How to Do a Hammer Curl

Proper Form, Variations, and Common Mistakes

hammer curls

Verywell / Ben Goldstein

Also Known As: Neutral grip biceps curl

Targets: Upper arm (biceps brachii), lower arm (brachialis, brachioradialis)

Equipment Needed: Dumbbell

Level: Intermediate

The dumbbell curl is one of the most commonly performed exercises for the upper body. The hammer curl is a simple variation of the biceps curl that helps to target additional muscles in the upper and lower arm for greater definition and increased strength. Many believe that this exercise can also help to increase wrist stability and improve your grip strength.

While this exercise is almost always performed with a dumbbell, it can also be performed with cables or bands if a dumbbell is not available. Other typical bicep curl equipment such as a barbell or kettlebell would not be appropriate for this exercise because of the wrist rotation that is necessary.

Benefits

The biceps or biceps brachii is often considered a vanity muscle because they are easily apparent on the front of the body. Men and women looking to get a muscular appearance often target these muscles to get a more athletic look. Other vanity muscles include the pectorals (chest), deltoids (shoulders), trapezius (back) and, of course, the abdominals. But there are other benefits to having strong biceps.

The biceps brachii is an elbow flexor—meaning that it is responsible for the bending movement at the elbow joint so that the lower arm moves closer to the shoulder. It also helps to rotate (supinate) the forearm.

In everyday movements, strong biceps help you to lift and carry heavy objects. These muscles also help with movements like closing a door or pulling objects toward or across your body.

The hammer curl is just one way to build stronger biceps muscles. The traditional biceps curl is the most common exercise used to strengthen this muscle. A barbell curl and preacher curl are variations of the exercise that also work the biceps.

The hammer curl, however, is often cited as being a more effective way to train the arm muscles because many exercisers feel that the rotation involved in the lower arm helps engage the forearm and improve grip strength.

Step-By-Step Instructions

Before you include the hammer curl in your exercise routine, you should have some experience lifting weights. If you are new to this or any weight training exercise, try the movements without weight (or with very little weight) to get comfortable with the movement. You can also work with a fitness trainer to get tips and advice.

To prepare for the exercise, stand with your shoulders relaxed and arms at your sides. Practice good posture by keeping the feet parallel with ankles and knees aligned under the hips. Your legs should be straight but not stiff or locked. Engage the abdominal muscles throughout the exercise to prevent movement through the lower back as you lift and lower your weights.

  1. Place one dumbbell in each hand. Rotate the hands so that the palms face the thighs. By doing so, you'll notice that the thumbs face forward.
  2. Keeping the elbows in a fixed position, flex (bend) at the elbow so the lower arms lift up and toward the shoulders. Keep the shoulders relaxed as you work. Keep your grip firms and wrists in line with the forearm.
  3. At the top of the movement, thumbs will be close to the shoulders, palms facing in toward the midline of the body.
  4. Lower the weights to the starting position.

When first starting out, you may want to try two sets of 7–10 reps each. As you get stronger and more flexible, add repetitions first. Then add more weight.

Common Mistakes

There are a few common blunders that are often seen when performing the hammer curl.

Using Momentum

Exercisers often use a swinging motion to lift their weights during hammer curls or traditional biceps curls. You can tell if you're using momentum if you start the exercise by leaning forward slightly and bringing the weights behind your hips. These movements help you to "wind up" for the workload.

Unfortunately using momentum decreases your ability to build strength with this exercise. Swinging motions may also put you at higher risk for injury because you lose control when momentum takes over. It is not uncommon for exercisers to arch their lower backs if they swing during a curl.

Exercisers who use momentum are often lifting too much weight. If you notice yourself winding up before each repetition, decrease the weight and focus on form.

Curling Too Fast

The hammer curl employs a relatively small range of motion. So it's easy to rush through this exercise and use quick movements, especially during the lowering phase. But you shortchange yourself when you rush.

Experts generally recommend that your concentric or shortening phase (when you lift the weight) should last about two breaths. The eccentric phase or lengthening phase (when you lower the weight) should also last about two breaths. Taking time on the way up and on the way down gives you time to control the movements and focus on form. Slowing your movements also adds a slight challenge because you have to engage the muscles for a longer period of time.

Curling too fast may be a sign that you are not lifting enough weight. Try adding a few pounds to see if that helps you to focus and challenge the muscles.

Floating Elbows

It's easy to allow the elbows to float away from the body during a curl. Moving the elbows allows you to engage other muscles, such as the deltoids (shoulder) to lift the weight. But the more you engage other muscles, the less you target the biceps.

Try to keep the elbows in a stable, fixed position and concentrate on moving the lower arm only during your hammer curl. If you are unable to lift the weight without moving the elbow, you are lifting too much weight.

Modifications and Variations

Need a Modification?

If you try the hammer curl and find that it is too difficult to maintain proper form throughout the movement, consider doing alternating hammer curls. Instead of lifting both arms at the same time, lift the right arm and lower, then lift the left and lower. Continue to alternate sides for 10-15 repetitions.

Up for a Challenge?

There are a few variations of the hammer curl that can make the movement more challenging.

Some exercisers use a preacher bench to perform this move. A preacher bench is simply an angled, padded armrest that allows you to hold the arm in an isolated position so that you can lift more weight and target the biceps.

Another variation is to use a seated incline bench. When seated, the starting position places the arms behind your hips and helps to reduce any shoulder involvement in the exercise.

Safety and Precautions

It is always smart to work with a certified trainer when you begin any new movement. While the hammer curl is appropriate for most exercisers, those with lower arm injuries (such as carpal tunnel syndrome) may need an alternate exercise or modification.

Try It Out

Incorporate this move into one of these strength training workouts. Use the hammer curl in addition to or instead of a traditional biceps curl.

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