Brachialis Exercises: Hammer Curls, Reverse Curls & More

What the brachialis and brachioradialis do

Before you pick brachialis exercises, it helps to know where the muscle attaches. The brachialis sits under your biceps on the front of the upper arm. A dissection study of 11 cadaver arms found two heads; the muscle runs from the front of the humerus to the ulna, attaching at the ulnar tuberosity and the coronoid process, while the biceps attaches to the radius.

That detail matters because the ulna does not rotate when you turn your palm; the radius rolls around it. The brachialis therefore bends the elbow with the same line of pull in every grip. The biceps has two jobs, bending the elbow and turning the palm up (supination), so grip changes how well it can do the first one.

The brachioradialis runs from the lower humerus along the thumb side of the forearm to the radius near the wrist. It is thin but attaches far from the elbow, which gives it a long lever. All three muscles are elbow flexors, and the biceps hub lists exercises for the whole group.

Forearm position decides who does the work

Grip changes the leverage of the biceps but not the line of pull of the brachialis. A cadaver and computer-model study showed the biceps has a larger elbow-flexion moment arm with the palm up, as in a standard dumbbell curl. It also showed that elbow moment arms varied by at least 30% over a 95° range of motion, so leverage shifts through every rep.

Turn the palm in (hammer grip) or down (reverse grip) and the biceps loses some leverage while the brachialis keeps all of its own. A larger share of the work then plausibly falls on the brachialis and brachioradialis, though that is reasoning from anatomy, not a measured growth result. In line with it, an isometric EMG study in 20 people found that adding supination effort raised biceps EMG, while pronation effort shifted activity toward the brachioradialis.

Data on the brachioradialis itself conflict. An EMG study in 16 adults curling without added load found it worked relatively harder with the palm down, with hammer and palm-up grips looking similar. A fine-wire EMG study in 10 adults at light loads found no grip difference, and a maximal-effort EMG study in 15 men found all three elbow flexors highly active in every grip.

Remember what EMG measures: electrical activity during the exercise, not growth. A 2022 review concluded that acute EMG amplitude is not a validated predictor of muscle growth, so read these results as clues about how the work is shared, not as growth rankings.

The brachialis exercises worth your sets

This ranking is a coaching judgment: first how directly each lift shifts work toward the brachialis and brachioradialis, then what data exist. For the biceps-first view, read what the research says about the best biceps exercises, and for a full catalogue see the bicep curl variations guide. Because the same grips load both muscles, the list doubles as a set of brachioradialis exercises.

Hammer curls keep your palms facing each other, so the biceps works at reduced leverage while the brachialis keeps its usual leverage, and the lift still loads well. An EMG study of four curls in 15 adults at light loads found hammer curls produced the lowest biceps activity, which fits that picture without showing more brachialis growth. The rope cable version gives smoother loading and smaller weight jumps.

Reverse EZ-bar curls turn the palms down, the grip in which the brachioradialis looked most active in the unloaded EMG study above. Expect to lift clearly less than in a normal curl, because grip and wrist strength often limit the set. The angled EZ handles are easier on the wrists than a straight bar for many people.

Preacher curls have the only direct growth data. A 12-week MRI trial in 21 untrained adults trained one arm with preacher curls and the other with incline curls: the brachialis grew 21.1% versus 17.1%, and the brachioradialis 17.6% versus 13.5%. Total elbow-flexor growth was similar (19.2% versus 17.6%), and the biceps grew 18.9% with preacher curls, so they train the biceps well too.

The pad makes the curl hardest near the bottom, where the elbow flexors are stretched, and it keeps the upper arm in front of you. The trial could not separate those two factors. The short-head guide covers what arm position means for the biceps.

Chin-ups, pulldowns and rows bend the elbow against heavy loads. A 10-week randomized trial in 29 untrained men found wide, palm-down lat pulldowns alone grew the elbow flexors about as much as barbell curls alone (6.10% versus 5.83%). That result comes from beginners, so if you are trained, treat the pulls on your pull day as a base, not a replacement for curls.

Does the brachialis make your arms look wider?

The argument is anatomical. The brachialis lies under the biceps, so a thicker brachialis could push the biceps outward and add width, especially when the arm is seen from the side. It is plausible, but no study has measured whether brachialis growth changes how wide the arm looks.

Treat it as a reason to include some brachialis work, not as a promise. Since no growth trial has compared grips, the lever you control for arm size is hard weekly sets for all three elbow flexors.

