Cross Body Hammer Curl vs Hammer Curl: Which Is Best?

If you want to know what the cross-body hammer curl is, what muscles it works, and how it compares to a regular hammer curl, this page will tell you everything you need to know.

What is the Cross Body Hammer Curl?

The cross body hammer curl is an isolation exercise used to train the muscles in your upper arms and forearms.

Compared to regular dumbbell curls, which are done with the palms facing forwards, the hammer curl is done with the palms facing your body. The thumb is on top, a bit like a carpenter holding a hammer.

Changing the position of your hands in this way means that certain arm muscles are doing more of the work compared to the regular dumbbell curl.

How does the cross body hammer curl differ from standard hammer curls? Is one better than the other?

With the standard dumbbell hammer curl, rather than lift your arm across your body as you do with cross body curls, the movement path is straight up and straight down.

Standard hammer curls work brachioradialis, brachialis and the long head of the biceps. Cross body hammer curls, where you turn the arm in, work the same muscles. However, they do hit the long head of the biceps a little harder than standard hammer curls.

Brachialis doesn’t cross the shoulder joint, so rotating the shoulder shouldn’t have an impact on the brachialis. It’s much the same story with brachioradialis, which is a single-joint muscle crossing the elbow.

The long head of biceps brachii does cross the shoulder joint, so it’s possible that cross body hammer curls may place more of an emphasis on the long head of the biceps than the standard hammer curl.

However, any difference between the two exercises in terms of their ability to stimulate growth in the arms is likely to be small, and you should pick the one that feels like it’s working the target muscles the hardest.

Cross Body Hammer Curl: Muscles Worked

• Biceps brachii 
• Brachialis
• Brachioradialis (forearms)

The biceps brachii is a muscle made up of two heads, the short head and the long head.

If you look down at your biceps, the short head is found on the inside of your arm, near your body. The long head is found on the outside of the arm.

With cross body curls, you’re targeting primarily the long head of the biceps, along with a small muscle found just underneath the biceps, known as brachialis. 

You can see what a well developed brachialis looks like in the image below. You’ve got the biceps on top, the triceps on the bottom, with the brachialis sitting between the two.

The cross body hammer curl also works the forearm muscles, specifically a muscle that sits on top of your forearm known as brachioradialis. Like the biceps and brachialis, brachioradialis helps to flex, or bend, the elbow.

How to Do Cross Body Hammer Curls: Proper Form

Although you can do cross body curls with two dumbbells, alternating from one side to the other, I prefer to train one arm at a time.

Stand with your feet roughly shoulder width apart and a dumbbell in your right hand, using a neutral grip position (palms facing you). This is your starting position.

Twist your upper body slightly, so your right shoulder comes forward and your left shoulder moves back.

Slowly curl the weight across your body towards the left shoulder. 

During each rep, your wrists should remain in a neutral position, as if you were holding a hammer and preparing to hammer a nail into a plank of wood.

Pause briefly at the top, before lowering the dumbbell under control to the starting position.

Don’t worry about keeping the elbow stationary. As you can see in the video above, it’s normal for there to be a small amount of elbow movement as you complete each rep.

The muscles involved in this exercise are relatively small, so you don’t need to use a heavy weight. Instead, focus on proper form, using a full range of motion. 

In most cases, you’re better off using relatively light weights, and a smooth, controlled lifting speed. Sets of 8-12 reps, 12-15 reps or even 15-20 reps with a lighter load can all be used to build muscle.

Alternative Exercises

Cable Rope Hammer Curls

As well as dumbbells, you can also do hammer curls with a rope attachment attached to a cable machine.

Reverse-Grip Barbell or EZ Bar Curl

Reverse curls, done with a barbell or EZ curl bar, involve elbow flexion with a pronated grip, which requires even more work from brachioradialis, the muscle that sits on top of your forearm.

Hammer Concentration Curl

Swiss Bar Hammer Curl

Frequently Asked Questions

Which biceps head gives the peak?

The biceps comprise two heads: the long (outer) head, and the short (inner) head. It’s the long head that gives the biceps its peak. If you want more of a biceps peak, focus on building the long head.

Are hammer curls better than reverse curls?

Hammer curls aren’t necessarily better than reverse curls, they’re just working certain muscles harder than others. Reverse curls don’t hit the biceps as hard as hammer curls, and require more work from a muscle in your forearm known as brachioradialis.

Is it better to do hammer curls standing or sitting?

The only downside with seated hammer curls is that the dumbbells (depending on the type of dumbbell you’re using) can end up hitting your thighs. That’s why I prefer to do them standing up. But in terms of the muscles being worked, both seated and standing hammer curls are equally effective.