Cross Body Hammer Curl: How to Do It and Muscles Worked

The cross body hammer curl is a neutral-grip dumbbell curl where you bring the weight across the front of your torso towards the opposite shoulder, one arm at a time, instead of straight up in front of you. It trains the same muscles as a standard hammer curl (brachialis, brachioradialis and biceps), and its real advantage is practical: the path across your body makes it much harder to swing the weight or let your wrist roll open. Some gyms call it the pinwheel curl. Same lift.

If you want the basic version first, our hammer curls guide covers it. This page is about the across-the-body variation only: how to do it, what the evidence says about the muscles involved, and when it earns a place over the standard curl.

How to do a cross body hammer curl

You need one pair of dumbbells and enough room to stand. Start a size lighter than your usual hammer curl weight for the first session, because the path feels odd until you've done 20 or 30 reps.

1. Set up. Stand with your feet hip-width apart and a dumbbell in each hand, palms facing your thighs and thumbs pointing forwards. Pull your shoulders down and tighten your stomach so your ribs don't flare.
2. Fix the elbow. Keep your working upper arm against your side. It stays there for the whole rep; only the forearm moves.
3. Curl across. Bend your right elbow and bring the dumbbell diagonally across your body towards your left pec, keeping the thumb side of the dumbbell leading. Your forearm should finish across your chest with the top of the dumbbell near your left collarbone.
4. Pause. Hold for one second at the top. Your wrist should be straight, in line with your forearm, and your palm should face your chest.
5. Lower slowly. Take two to three seconds to return along the same diagonal line until your arm is straight at your side, then repeat on the left.

Breathe out as you curl and in as you lower. Your torso shouldn't rotate to meet the dumbbell; if your chest turns towards the working arm, drop the weight by 2kg and try again.

Muscles worked

Three muscles bend the elbow, and the cross body hammer curl uses all of them.

Brachialis. This is the muscle the lift is usually sold on. It sits underneath the biceps, attaches to the ulna and does nothing except flex the elbow, so it works whichever way your palm faces (anatomy reference, StatPearls). A neutral grip doesn't make it work harder in absolute terms. What it does is ask less of the biceps, which leaves the brachialis with more of the job.

Brachioradialis. The thick muscle on the thumb side of your forearm, just below the elbow. It's a strong elbow flexor with the hand neutral or pronated, and it's the reason your forearm aches after a hard set.

Biceps brachii. Both heads still work. In a study of 10 competitive bodybuilders curling an 8-rep-max load, biceps excitation was about 12% higher with a palms-up grip than a neutral one during the lifting phase (handgrip and biceps curl EMG study). So the hammer grip costs the biceps a little, not a lot.

What the evidence does and doesn't show

Here's where we have to be straight with you: we searched PubMed Central and couldn't find a single EMG or training study on the cross body hammer curl itself. Everything written about its muscle activation, on this page and everywhere else, is inferred from research on grip position in ordinary curls.

That research is less tidy than the gym folklore. The bodybuilder study above found brachioradialis excitation was slightly higher with a supinated grip than a neutral one, by around 6%. An earlier study of 16 adults doing slow elbow flexion found the brachioradialis contributed most with the palm down, with no clear difference between neutral and palm up (Kleiber et al., 2015). Neither result supports the idea that a hammer grip is uniquely good for the forearm.

The brachialis is harder still to pin down, because it lies under the biceps and most curl studies don't record it. A small 2021 study in six men showed surface electrodes can pick up the brachialis separately from the biceps, but only during unloaded elbow flexion (brachialis surface EMG study). Nobody has yet used that method to compare curl variations under load.

The claim that curling across the body targets the long head of the biceps has no direct evidence behind it either. If you're curious about how the two heads differ, read our piece on long vs short biceps.

So the sensible position is this: the lift trains all three elbow flexors, the neutral grip tilts the balance slightly away from the biceps, and the across-the-body path hasn't been shown to change which muscles fire. Its benefits are mechanical and practical.

Cross body vs standard hammer curl

The grip is identical. What changes is the direction the dumbbell travels and what that does to your form.

	Standard hammer curl	Cross body hammer curl
Path	Straight up in front of the shoulder	Diagonally towards the opposite pec
Arms	Both together or alternating	One at a time
Range at the top	Dumbbell reaches the shoulder	Stops a little earlier, at the chest
Easiest way to cheat	Swinging the hips, elbows drifting forwards	Twisting the torso
Wrist	Can roll towards palms-up	Your chest blocks the roll
Time per set	Shorter	Roughly double if you alternate

Three practical differences come out of that table. Your torso sits in the way, so it's physically awkward to supinate the wrist and turn the rep into a normal curl. The elbow tends to stay pinned because there's nowhere useful for it to go. And because you only move one dumbbell at a time, there's less total load pulling you forwards, which is why many lifters find they can go one step heavier than on the two-arm version.

