What Do Preacher Curls Work: Complete Guide to Target Muscles and Benefits

Preacher curls are a go-to move for building bigger, stronger arms. Whether you’re using a preacher curl bench, dumbbells, or a cable machine setup, this exercise is designed to isolate your biceps and eliminate momentum.

If you’ve ever caught yourself wondering which muscles this exercise really targets, you’re not alone.

Preacher curls mainly hit your biceps brachii—especially the long head—while also getting help from muscles like the brachialis and brachioradialis. The way the preacher bench is set up, you can’t cheat by swinging the weight, so your arms have to do all the heavy lifting.

Knowing exactly how preacher curls work your arms can really help you dial in your training. Here’s a closer look at which muscles get involved and why preacher curls might just be worth adding to your routine.

Muscular Focus of Preacher Curls

Primary Muscles Activated

The biceps brachii is the star here. It’s got two parts—the long head and the short head. The preacher curl really stretches out the long head, which runs along the outside of your upper arm.

Your biceps brachii bends your elbow against the weight. Thanks to the bench’s angle, your arms stay in front of your body, giving the long head more of a stretch than regular curls.

Since you can’t use momentum or body swing, your biceps are left to do the work—no shortcuts here.

Secondary Muscle Engagement

The brachialis muscle, tucked under your biceps, helps with elbow flexion. It gets a good workout during preacher curls.

Your brachioradialis, running from elbow to wrist, also helps flex your elbow.

When you use an underhand grip, the supinator muscles in your forearm also get involved to help rotate and support the lift.

Stabilizing Muscle Groups

Your forearm flexors help you maintain a solid grip on the weight, while your anterior deltoid helps stabilize your upper arm against the bench.

Your core also helps keep your torso steady, even though it’s not the main focus here.

Benefits of Preacher Curls

Enhanced Muscle Isolation

The preacher bench prevents you from using momentum, so your biceps stay loaded from start to finish without relying on momentum.

Strength and Hypertrophy Potential

Because the movement is so controlled, it’s easier to gradually increase the weight over time.

Impact on Arm Aesthetics

Preacher curls emphasize the lower portion of the biceps and the brachialis, contributing to fuller, more defined arms.

What Equipment Is Best for Preacher Curls?

While preacher curls are traditionally performed on a preacher bench, you can still do them a few different ways depending on what equipment you have:

• Dumbbells: Great for correcting muscle imbalances and improving control

• Barbell or EZ Bar: Ideal for heavier loading and strength progression

• Cable Machines: Provide constant tension throughout the movement

• Smith Machine Setups: Offer added stability and safety, especially for beginners or solo training

For home gym users, an all-in-one setup that combines a Smith machine with a cable system makes this much easier to do at home. You get more control, smoother resistance, and the ability to switch between exercises without changing machines.

Example: Mikolo All-in-One Smith Machine

Preacher Curls vs Regular Curls

Unlike regular bicep curls, preacher curls eliminate momentum and reduce shoulder involvement, making them more effective for strict isolation.

Regular curls allow heavier weights and more natural movement, while preacher curls focus on control and muscle tension.

FAQ

Are preacher curls better than regular curls?

They’re better for isolation, while regular curls are better for overall strength and functional movement.

Can preacher curls build bigger biceps?

Yes. They’re highly effective for hypertrophy when combined with progressive overload.

Should beginners do preacher curls?

Yes, especially since the setup helps enforce proper form and reduces cheating.

Can you do preacher curls at home?

Absolutely. With the right equipment setup—like a bench, dumbbells, or a cable/Smith machine—you can perform effective preacher-style curls at home.

Final Tip: If you’re training at home, choosing versatile equipment can make exercises like preacher curls easier, safer, and more effective to perform consistently.