Brachialis vs biceps: which is stronger?

There is no simple answer. Elbow strength depends on muscle size and leverage, and both change with elbow angle and grip. The cadaver data used here include no brachialis force values, so they cannot rank it against the biceps.

They do show how leverage can make up for size. Cadaver measurements of 10 arms found the brachioradialis had the smallest physiological cross-sectional area (1.2 cm²) of the muscles studied but a relatively large moment-generating capacity (6.8 cm³), thanks to an average peak moment arm of 7.7 cm. The biceps long head had a 4.7 cm moment arm and changed length by 56% of its optimal length as the elbow moved.

In practice, all three muscles work in every curl and chin-up. The training question is how much total work they get, not which one wins.

Sets, reps and weekly volume

Brachialis work adds to your biceps volume rather than standing apart from it. A 2026 meta-regression of 67 studies found growth kept rising with weekly sets, with diminishing returns, and it counted indirect sets as half a set because that method fit the data best. With that bookkeeping, a set of rows or chin-ups counts as half a set for the elbow flexors; the sets per muscle guide explains the method.

Pulling alone can grow the arms. An 8-week trial in 34 trained men who did no curls found elbow-flexor thickness grew more with five sets per exercise than with one, and the one-set group already did 6–9 weekly sets per muscle group. More weekly work helped, but no study gives an exact best number for the arms.

• Brachialis-biased curls (hammer, reverse, preacher): 4–10 hard sets per week over two sessions, as a starting range.
• Hammer and rope hammer curls: 8–15 reps.
• Reverse EZ-bar curls: 10–15 reps, since grip limits heavy loads.
• Preacher curls: 8–12 reps.
• Add sets only when progress stalls and you recover well between sessions.

You do not need to grind every set to failure. A 2022 meta-analysis of 15 studies found failure was not required for growth or strength, and did not harm them either. Ending most sets 1–2 reps short is a practical default, and the RPE calculator helps you rate that.

Load can vary too. A meta-analysis of 21 trials found light (≤60% 1RM) and heavier (>60% 1RM) loads built similar muscle when sets went to failure, while heavy loads built more 1RM strength. Because those sets reached failure, light sets only make sense if you finish them close to it.

Technique cues for the top picks

Hammer curl

• Stand tall with your elbows at your sides and your palms facing each other.
• Curl without letting the elbows drift forward.
• Lower over 2–3 seconds to a straight elbow.
• With the rope, keep the ends level and pull them slightly apart at the top.
• End the set when you need a swing to finish a rep.

Reverse EZ-bar curl

• Take the angled grips palms down, about shoulder width apart.
• Keep your knuckles in line with your forearms; do not let the wrists droop.
• Choose a load you can lower under control for 10 or more reps.

Preacher curl

• Set the seat so your armpit sits snugly on top of the pad.
• Lower until your elbow is almost straight, under control, with no bounce.
• Keep the back of your upper arm on the pad for the whole rep.

Regressions and progressions

Progress each lift with double progression: work up to the top of the rep range on every set, then add the smallest load step and start again at the bottom. The progressive overload calculator can map those steps.

A sample arm session with brachialis work

Run this brachialis workout once a week, with triceps work between exercises if you like, as in the arm workout. On a second day, add two sets of hammer curls after your rows. That totals nine brachialis-biased sets plus your pulling, inside the range above. If you train at home, the dumbbell biceps guide swaps in options that need only dumbbells.

Common mistakes

• Expecting hammer curls to isolate the brachialis; every curl trains all three elbow flexors.
• Swinging your torso, which moves load away from the arms.
• Letting the wrists droop on reverse curls, so the wrist extensors give out before the elbow flexors.
• Cutting off the bottom of the range, where the elbow flexors are stretched.
• Adding brachialis sets on top of heavy pulling without counting the total.
• Training through sharp elbow pain; stop and see a qualified clinician instead.

What the research cannot tell you yet

• No growth trial has compared hammer or reverse curls with other curls.
• EMG studies disagree on which grip works the brachioradialis most, and EMG does not measure growth.
• Only one MRI trial has measured the brachialis and brachioradialis separately, and it compared incline with preacher curls, not grips.
• No study has measured whether brachialis growth makes the arm look wider.
• Most studies here used small groups of untrained people.

Until those trials exist, choose lifts by mechanism, progress them steadily and let your training log show what works for you. A few hard sets of hammer, reverse and preacher curls each week covers every grip at little cost.