The cost is a slightly shorter range at the top and a longer set. Neither matters much.

If you're still deciding between a neutral and a palms-up grip in the first place, hammer curl vs bicep curl covers that comparison in detail.

Common mistakes

Twisting to meet the weight. This is the cross-body equivalent of swinging. Your shoulders should stay square to the front for every rep, and filming one set from head on will show you straight away if they don't.

Letting the elbow flare out. When the upper arm lifts away from your side, the movement becomes a sort of upright row and your deltoid takes over. Keep the elbow against your ribs.

Curling to the middle of your chest. Stopping at your sternum cuts the range by a good few centimetres. Finish with the dumbbell near the opposite collarbone.

Bending the wrist back. A heavy dumbbell will try to tip your wrist into extension, which loads the joint and takes tension off the forearm. Squeeze the handle hard and keep your knuckles stacked over your wrist.

Dropping the negative. Lower for a full two seconds at least. If you can't, the weight is too heavy for you today.

Variations

• Alternating vs one arm at a time. Alternating (right, left, right, left) gives each arm a few seconds' rest and suits heavier sets of 6 to 10. Finishing all reps on one side before switching keeps tension on longer, and it works better for 12 to 15 reps with a lighter dumbbell. A third option is to hold the resting arm at 90 degrees while the other curls, which is brutal on the forearms.
• Cable cross body curl. Stand side-on to a low pulley with a single handle or one end of a rope, and curl across your body with a neutral grip. Unlike a dumbbell, the cable keeps pulling at the top and bottom of the rep, where gravity gives you a rest. See our cable bicep curl guide for setup.
• Incline cross body hammer curl. Lie back on a bench set to around 60 degrees and curl across your chest. The bench stops any hip swing. Don't expect the stretched shoulder position to add size by itself, though: a 10-week study of 24 untrained men found no meaningful difference in elbow flexor growth between cable curls done with the shoulder extended and neutral.
• Seated cross body curl. Sitting upright on a bench removes leg drive. You'll need to angle the dumbbell slightly to clear your thigh at the bottom.
• Slow-lowering version. Curl up in one second and lower in four. Use about 20% less weight.

For other ways to hit the same muscles with a different grip, the reverse curl puts your palms down and the Zottman curl combines a palms-up lift with a palms-down lower.

Sets, reps and load

Treat this as a moderate-rep accessory lift; heavy triples aren't worth it on a single-joint exercise where grip and form go first.

• Muscle size: 3 sets of 8 to 12 reps per arm, 60 to 90 seconds' rest.
• Forearm and grip focus: 2 to 3 sets of 12 to 15 reps per arm with a slow lower.
• Beginners: 2 sets of 10 per arm, twice a week.

Stop each set one or two reps short of the point where your form would break. Once you can do 12 clean reps on every set, move up by the smallest step available and build back from 8.

Not sure where to start? Most beginner women start curls on 3kg to 5kg and men on 6kg to 10kg, and our guide to what weight dumbbells you should use gives a proper method for finding your number.

Small jumps matter more here than on big lifts. Going from 10kg to 12.5kg is a 25% increase, which can turn 12 reps into 6 overnight. That's the argument for adjustable dumbbells with fine increments. The NÜOBELL 232, the top pick in our best adjustable dumbbells UK roundup, adjusts from 2kg to 32kg per hand in 2kg steps; the pair costs around £670 at the time of writing, so it only makes sense if you'll use it for pressing and rowing as well.

Check NÜOBELL 232 price on Amazon

On a tighter budget, a fixed or spin-lock set from our best dumbbell set UK guide does the job for far less.

Where it fits in a programme

Put it after your rows, pull-ups or chin-ups, which already work the elbow flexors with far more load. Curling first would tire your grip and cost you reps on the lifts that matter more.

Six to twelve hard sets of direct curling a week is plenty for most people, and cross body hammer curls should take up 3 to 6 of those. A simple split across two sessions:

Day	Exercise	Sets x reps
Pull or upper day 1	Incline dumbbell curl (palms up)	3 x 8 to 12
Pull or upper day 1	Cross body hammer curl	3 x 10 to 12 per arm
Pull or upper day 2	Cable or EZ bar curl	3 x 8 to 12
Pull or upper day 2	Reverse curl	2 x 12 to 15

That covers a supinated, a neutral and a pronated grip across the week without piling on volume. If your forearms are the priority, swap the reverse curl for a second round of cross body curls and add the wrist work from our forearm exercises guide.

You don't need both the standard and cross body hammer curl in the same week. Pick one, run it for 8 to 12 weeks while adding weight or reps, then swap if you're bored.

Recommended reads

• Hammer curls: how to do them and muscles worked
• Hammer curl vs bicep curl
• The best adjustable dumbbells in the UK
• What weight dumbbells should I use?
• The best forearm exercises