Hammer Preacher Curl

What the hammer preacher curl actually trains

A hammer preacher curl is an elbow flexion exercise performed with the back of the upper arms resting on an angled preacher pad and the palms facing each other, curling a dumbbell in each hand from full extension to near full flexion.

The brachialis takes a large share of the work, since a neutral grip removes the biceps brachii from its best supinating position. The brachioradialis contributes strongly, and both heads of the biceps brachii still flex the elbow throughout.

Two things define this exercise, and neither of them is mystical.

The first is the pad. With the upper arms fixed against a support, the shoulder cannot help. There is no swing, no hip drive, no leaning back to get a heavy rep up. Whatever the muscle can lift is what goes up, which is why the honest weight on a preacher curl is embarrassing compared to what you can cheat standing.

The second is where the resistance sits. With the arm on a forty five degree pad, the hardest point is early in the rep, when the forearm is closest to horizontal and the moment arm is longest. As you approach the top, the leverage falls away and the exercise gets easy. That is the opposite of a spider curl, where the pad is vertical and the work concentrates near the contraction.

That is genuinely all the difference between these variations amounts to. Marcolin and colleagues compared curl variants and found the loading of the biceps brachii and brachioradialis shifts with arm and grip position, in modest and explicable ways. Nobody has found a curl that builds a muscle another curl cannot.

Setting up and executing

Set the preacher seat so that when you sit down, your armpits are near the top of the pad.

Lay the back of both upper arms flat against the pad and take a dumbbell in each hand with the palms facing each other.

Let the arms straighten fully without slamming into a locked elbow. This bottom position is the part that needs respect.

Brace the abs and keep your chest against the pad.

Curl the dumbbells up towards the shoulders, keeping the wrists straight and the grip neutral throughout. Stop just before the forearms pass vertical, where the resistance disappears.

Lower over about three seconds back to full extension, pause briefly without relaxing, and curl again.

The mistakes that cost you the most

Sitting too low on the pad puts the top edge into your armpit and lets the elbows creep down as you fatigue. Raise the seat until your armpits are at the top of the pad, then set the load.

Dropping out of the bottom is the fault that gives preacher curls their reputation. At full extension on an angled pad the elbow is in a long lever position with the shoulder unable to assist, and letting the weight fall there is how people end up with sore elbows for a fortnight. Roig and colleagues found eccentric training produces greater strength gains than concentric work, which is another reason to own the descent rather than surrender it.

Standing up at the top, lifting the chest off the pad to finish a rep, quietly reintroduces the shoulder you sat down to remove.

Going too heavy is the underlying cause of all three. The preacher position gives you nothing to cheat with, so the correct load is much lower than your standing hammer curl.

And expecting a different muscle sets you up to be disappointed. This is a curl with the arm in front of you, and it loads the brachialis rather than building a peak you were not born with.

Sets, reps and rest by goal

Moderate to high reps only. This is not an exercise to go heavy on.

For muscle gain, three sets of ten to fifteen with ninety seconds rest. For strength, three sets of eight to twelve with two minutes, although preacher curl strength is not a meaningful target. In a fat loss phase, three sets of twelve to twenty with a minute.

Because the top of the range is easy, resist the urge to pause and squeeze at the top; there is nothing to squeeze against. Spend your time at the bottom instead, where the load actually is.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy. Arms respond to total weekly volume far more than to which curl you choose, and adding a fourth curl variation is almost always less useful than adding two more hard sets of the one you already do.

Refalo and colleagues found stopping a rep or two short of failure produces comparable growth to going all the way. On a preacher curl that rule has an extra benefit, since the failed rep is the one where you cannot control the descent.

Where it fits in your split

At the end of a pull or arm session.

On push, pull and legs it goes last on pull day, after the rows and pulldowns. On an upper and lower split it closes the upper session. On a bro split it works as a second biceps movement on arm day. On a full body programme it is usually the first thing to cut, and it should be, unless arm size is a stated priority.

Pair it with a curl that loads the other end of the range. Since the preacher is hardest early and easiest at the top, a spider curl or a cable curl that stays hard as the elbow closes complements it neatly. Doing a preacher curl and an incline curl in the same session is closer to duplication than to coverage, since both concentrate the work near extension.

Once or twice a week is enough.

Variations worth knowing

The standard preacher curl uses a supinated grip on the same pad, biasing the biceps brachii instead of the brachialis. If you only do one, do this one.

The EZ bar preacher curl puts both arms on one bar, which loads and progresses more easily but lets the stronger arm cover for the weaker one.

The machine preacher curl uses a cam to keep the resistance meaningful through the whole range, which fixes the easy top position that the free weight version has.

The single arm hammer preacher curl exposes side to side differences completely and lets you support the working arm with the free hand if needed.

The spider curl, chest down on an incline bench with the arms hanging vertically, is the mirror of the preacher and is hardest near the top.

And the incline hammer curl uses the same neutral grip with the arm behind the body, loading the lengthened position rather than the supported one.

What the evidence says

Marcolin and colleagues compared three curl variants and found that arm and grip position change how the biceps brachii and brachioradialis are loaded, which is the honest basis for choosing a neutral grip when you want more brachialis and brachioradialis work.

Pedrosa and colleagues found training at long muscle lengths produced favourable hypertrophy outcomes compared with short length training, which supports lowering to full extension rather than stopping short, and explains why the bottom of this movement is the part worth protecting.

Schoenfeld and Grgic reviewed range of motion and muscle development and concluded that fuller ranges generally produce better hypertrophy outcomes, which is the reason to use the whole pad rather than pumping the top third.

Vigotsky and colleagues cautioned against interpreting electromyography amplitudes as direct measures of hypertrophy, which is why claims that a hammer grip is a set percentage better than a supinated one should be treated sceptically.

Roig and colleagues found eccentric training produced greater strength gains than concentric training, supporting a controlled three second descent, which on this exercise is also the safest way to handle the bottom position.

Schoenfeld and colleagues found a dose response between weekly hard sets and muscle growth, which remains the variable that decides how your arms respond.

Refalo and colleagues found stopping short of failure produces comparable hypertrophy, which is a sensible rule when the failed rep is the one you cannot lower under control.

Common questions

How is this different from a normal preacher curl?

Only the grip. Palms facing each other rather than up, which takes the biceps brachii out of its strongest supinated position and gives the brachialis and brachioradialis more of the work. Everything else about the exercise is identical.

Is it the same as an incline hammer curl?

No, and the difference is at the shoulder. On a preacher the arm is in front of the body with the shoulder flexed; on an incline it hangs behind with the shoulder extended, which lengthens the biceps long head. If you want one of each, that is the pairing.

Why does my elbow hurt at the bottom?

Almost always because the weight is too heavy and you are dropping into full extension rather than lowering into it. Reduce the load, take three seconds on the way down, and stop just short of a hard lock.

Will this build a taller biceps peak?

No. Neutral grip work builds the brachialis, which adds thickness under the biceps and can make the arm look fuller. Peak height comes from muscle shape and insertion points, which no exercise changes.

Do I need this if I already do hammer curls?

Probably not. A standing or cable hammer curl trains the same muscles with the same grip and allows more load. The preacher version is worth using when you want to remove all cheating, or as a change of stimulus for a block, not as a permanent addition alongside the others.