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
- Brachioradialis (forearms)
The biceps brachii is a muscle made up of two heads, the short head and the long head.
FREE: The Muscle Building Cheat Sheet. This is a quick guide to building muscle, which you can read online or keep as a PDF, that shows you exactly how to put on muscle. To get a FREE copy of the cheat sheet emailed to you, please click or tap here.
If you look down at your arm, the short head of the biceps 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.
Hammer Curl Variations
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
Incline Hammer Curls
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.
Should I do both hammer curls and bicep curls?
For complete development of the biceps, I like to do at least one exercise with the elbows positioned in front of the body (e.g. preacher curl), another with the elbows positioned behind the body (e.g. incline dumbbell curl), as well as a hammer curl variation.
They don’t necessarily need to be done in the same workout, but I do think it’s a good idea to include all three in your workout routine.
Should I do biceps curls or hammer curls first?
It doesn’t matter too much whether you do biceps curls or hammer curls first. However, I do think it’s important to do your exercises in the same order from one week to the next. This allows you to track your repetition strength from workout to workout, which is a useful way to track your progress.
One of the more reliable signs that your muscles are growing is that your performance in the gym is improving. If you’re able to lift more weight for the same number of reps, or do more reps with the same amount of weight, that’s a good sign your muscles are getting bigger.
Are hammer curls more effective than regular curls?
Hammer curls are more effective than regular curls for working the brachialis muscle, which sits between your biceps and triceps. But they’re not universally more effective than regular curls, they’re just working some of the elbow flexor muscles harder than others. To maximize arm development, you want to include both hammer curls and traditional biceps curls in your training program.
FREE: The Muscle Building Cheat Sheet
If you're overwhelmed and confused by all the conflicting advice out there, then check out The Muscle Building Cheat Sheet.
It's a quick guide to building muscle, which you can read online or keep as a PDF, that shows you exactly how to put on muscle. To get a copy of the cheat sheet sent to you, please enter your email address in the box below, and hit the “send it now” button.
- Muscle Evo – a training program for people who want to build muscle and get strong while minimizing fat gain.
- MX4 – a joint-friendly training program for gaining muscle as fast as humanly possible.
- Gutless – a simple, straightforward, science-backed nutrition system for getting rid of fat.