Build Your Biceps with Concentration Curls

Few exercises come to mind more readily when you think of bodybuilding than the biceps curl. It conjures images of Arnold Schwarzenegger in the iconic documentary Pumping Iron, hoisting a dumbbell in the heart of a no-frills gym, surrounded by mirrors, benches, and racks.

Among the many versions of the exercise, one has outpaced the competition when it comes to isolating the biceps: the concentration curl. Even if you’re not training to be the next Mr. or Ms. Olympia, concentration curls still deserve a spot in your rotation (not to mention, they give you a serious pump). Here's everything you need to add them to your program the right way.

What Is a Concentration Curl?

A concentration curl is a single-arm biceps exercise typically performed with a dumbbell while seated. Its value is in the name (“concentration”), as it requires isolating the biceps by bracing your upper arm against your inner thigh. The focus is less on how much weight you can move and more on how well you can engage the muscle and control each rep.

Who Should Do Concentration Curls

Whether you’re a recreational lifter or a competitive bodybuilder, concentration curls can deliver. Given their isolation focus, they're an ideal fit if you have hypertrophy- or physique-related goals. They’re also worthwhile if you prioritize mind-muscle connection in your training.

For that reason, they're not the best option if you’re chasing pure strength. Instead, you can opt for movements more conducive to maximal loading, such as barbell curls.

Concentration Curl Muscles Worked and Benefits

Concentration curls are all about the arms. They primarily work the biceps brachii, building the muscle’s “peak,” or its vertical height when flexed. They also engage the brachialis, which sits under and pushes the biceps up as it grows, boosting arm width and height. Additionally, they train the brachioradialis, contributing to greater grip strength and better proportionality between the forearm and upper arm.

In terms of effectiveness, they pay off big time. A study by the American Council on Exercise (ACE) found that concentration curls activated the biceps significantly more than other popular exercises targeting the muscle, including barbell curls, cable curls, and chin-ups. Not only that, but they engaged the anterior deltoid less than most of the other movements tested, highlighting their isolation advantage.

How to Do Concentration Curls

Dialing in your concentration curl form and setup is crucial to getting the most out of the exercise. While several variations exist, the seated dumbbell concentration curl is the classic version. Here's how to do it.

Take a seat: Sit on a bench with a dumbbell in one hand. Position your legs wider than shoulder-width and plant your feet firmly on the ground. For added support, you can rest the outside of the leg on your working side against the bench.

Brace your arm: Lean forward slightly — engaging your core and being mindful not to round your shoulders — and anchor the back of your upper arm (right around the triceps) against your inner thigh on the same side. Make sure your hand doesn't touch the ground when your arm is fully extended.

Curl and squeeze: From the extended position, curl the dumbbell in a controlled arc, maintaining contact between your arm and thigh, inhaling as you bring the weight up. Once you reach the top, squeeze the biceps hard, feeling the muscle fully contract.

Control the descent: Lower the dumbbell slowly and under control, exhaling on the way down. Stop at the bottom once you’re back to a full stretch and repeat for the prescribed number of repetitions.

Concentration Curl Variations

If your setup doesn't include a bench or dumbbells — or you simply want to mix up your training — you can stray from the traditional seated version and still reap the benefits with these variations.

Standing Concentration Curl

Assume a wide stance, hinge at the waist, and brace your upper arm against your inner thigh, just like with the seated version. Keep your core braced and feet actively pressing into the ground, as this variation demands more of your posterior chain.

Cable Concentration Curl

If your gym has a functional trainer or cable machine, you can use that in place of a dumbbell. One of the benefits is that you can change the load quickly, unless you have adjustable dumbbells or a collection of dumbbells. Set the cable pulley close to the floor with a D-handle, and elevate the foot on your working side on a bench or box. Position yourself far enough away from the pulley to maintain cable tension throughout the movement. With the same bracing approach as the dumbbell version, curl using a supinated grip.

Landmine Concentration Curl

Pairing a barbell with a landmine attachment also works for performing concentration curls. And face it: You look undeniably cool whenever you do a landmine workout. To account for the low-anchor point, set up in a half-kneeling position with the foot on your working side facing the attachment. Hold onto the barbell sleeve and curl, following the landmine’s circular path and keeping your pinky turned upward. Because the sleeve is thicker than dumbbells or D-handles, this variation poses a greater challenge for your grip and forearms.

Concentration Curl Common Mistakes

No matter the variation, it helps to know the common mistakes you can make with concentration curls to ward off bad habits and get the most out of them.

Rounding the shoulders: It can be easy to hunch and bring the shoulders forward, especially as fatigue sets in, but doing so shifts tension away from the biceps. Keep your chest up, shoulders pulled back and down, and core braced.

