How to Do Hammer Curls & What Do Hammer Curls Work

Ask any guy about his favorite bicep exercises and he’ll most likely mention hammer curls. This classic variation of the bicep curl engages the brachialis, a muscle that flexes the elbow joint. The brachialis contributes to upper arm thickness to a greater extent than the biceps. 

Despite their popularity, hammer curls are rarely performed with the correct technique. Common mistakes, like gripping the dumbbells in the middle or using momentum to move the weight, can hamper your form and lead to injuries. 

Today we’ll show you how to do hammer curls with perfect form, whether you’re using dumbbells, cables, or resistance bands. 

That’s right — dumbbells are not your only option. If you’re working out at home, you can use elastic bands to perform this movement. 

Our team will also share some tips on how to target your biceps from new angles and what mistakes to avoid when doing a hammer curl. Like with most things, it’s all in the details. 

Build Massive Arms with the Hammer Curl 

The fastest way to add size to your arms is to work the brachialis. This muscle is largely covered by the biceps brachii and originates in the humerus. As the primary flexor of the elbow joint, it plays a key role in arm movement. 

Due to its large cross-sectional area, the brachialis is stronger than the biceps brachii and other surrounding muscles. Generally, it’s more active during isometric movements. The larger this muscle, the more it will push up the biceps when you flex your arm. 

Repetitive forceful contractions can injure the brachialis and the tendons around it. Golfer’s elbow, tennis elbow, and other overuse injuries are common and can cause debilitating pain. That’s why it’s important to do hammer curls — and bicep curls in general — with correct form. 

The hammer curl is one of the best arm exercises for the brachialis. During this exercise, the brachialis acts as a synergist, allowing you to curl the weight up toward the shoulder. 

The primary muscle worked is the brachioradialis, but your biceps, delts, traps, and other smaller muscles come into play too. 

The brachioradialis contributes to elbow flexion and forearm supination and pronation. It also keeps your elbow stable during rapid flexion and extension, such as when you’re doing hammer curls. 

Traditional bicep curls hit these muscles too, but the underhand grip allows your brachialis to share the load with the biceps brachii. 

Hammer curls, on the other hand, require turning your forearm inward. As a result, this movement targets the brachialis more effectively. 

That’s not the only benefit of doing hammer curls, though. Over time, this isolation movement may help improve grip strength and wrist stability. 

Ready to give it a try? Below you’ll find the exact steps to perform hammer curls like a pro. 

How to Perform Standing Hammer Curls 

Let’s start with the standing hammer curl, which can be performed with one arm at a time or both arms simultaneously. 

1. Stand up straight, holding a dumbbell in each hand. Keep your arms extended by your sides, with the palms facing in. 
2. Hold the dumbbells closer to the top end rather than gripping them in the middle. This will take some of the pressure off your wrist so that you can better isolate the biceps. 
3. Keeping your elbows tucked, curl the weight up as far as possible with a slow and controlled motion. Keep your shoulders relaxed and avoiding swinging your arms or hips. 
4. Pause at the top of the movement and squeeze your biceps. At this point, your thumb should be close to your shoulders. 
5. Lower the weight back in a controlled manner and repeat with the other arm. 
6. Perform up to 15 reps with each arm. 

If you have lower back pain, consider doing this exercise from a seated position. 

Set up an adjustable bench at 90 degrees. Keep your back against it throughout the movement and follow the steps listed above. 

The advantage of performing this exercise from a seated position is that it takes the pressure off your back and prevents you from swinging your torso and hips. 

We have dozens of videos on our blog, so check them out to learn proper technique. Start with a lighter weight that allows you to perform about 12 reps with correct form. Consider asking a gym instructor for feedback before you increase the load. 

Avoid These Common Mistakes

Now let’s go over the most common mistakes to avoid when doing a hammer curl. The following rules apply to all variations of the hammer curl, whether you’re using cables, dumbbells, or resistance bands.

First thing first, your upper body should stay still throughout the movement. Make sure you’re not swaying your torso from side to side — that’s cheating. If that sounds like you, then switch to a lighter weight. 

Refrain from swinging the dumbbell or twisting your wrist. These mistakes not only affect your ability to build size and strength but may also put you at risk for injury. 

Moving too fast is just as bad as it reduces the time under tension, limiting your ability to grow. The concentric (shortening) phase should take about two seconds. Squeeze your muscles at the top of the movement for one second or so and then drop the weight back slowly. 

Another common mistake is not getting a full range of movement (ROM). Curl the weight up until your forearm is vertical. If you do it right, you should feel a stretch in your biceps. 

While it’s important to achieve full ROM, you should not move the dumbbell past the tension point. Doing so will allow your bicep and forearm to rest, making the exercise less effective. 

Also, keep your elbows in a fixed position at all times. You should only use your lower arm to move the weight. 

