Preacher Curl

What the preacher curl actually trains

The preacher curl trains the elbow flexors: the biceps brachii, the brachialis underneath it, and the brachioradialis in the forearm. What makes it different from a standing curl is not which muscles work but what the pad prevents.

On a standing curl you can swing at the hips, lean back, and let the shoulders come forward at the top. Each of those is a way of moving the bar without the biceps doing proportionally more work. A preacher bench removes all of them. The upper arms are pinned in front of the torso and the only joint that can move is the elbow.

The arm position matters too. With the upper arms angled forward on the pad, the shoulder is slightly flexed, which means the biceps is somewhat shortened at the start. The consequence is that the bottom of the range is very hard and the top of the range is comparatively easy. That is the opposite profile to an incline curl, where the arms hang behind the torso.

Marcolin and colleagues compared electromyographic activity of the biceps brachii and brachioradialis across curl variations and found that the pattern of contribution shifts with arm and grip position. It is worth taking the general lesson rather than the exact numbers: how you position the shoulder changes what a curl is.

Setting up and executing

Set the seat so that the top of the pad sits under your armpits when you sit down. This is the whole setup and most people skip it. If the pad is too low, your elbows sit above the top edge and the arms can slide, and the position stops doing its job.

Take an EZ bar with an underhand grip roughly shoulder width. Rest the backs of the upper arms flat on the pad with the chest against the top edge and the shoulders down.

Start with the arms almost fully extended. Curl the bar up by bending the elbows, keeping the upper arms flat, and bring it up until the forearms are past vertical and the biceps are fully contracted.

Pause briefly at the top. Do not let the shoulders roll forward to chase a bit more range, because that is the front delt joining in.

Lower over two to three seconds. Stop just short of a locked elbow, reset the shoulders down, and go again. No bouncing.

The mistakes that cost you the most

Not going all the way down is the most common and the most costly. The bottom of a preacher curl is where the biceps is longest and at its worst mechanical advantage, which makes it uncomfortable and makes it the most valuable part of the rep. Pallares and colleagues found that full range training generally produced better adaptations than partial range training, and here the part people skip is precisely the part that distinguishes this exercise from a standing curl.

Bouncing out of the bottom is the fault with actual injury risk. Snapping the elbow straight under load and rebounding puts a sharp stress on the elbow and the biceps tendon. Stop just short of lockout and reverse under control. If you cannot, the weight is wrong.

Shoulders rising off the pad at the top is the classic way to make the last few reps easier. It gives the biceps a rest at the exact moment you wanted tension. Chest stays on the pad.

Sliding the arms up the pad as the set gets hard shortens the lever, which is the same cheat by a different route. Press the armpits into the top edge and keep them there.

And too much weight causes all four. A preacher bench removes every available cheat, so the honest load is lower than your standing curl. Accept that on the first session and the rest is easy.

Sets, reps and rest by goal

The elbow flexors respond well across a wide rep range, but the preacher bench specifically punishes heavy grinding at the bottom.

For muscle gain, three to four sets of eight to twelve with about seventy five seconds of rest. For strength work, three sets of six to ten with ninety seconds, keeping the bottom position controlled. In a fat loss phase, three sets of twelve to fifteen with a minute of rest.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy, and it is worth counting the biceps work your rows and chin-ups already provide before adding a fourth curl variation. Refalo and colleagues found that stopping a rep or two short of failure produces comparable hypertrophy to training to failure, which is particularly relevant here because the failed rep on a preacher curl is the one where the bar drops into a straight elbow.

Where it fits in your split

Curls go after pulling. Fatiguing the biceps before rows and pulldowns costs more on the compounds than it gains.

On push, pull and legs the preacher curl fits on pull day after the rows. On an upper and lower split it sits in the upper accessory block. On a bro split it belongs on arm day.

The most useful way to programme biceps work is by arm position rather than by equipment. One movement with the arms in front of the torso, which is this one, and one with the arms behind it, such as an incline dumbbell curl. Together they cover the biceps at both ends of its length range, and that is more useful than three variations of standing curl.

Variations worth knowing

The EZ bar version is the default. The angled grip lets the wrists sit at an angle they actually like, and it is noticeably more comfortable than a straight bar for most people.

Dumbbells one arm at a time allow full supination, since the hand is free to rotate. They also expose side to side differences that a bar hides by letting the stronger arm compensate.

Machine preacher curls give you a pad, a fixed path and a stack. Nothing to balance and nothing to drop, which makes them the easiest version to take genuinely close to failure.

A cable preacher curl, with a low pulley behind the bench, keeps tension on at the top where a free weight starts giving it back.

Spider curls, done chest-down on a steep incline with the arms hanging vertically, emphasise the top of the range, which is the part a preacher curl leaves comparatively easy.

And the incline dumbbell curl is the mirror image and the natural partner. Arms behind the torso, maximum stretch, hardest at the top.

What the evidence says

Marcolin and colleagues compared biceps brachii and brachioradialis activity across curl variations and found the contributions shift with arm and grip position. That supports programming curls by position rather than treating them as interchangeable.

Youdas and colleagues examined how grip width and forearm rotation affect upper body muscle activation in pulling work, which reinforces the same general point about the hand and forearm position being a real variable rather than a preference.

Pallares and colleagues on range of motion is the reason to insist on the bottom of the rep. Full range beat partial range for adaptations, and on this exercise the bottom is where the difficulty and the distinctive value both sit.

Schoenfeld and colleagues on volume, and Refalo and colleagues on proximity to failure, give the programming. Schoenfeld and colleagues and Roig and colleagues both found small advantages for eccentric-emphasised work, which is the case for the slow lowering.

Vigotsky and colleagues supply the caution: activation amplitudes do not establish which curl builds the most muscle. Use the electromyography work to understand that position matters, not to rank exercises.

Common questions

Why does the preacher curl feel so much harder than a standing curl?

Because it removes every cheat. On a standing curl you can swing, lean back and roll the shoulders forward, all of which move the bar without adding biceps work. The pad prevents all three, so the load you can honestly handle is lower. That is the exercise working, not you getting weaker.

Should I go all the way down?

Yes, to near full extension, but stop just short of a locked elbow. The bottom is the hardest and most valuable part of the range. What you must not do is let the arm snap straight and bounce, which is where elbow and tendon problems come from.

Is the preacher curl better than the incline curl?

Neither is better, they are opposites. The preacher puts the arms in front of the torso and makes the bottom hardest. The incline curl puts the arms behind and stretches the biceps most. Running one of each covers the muscle at both lengths, which is better than choosing.

EZ bar or straight bar?

EZ bar for most people. The angled grip lets the forearms rotate slightly, which takes strain off the wrists. If a straight bar is comfortable for you there is no reason to avoid it, but wrist discomfort on preacher curls is almost always fixed by switching.

Do I need direct biceps work at all if I do chin-ups and rows?

You get real biceps work from both, so if your time is limited you are not neglecting the muscle. But pulling movements load the biceps as an assistant with the arms in a fairly narrow position range, and direct curls let you train it at lengths that pulling does not reach. Two curl variations a week is enough.