Curls are better for building the peak of the bicep.

This is because there is increased activation of the short head of the bicep branchii.

H Curls are better for building overall arm thickness, forearm and wrist strength and general functional ability.  

The latter predominantly works the long head of the bicep brachii as well as the brachialis.

Hammer Curls Sets and Reps

When it comes to muscle growth (hypertrophy) you want to complete 3 – 5 sets of 8 – 12 reps.

Don’t rest for longer than 30 – 45 seconds.

H Curls can (if you want) also cross over into the strength rep ranges if you are looking to improve general functional strength for your arms.

To achieve this, lower the number of reps slightly, take longer breaks and use heavier weights.

Go for 3 – 5 sets of 5 – 8 reps.

Hammer Curl Variations

If you want to keep you training challenging and varied, add the following different types of Hammer Curls into your sessions.

Incline Hammer Curls

For this variation you will need a bench. Set the backrest to a suitable angle and perform the exercise seated. This will enhance the range of motion and stretches the biceps to a greater degree.

Kettlebell H Curls

An excellent challenge, you must stabilise the shifting centre of gravity of the kettlebells through the range of motion. This is tough but will also take your grip strength to the next level.

Cable Hammer Curls with the Rope

Attach the rope to the cable machine then curl the weight stack. This is another excellent test for your grip strength, this variation also maximises time under tension so that you optimise your muscle growth.

Alternating H Curls

Switching the exercise into a unilateral format enables the lifter to concentrate on the form and movement of one arm at a time.

It will additionally help you to identify weaknesses in strength between the left and right arms.

Cross Body Hammer Curl

This variation works unilaterally. Each rep is performed close in towards the body which demands excellent control and stability.

Hammer Curls Alternatives

If you want to train your biceps then consider these alternatives.

  • Banded Curls
  • Barbell Bicep Curls
  • Dumbbell Bicep Curls
  • Incline Dumbbell Bicep Curls
  • Cable Curls
  • Preacher Curls
  • Concentration Curls
  • Swiss Bar Curls

Hammer Curls Standards

The following information from Strength Level is an excellent starting point and we highly recommend you following their advice for the H Curl Standards in lbs.


Hammer Curls Common Mistakes

There are many common mistakes that people make when it comes to Hammer Curls.

Using Momentum to Swing the Dumbbells

Doing this makes the exercise pointless. It is an isolation exercise that is designed to strength and grow your arms and biceps.

Swinging the dumbbells instead of curling and controlling the dumbbells turns it into a crude and ineffective power exercise. This does not lead to muscle growth and gains.

The movement should always be slow and deliberate.

Using Weights that are too Heavy

This is often a cause that that leads to the effect described above. Many people swing the dumbbells because they are not strong enough to lift the weight in a controlled way with excellent form.

Choose weights that you can perform all the reps and sets with good form. The last few reps in every set should feel difficult and place you close to failure.

Negative reps with your training buddy are highly useful when you find yourself in the zone when fatigue is starting to break down good form.

Woman boxing
Strong arms for all sports ©Logan Weaver

Not Working with a Full Range of Motion

Another bad mistake is not reaching the full extension at the bottom of the exercise.

Performing partial reps will minimise results. When it comes to strength and muscle gains, nobody wants this.

Partial reps limit time under tension and avoid full extension. Often this is because full extension is harder to do and takes more effort. That is why it yields better results.

Anatomy of the Biceps

When it comes to understanding H Curls on a deeper level, it makes sense to learn more about the anatomy of the biceps themselves.

What are the Biceps Brachii?

This is a double headed muscle with the same insertion point. It is located in front of the triceps and is commonly known as the biceps.

What is the Long Head of the Bicep Brachii?

The long head of the bicep branchii is a muscle that stretches from the elbow to just above the shoulder joint. It helps to control the movements of both parts of the arm.

The H Curl is an excellent exercise to strength the long head of the bicep branchii.

What is the Short Head of the Bicep Brachii?

The short head of the bicep branchii starts at the top of the scapula and attaches in the same place as the long head at the elbow.

Concentration Curls are an excellent way to develop this muscle.

The second part of the biceps brachii, the short head originates at the top of the scapula and joins with the long head at the elbow. Exercises like concentration curls will work this muscle.

What is the Brachialis?

The branchialis is a tiny muscle that can be found under both the long and short heads of the bicep branchii.

Should You Use Cables or Dumbbells with Hammer Curls?

The traditional Hammer Curl is performed with dumbbells, but executing it with cables can also be a great addition to your training.

Cables can be a good choice if you find that you keep swinging the dumbbells.

Although the best solution to this problem is simply to lower the weight, cables can help an athlete to “grease the groove” for the movement.

The Cable H Curl is great for this because the cable provides tension at all times.

For pure, raw muscle and strength gains you want to use the Hammer Curl with dumbbells.


Got more questions? Scroll through to find the answers.

Why Hammer Curls are Better?

H Curls are not better than Bicep Curls, they simply perform slightly different functions. Depending on your goal, you can choose which one is better for you.

H Curls target the outer head of the biceps and strengthen the wrists and forearms. They are an effective way to build thickness and strength for the full arm.

Bicep Curls build an impressive bicep peak because they target the outer head of the biceps.

What do Hammer Curls Look Like?

Hammer Curls look like a Bicep Curl performed with the palms facing inwards, towards each other in a neutral position.

The overall aesthetic of the movement resembles a hammer, with the arm as the shaft and the dumbbells as the metal heads of the hammer.

Will H Curls Build Big Biceps?

Yes, the exercise will build big biceps. They will increase mass and length as they target the long head of the biceps and the brachialis and the brachioradialis (one of the forearm muscles).

Additionally, they will build bigger, stronger forearms as well.

Should you go Heavy on Hammer Curls?

You should go heavier than you would for bicep curls, but remember that this is still an isolation exercise that places stress on the elbows and wrists.

The aim is to build muscle and strength, not try to achieve some pointless 1rep max with terrible form that damages the wrists, elbows and shoulders.

Can you do Hammer Curls One Arm at a Time?

Yes, you can do the exercise one arm at a time. This will help you to control the movement, create a great amount of time under tension, identify weaknesses and improve general coordination.

Where Should you Feel Hammer Curls?

If the exercise is done properly, you will feel a stretch in your biceps and forearms.

Should I do Hammer Curls?

If you want bigger, stronger, more functional arms then H Curls should be a part of your training.

They are suitable for athletes of all abilities and training histories so yes, you should do them.

Are Seated or Standing H Curls Better?

Seated H Curls make it harder to cheat by using momentum. They also allow you to add an incline which is an effective training stimulus.

Standing H Curls make your core work harder to stabilise the movement.

Both build strength and muscle mass.

Why do Hammer Curls Hurt?

If the exercise hurts you then your wrists and forearms may not be strong enough for that particular weight. Try a lighter load.

If the problem persists with any weight, then there could be underlying shoulder, elbow or wrist injuries that need attention. Consult a professional physio.

Remember that isolation exercises require the use of tendons, ligaments and connective tissue. These need time to develop as well, just like the muscles that are involved in the movement.

What’s the Difference Between Hammer Curls and Cross Body H Curls?

Hammer Curls are performed out in front of the body.

They develop the biceps and branchioradialis, a muscle on top of the forearm.

Cross Body H Curls are executed tucked in close to the body.

They target the biceps and place emphasis on the muscle that runs between your biceps and triceps. This also works the deeper muscles of the forearms.  

Learn More

Add Preacher Curls and Skull Crushers into your training.

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