As you already know, the bicep comes into play when you’re training back and other large muscle groups. Therefore, you don’t have to do curls every day or every other day to build bigger arms. This is a relatively small muscle, so it only requires one or two workouts per week.

Hammer Curl Variations

While this exercise is usually performed with dumbbells, you may also cables, bands, or kettlebells. Here are some popular variations you may want to try: 

• Cross-body hammer curls
• Swiss bar hammer curls 
• Incline seated hammer curls
• Preacher hammer curls
• Cable hammer curls
• Kettlebell hammer curl
• Hammer curls with resistance bands

Changing how you perform this movement — or any exercise for that matter — is the best way to avoid strength plateaus. Plus, you’ll hit your muscles from different angles and get a more intense workout. 

Kettlebells hammer curls, for instance, are more challenging compared to the dumbbell version and may help improve shoulder stability. Incline seated curls, on the other hand, allow you to better isolate the brachialis and the long head of the biceps. 

Below we’ll show you how to perform some of the best hammer curl variations to get the most out of your training session. 

Cross-Body Hammer Curls

Like the traditional hammer curl, this movement targets the brachialis, brachioradialis, and biceps. It also helps increase forearm thickness and strength. 

Depending on what equipment you have available, you can use either the cable machine or dumbbells. Simply follow these steps:

1. Stand with a dumbbell in each hand, palms facing in. 
2. Curl the dumbbell in your right arm across the body toward your left shoulder. 
3. Pause at the top of the movement. Hold the contraction for about two seconds. 
4. Bring the weight down with a slow, controlled motion and repeat with your left arm. 

If you’re using a cable machine, set up the pulley close to the floor and attach a handle. Position yourself next to the pulley and perform the movement with one arm as described above. Repeat on the opposite side. 

Both versions work the same muscles as the standard hammer curl, but they put more emphasis on the brachialis and the long head of the biceps. 

Banded Hammer Curls 

Resistance bands are extremely versatile, allowing you to work your muscles from different angles. Compact and lightweight, they’re ideal for bodyweight workouts. 

With resistance bands, you can quickly switch from one exercise to another. For example, you can perform a band squat followed by hammer curls. That’s great for full-body circuits or even HIIT. 

Despite their small size, these accessories can be a viable option to dumbbells and gym machines. They’re particularly effective for upper body exercises, like unilateral rows and lateral pull-downs, reports a 2017 study published in the European Journal of Sport Science. 

Here’s how to do a hammer curl with resistance bands or cables: 

1. Stand with your feet hip-width apart.
2. Place the bands under the arches of your feet. 
3. Grasp the ends of the band in each hand, with your palms facing your thighs. Keep your arms close to your body. 
4. Bend your elbows and bring the band up to your shoulders without moving the upper arms. Make sure your palms are facing each other throughout the movement. 
5. Lower your forearms back and repeat.

Kettlebell Hammer Curls 

This hammer curl variation engages the biceps, brachialis, and forearms, as well as the smaller muscles in your hands and wrist. With regular practice, it can increase forearm and grip strength while adding size to your upper arms. 

When using kettlebells for hammer curls, your arms are under constant tension throughout the movement. This translates into bigger gains in less time. 

Follow these instructions to perform kettlebell hammer curls the right way:  

1. Stand up straight with your feet hip-width apart. Hold a kettlebell in each hand.  
2. Bend your elbows and lift the kettlebells to your shoulders without flexing your wrist. Keep your upper arms and elbows tight to your body. 
3. Lower the weight back in a controlled manner and repeat. Perform this exercise with one arm at a time or both arms simultaneously. 

Choose a kettlebell that’s about half of the weight you’d normally use for hammer curls. One that’s too heavy can lead to wrist injuries and make it harder to maintain good form. Keep your wrists locked when you move the weight. 

Looking for other kettlebell exercises? We’ve got you covered! See our guide to the best kettlebell workouts for full-body gains. 

Get the Most Out of Your Bicep Workouts

Hammer curls are a staple in any bodybuilder’s routine. Whether you’re using dumbbells, kettlebells, or resistance bands, this bicep curl variation can take your gains to a whole new level. The key is to use proper lifting form. 

What makes this exercise so effective is that it targets more than just the biceps. 

If you really want to get the most of hammer curl workouts, consider using our Vintage Brawn protein powder. It delivers 100 calories and 24 grams of protein per serving. Plus, it provides 34% of the daily recommended calcium intake and contains no GMOs, gluten, or artificial colors

As discussed earlier, it also targets the brachialis and forearms, as well as the muscles around your wrist, allowing for better gains and increased grip strength. On top of that, it’s a great choice for drop sets and pyramid sets. 

For best results, perform hammer curls as part of a well-rounded workout that also includes these bicep exercises. Aim for 10 to 15 reps per set and alternate between kettlebells, dumbbells, and cables to keep your muscles guessing. 

What’s your take on hammer curls? Are any alternatives you’d recommend? Drop a few lines below and share your experience!