How to Do the Cable Hammer Curl for Strong Biceps and Forearms

If your goal is to build strength and mass in your biceps and forearms, the cable hammer curl should be included in your exercise routine. The hand placement means less stress on your arm joints, making this an ideal upper-body exercise.

You will need a cable pulley machine to do this move, however, most gyms have this machine. "Cables are a great way for any muscle to experience a lot of stress on the tissue in a consistent manner — and they also make it a little easier to control, versus a free weight," Joey Thurman, CPT, author of ‌‌‌The Minimum Method: The Least You Can Do to be a Stronger, Healthier, Happier You‌‌‌, says.

Read on to learn more about how to do the cable hammer curl, the muscles worked, benefits, form tips, variations and how to add it to your workout routine.

• ‌What is a cable hammer curl?‌ This exercise is a variation of the biceps curl, however, you keep your palms facing each other throughout the move in what is called a neutral grip. (With a regular biceps curl, your palms are facing up.) You perform the curl while holding onto either the rope or handle attachment on the cable pulley machine. You can also do this exercise by holding onto dumbbells.
• ‌Who can do it?‌ This move is ideal for those wanting to strengthen, tone, or build mass in their biceps and forearms. It also helps increase grip strength. If you have a bicep or arm injury (shoulder, elbow, or hand), talk to your doctor before doing this move. This exercise shouldn't hurt, so stop if you feel pain.
• ‌What muscles does the cable hammer curl work?‌ This exercise strengthens the muscles that bend your elbow, which includes your biceps brachii, brachioradialis and brachialis muscles. The biceps brachii is the most superficial muscle and gives you the muscle mass on the front of your arm, while the brachioradialis gives you the muscle mass in your forearm. The brachialis also goes into your forearm but is mostly covered by the biceps brachii. Cable hammer curls also increase your grip strength as you hold onto the rope or handle.
• ‌What is the difference between cable curl and cable hammer curl?‌ A cable hammer curl works the muscles in your upper arm ‌and‌ forearm, whereas a cable curl (or biceps curl) mainly works the upper arm muscles. They also work different parts of the bicep brachii. "A regular cable curl with a supinated or 'palms up grip' works the short head of the biceps brachii," Thurman says. "A hammer curl using a neutral grip 'palms facing each other' hits the long head of the biceps brachii (the outer part of the biceps), as well as the brachioradialis and brachialis muscles of the forearm. The hammer curl is often easier to do as there is a pause at the bottom of the position, and the forearms also assist in the movement."
• ‌Is it better than a dumbbell hammer curl?‌ "There isn't a 'better' exercise, but one that is better for you and your body," Thurman explains. "Some people may prefer cables and machines over free weights. Cables are great as you can put the biceps in more of a lengthened position to get a full contraction out of the tissues with less momentum." A 2020 study in the ‌Journal of Strength and Conditioning Research‌ actually found no difference in muscle mass and strength between training with free weights versus weight machines. "The best exercises are what you feel and see the most results from," Thurman says.

Cable hammer curls have many benefits if you want to strengthen your upper body. If you don't have access to a cable pulley machine, you can do hammer curls with a dumbbell to get similar benefits.

Both cable hammer curls and a regular biceps curl will strengthen your biceps brachii pretty much to the same degree, found a 2023 study in ‌Sports (Basel)‌. Because of the neutral or "palms in" grip, cable hammer curls also work the forearm muscles (brachioradialis and brachialis), whereas a biceps curl mainly just works the biceps brachii. This is beneficial if you want to build up mass and strength in your forearms, as well as your arms.

Because you are gripping onto handles or a rope, cable hammer curls increase your grip strength and strengthen your wrist muscles to improve overall wrist stability. A strong grip not only helps you lift heavier weights but also is beneficial for everyday activities like carrying groceries or opening jars.

Because of the neutral grip position, hammer curls place less stress on your joints because your forearm muscles and biceps muscle (biceps brachii) are working together. With a biceps curl, the palms-up position can place more stress on your wrist, which can be painful if you have a wrist injury.

A cable hammer curl also puts less stress on your elbow, which can be beneficial for those who have tennis elbow or other elbow injuries. If you have a shoulder injury, such as tendonitis or rotator cuff injury, a hammer curl will also allow you to strengthen your biceps without as much stress on your shoulder.

Unlike free weights, the cables are designed to provide tension throughout the full range of motion, meaning there's ability to rest at the top and bottom of the move. In addition, cables may be safer for beginners as the machine provides some stability and control, allowing you to focus on your technique.

"The hammer curl on a cable machine is a great way to get a full range of motion and work the biceps and forearms in one quick and easy-to-set-up movement," Thurman says. In addition to cable hammer curls, you can do several upper and lower body exercises on cable pulley machines. And while they may look intimidating, it's simple to swap weights just by moving the pin, and grips are easy to change, too.

Maximize the benefits of the cable hammer curl by avoiding these common form mistakes:

Thurman says that swinging the weight, either with your arms or body, is one of the top mistakes with the cable hammer curl. If you don't keep your elbows fixed to your side and core engaged throughout the movement, you'll end up working other muscles — such as the deltoids — instead of the biceps. Swinging also means you're using momentum instead of your muscles, so you aren't getting the full benefit of the exercise.

Focus on moving just your lower arm by bending your elbow and keeping your core strong. If you can't perform the move without swinging, you should lower the weight.

Another common form mistake, according to Thurman, is not taking the exercise through the full range of motion. Make sure you are bending your elbows all the way up — and then lowering them all the way down until your arms are straight (but not locked). This allows your muscles to get the full strengthening benefits.

If you are unable to move through the entire range of motion you may have the weight too heavy — or you may be performing the motion too quickly.

Thurman says if you have the weight too light, you are prone to curling too quickly, which can turn this move into cardio instead of resistance training. The motion should be slow and controlled, both up and down. The weight should be heavy enough that the last few reps are difficult, however, you can still maintain correct form.

It is also important the cable pulley machine is set up correctly, says Thurman. You must attach the handle or rope attachment to the lower pulley and stand, facing the machine, about 10 to 12 inches away. You may need to adjust the height of the pulley, depending on how tall you are, so you have constant tension during the move.

Whether you want it more or less difficult, there are other variations of the cable hammer curl to challenge yourself.

Using the rope attachment, with your hands still parallel and keeping the ropes taut, strengthens your grip more than the handle attachment. It also allows more flexibility with wrist angle, which can be beneficial if you have had a wrist injury. You can try both attachments to see which one you prefer.

Sitting on a large exercise ball while performing this move provides an unstable surface that challenges and works your core muscles.

This exercise is a great way to work your lower body, upper body and core all at the same time. This is a more advanced move and should be done after you have mastered the basic cable hammer curl.

The cable hammer curl is a great exercise to add to your arm strengthening workout, which also can include bicep curls, rows, lat pull-downs and tricep work. Doing both bicep curls and hammer curls is an excellent way to build mass in both your arms and forearms.

It is important to keep your fitness goals in mind when starting a resistance exercise program so you can ensure you are doing the correct reps, sets and weights.

Here's how many reps and sets to do, depending on your goal:

• ‌Building muscle mass:‌ Do 6 to 12 reps for 2 to 6 sets, and rest 30 to 90 seconds between sets.
• ‌Strength:‌ Do 6 reps for 2 to 6 sets, and rest 2 to 5 minutes.
• ‌Endurance:‌ Do 12 or more reps for 2 to 3 sets, and rest for 30 seconds or less.

As far as weight, the last few reps should be very challenging. If they aren't, you should increase the weight. If you can't maintain proper form or feel pain, lower the weight.