Barbell Concentration Curls

Setting up the seated position

The barbell concentration curl requires careful seated setup because the upper arms have to brace against the thighs without sliding. Walk through each phase before adding load.

1. Seated position

Sit on a flat bench with feet wider than shoulder width. Lean forward slightly so the chest sits over the thighs. Hold the barbell in a supinated grip slightly narrower than shoulder width. Rest the back of the upper arms against the inside of the thighs near the knees.

2. Arm position

The upper arms should sit braced against the inner thighs. The forearms hang straight down with the barbell at full arm extension. The angle of the upper arm is roughly 45 degrees from vertical. This braced position is what makes the concentration curl a true isolation exercise.

3. The curl

Curl the barbell up by flexing the elbows. The upper arms stay braced against the thighs throughout. The barbell travels in an arc up toward the chest. Squeeze the biceps hard at the top of the rep for a one second peak contraction. The forearms come close to vertical at the top.

4. The descent

Lower the barbell under control over two seconds. The arms fully straighten at the bottom but the upper arms stay braced against the thighs. Do not let the barbell drop or the upper arms come off the thighs. The braced position is what isolates the biceps.

5. The reset

Between reps reset the brace by squeezing the upper arms slightly into the thighs. This pre-tension keeps the upper arms locked in position for the next rep. If the upper arms slide off the thighs during the set, the load is too heavy or the seated position is too wide.

What barbell concentration curls train

The barbell concentration curl is a near pure biceps isolation exercise. The braced upper arms remove the shoulder from the equation so the biceps and brachialis do all the work.

Biceps brachii

Primary mover. The braced upper arm position lets the biceps work without anterior delt help. EMG studies show concentration curls produce some of the highest peak biceps activation of any curl variation, particularly the long head which contributes most to the visible biceps peak.

Brachialis

The brachialis sits beneath the biceps and contributes to elbow flexion. The supinated grip places the biceps in a strong position but the brachialis still does meaningful work, especially in the bottom range of the curl before the biceps takes over.

Brachioradialis

The most prominent forearm muscle. It assists with elbow flexion and grip. The supinated grip reduces brachioradialis involvement compared to neutral or pronated curls but it still works isometrically to hold the bar.

Forearm flexors

The forearm flexors hold the barbell against gravity throughout the rep. Grip becomes a meaningful factor in concentration curls because the seated position means the wrist has to hold the bar in a slightly less mechanically advantageous position than a standing curl.

Five errors on barbell concentration curls

The barbell concentration curl has subtle errors that turn it from an isolation exercise into a sloppy compound. The most common failures relate to elbow position and trunk movement.

Upper arms sliding off the thighs

If the upper arms come off the thighs during the rep the lift fails as a concentration curl. The braced position is what isolates the biceps. If the arms keep sliding off, the load is too heavy or the seated stance is too wide. Reduce load and narrow the stance.

Rocking the trunk

Using trunk extension to help the curl moves the load to momentum. The trunk should stay rigid throughout the set. If trunk movement is needed to complete reps the weight is too heavy. Drop ten percent.

Partial range of motion

Stopping the descent before full arm extension reduces the range of motion. The biceps does its most productive work through the full stretched to shortened range. Allow the arms to fully straighten at the bottom of every rep, even though the upper arms stay braced.

Wrong barbell type

A standard straight barbell can stress the wrists in the supinated concentration curl position. An EZ bar with the inner curve is more wrist friendly. If your gym only has a straight barbell, narrow the grip slightly to reduce wrist strain.

Going too heavy

Most lifters use concentration curl weights based on barbell curl strength. The concentration position is mechanically weaker so productive working weights are typically 60 to 70 percent of standing barbell curl weight. Start lighter than you think and build up.

Sets, reps and where concentration curls fit

Barbell concentration curls are an accessory exercise. They work as a peak development finisher after heavier compound curls or as a focused biceps exercise on dedicated arm days.

Hypertrophy: 8 to 12 reps

The productive range. 3 to 4 sets of 8 to 12 reps at moderate loads. Stop 1 to 2 reps short of failure. The braced position and controlled tempo are what produce hypertrophy on this exercise, not heavy load. Strict form throughout.

Peak development: 12 to 15 reps

Higher rep barbell concentration curls work as a peak development finisher. 2 to 3 sets at the end of an arms session at light to moderate loads. The longer time under tension at lighter loads produces blood flow and bicep peak development.

Strength is rarely the goal

Concentration curls are not a strength exercise. The braced position and isolation nature limit loading potential. Heavier work should go on barbell curls, EZ bar curls or other compound bicep exercises. Keep concentration curls in the hypertrophy and accessory categories.

Frequency

2 to 3 sessions per week is well tolerated. Concentration curls recover quickly because the loads are moderate and the joint stress is low. Many balanced bicep programmes include them as a finisher in every arms session.

Pairing

Pair concentration curls with hammer curls or cable curls for a complete bicep finisher. They also work well as supersets with tricep extension variations for full arm finishers at the end of upper body sessions.

More on bicep training

For the dumbbell unilateral version, our Concentration curls guide covers single arm focused work. Barbell preacher curls are the alternative seated isolation curl. And the Barbell curls page covers the heavier standing compound curl.