Going too heavy: The concentration curl is a mind-muscle, isolation-focused exercise. It’s not about max load but rather how well you can command every rep. Leave the ego at the door and go for quality over quantity.

Using momentum: This often results from using a weight that’s too heavy, forcing you to swing your torso or drive your hips to heave it up. Aim for a steady, even tempo as you curl, squeeze at the top, and return to the start position, dropping the load if you feel your form start to break down.

Cutting reps short: Both ends of each rep matter. The full stretch at the bottom is where a lot of the growth happens, and skipping the squeeze at the top means leaving peak contraction on the table. Go through the full range of motion every time.

Moving the arm or leg: Your upper arm should remain pinned against your inner thigh rep after rep, set after set. Don't let your elbow drift away from your leg to help get the weight up. On the flip side, avoid pushing your leg too forcefully into your arm, which creates excessive movement that shifts tension away from the biceps. Both should act as a static point of contact, not a means of assistance. 

Concentration Curl Alternatives

As great as the concentration curl is, working other curls into your training can provide new stimulus and lead to better progress over the long haul. Pick and choose which are best suited to your goals and equipment.

Standard Dumbbell Curls

Seated or standing, dumbbell curls are a solid option when you want to load both arms and move more total weight. You can curl the dumbbells simultaneously or alternate to extend time under tension.

Incline Dumbbell Curls

Because your arms hang behind your torso throughout the movement, incline dumbbell curls offer another way to stretch the biceps under load and avoid using momentum to grind through reps. No cheating!

Preacher Curls

Bracing your arm against a preacher pad attachment or bench rather than your thigh, preacher curls take a similar isolation approach to concentration curls. By loading the muscle in the lengthened position at the bottom of each rep, they help develop your biceps — especially the lower part near the elbow crease.

Hammer Curls

If a supinated grip causes elbow pain or discomfort, hammer curls let you train the biceps while showing your brachialis and forearms some love. You can do them seated or standing, curling both dumbbells simultaneously or alternating sides.

Barbell Curls

The main benefit of barbell curls is that you can move more total load, which is a major draw if you prioritize raw strength. You can also use a dedicated curl bar to vary your grip and take stress off your wrist and elbows.

Read more: Choosing the Right Barbell: Different Types of Barbells for Different Types of Lifts

Programming Concentration Curls

Concentration curls are best treated as an accessory exercise that comes after compound lifts and any heavier movements targeting the biceps, such as chin-ups.

Start with 3 sets of 8 to 12 reps per arm twice per week, leaving 1 to 3 reps in reserve on your last set. Gradually increase the weight as you get stronger, and bump up the volume by doing more reps or tacking on additional sets (for a total of 4 to 5) each week.

Home in on fully controlling the eccentric portion of the movement and keeping a steady tempo, resting about 30 seconds between sides and 60 seconds between sets.

For a spicy arms finisher, pair it with a triceps exercise, such as dumbbell skull crushers.

Read more: The 8 Best Tricep Dumbbell Exercises for Strength and Size, CPT Approved

Takeaway

When it comes to building the biceps, you’ll be hard-pressed to find a more worthy addition to your program than the concentration curl. With its focus on isolation and control, it’s one of the most effective exercises for achieving your hypertrophy goals and developing mind-muscle connection.

FAQs

Are concentration curls good for beginners?

Yes, concentration curls are highly valuable for beginners. By isolating the biceps in a seated, braced position, they’re a low-risk way to sharpen your curl form and control before progressing to variations that require more strength and coordination.

What muscles do concentration curls work?

Concentration curls primarily target the biceps brachii, the main muscle along the front of the upper arm. They also engage the brachialis, which lies beneath the biceps, and the brachioradialis on the outer side of the forearm.

Do concentration curls build your biceps peak?

While peak shape and height are largely determined by genetics, concentration curls can meaningfully build the short head of the biceps, adding visible size and roundness to your arm.

What are the benefits of concentration curls compared to other biceps exercises?

Concentration curls have been shown to isolate the biceps brachii better than other biceps exercises, including barbell curls, preacher curls, and chin-ups. Because they require a bent-over position where you brace your arm against your inner thigh, they remove assistance from your shoulders and back. Although other curl variations are better for absolute strength and progressive overload, concentration curls win out for biceps isolation and peak contraction. If you have hypertrophy-related goals, they’re a must-add to your program.

What weight should you use for concentration curls?

Go lighter than you would for a standard curl, choosing a weight where the final 2 to 3 reps of an 8- to 12-rep set are challenging but don’t compromise form. If you need to use momentum or excessively shift your arm or leg to bring the weight up, you’ve gone too heavy. Only increase the load or volume once you can maintain a controlled tempo and full range of motion across every rep.