Barbell Preacher Curl

Target muscle: Brachialis
Synergist muscles: Biceps Brachii, Brachioradialis
Equipment: Barbell
Body part: Upper Arms
Type: Strength

The barbell preacher curl is an isolation exercise that builds the upper-arm flexors with your arms anchored on the angled pad of a preacher bench. It primarily targets the brachialis, with the biceps brachii and brachioradialis assisting. Because the pad eliminates swing and momentum, it forces strict, controlled reps and is a reliable way to add size and strength to the arms.

How to do the Barbell Preacher Curl

1Set the preacher bench so the top of the pad sits just under your armpits, and load an EZ or straight barbell on the rack in front of you.
2Sit down and rest the backs of your upper arms flat against the pad, keeping your chest against the top of the support.
3Take a shoulder-width underhand grip on the bar and lift it off the rack so your arms are extended down the slope of the pad.
4Curl the bar up in a smooth arc by flexing your elbows, keeping your upper arms pinned to the pad throughout.
5Squeeze the upper-arm muscles at the top, stopping just short of the point where tension comes off the working muscles.
6Lower the bar under control back toward extension, resisting the weight on the way down.
7Stop just before your elbows lock out fully so you keep tension and avoid yanking out of the stretched position.
8Complete your reps, then guide the bar back onto the rack with control before standing up.

Form tips

Keep both upper arms flat on the pad for the whole set — letting the elbows lift turns it into a swinging curl and removes the isolation.
Use an EZ-bar if a straight bar bothers your wrists; the angled grip keeps the forearms more comfortable while still loading the same muscles.
Lower with a slow, controlled tempo (around 2–3 seconds) to make the stretched bottom portion do real work.
Pick a weight you can curl without bouncing; the preacher bench rewards strict form over heavy loading.
Have a partner hand you the bar and take it back on heavy sets so you can stay anchored to the pad.

Common mistakes

Bouncing or yanking out of the fully stretched bottom position, which strains the elbow and biceps tendons where the muscle is at its weakest and most lengthened.
Letting the elbows lift off the pad to heave the weight up, which uses the shoulders for momentum and removes tension from the upper-arm flexors.
Locking the elbows out hard at the bottom of each rep, which dumps the load onto the joint instead of keeping it on the muscle.
Using too much weight and only completing a partial range, which shortchanges both the stretch and the contraction the movement is built for.
Bending the wrists back under the bar, which shifts strain to the forearms and can cause wrist discomfort.

Frequently asked questions

What muscles does the barbell preacher curl work?

It primarily targets the brachialis, the muscle that sits beneath the biceps, with the biceps brachii and brachioradialis assisting. The preacher pad isolates these upper-arm flexors by removing swing from the shoulders and torso.

Should I use an EZ-bar or a straight barbell?

Both work the same muscles. An EZ-bar's angled grip is easier on the wrists for most people, while a straight bar puts the forearms in full supination. Choose whichever keeps your wrists comfortable.

Why shouldn't I fully straighten my arms at the bottom?

Because the bottom of the preacher curl is the most stretched and weakest position. Snapping into a full lockout and bouncing out of it strains the elbow and biceps tendons — stop just short of lockout and keep the movement controlled.

Is the barbell preacher curl good for beginners?

Yes. The pad braces your arms and prevents cheating, so it teaches strict curl form. Start light, control the lowering phase, and avoid bouncing out of the stretch.

How many sets and reps should I do?

For arm size, 3–4 sets of 8–12 controlled reps works well. Because it is an isolation move, prioritize clean range of motion over heavy weight.