Incline dumbbell curl: target muscles and how to do it

Lean back on the bench and your arms hang behind your torso. That shoulder position is the only thing separating the incline dumbbell curl from the standing curl, and it is the part the studies measured.

The incline dumbbell curl is a biceps curl done seated on a bench set at an incline, back against the pad, arms hanging behind the line of the torso. Six studies measured what that position changes in biceps activity, in where the muscle grows and in strength, and the Overload exercise library shows which incline curls members do.

Which muscles the incline dumbbell curl targets

The incline curl flexes the elbow, so it works the elbow flexors: the biceps brachii, with its long and short heads, the brachialis and the brachioradialis. The Overload library lists the biceps as the primary muscle of every incline curl.

The long head of the biceps is the only one of these muscles that also crosses the shoulder. When the arm hangs behind the torso, the shoulder is in extension and the long head starts the rep lengthened. On a preacher bench it is the reverse: the shoulder is flexed and the long head starts shortened (Oliveira et al., 2009).

What the EMG measured

Oliveira et al. (2009) recorded the activity of the biceps long head in 22 men with at least a year of strength training. Each did one rep of three dumbbell curls at 40% of their maximal isometric force: standing, incline with the trunk leaned back 50°, and preacher.

All three curls drove the biceps to at least 50% of its maximal activity. During the lift, the incline curl and the standing curl both reached up to 95% of maximal activity in the last third of the movement, with the same pattern over the whole range. The preacher curl peaked at 80% at the start of the lift, then dropped off. Activity was lower on the way down for all three.

So in this study, leaning back did not raise long-head activity above the standing curl. The authors explain why the start of the incline curl is quiet: with the arm hanging straight down, the dumbbell sits almost under the elbow and its lever arm is short. The resistance is greatest near 90° of elbow flexion. The stretched bottom of the rep is also where the load weighs least.

Where the muscle grows

Kassiano et al. (2025) took the comparison to growth. Sixty-three young women did either incline curls (n = 33) or preacher curls (n = 30), twice a week for eight weeks, with elbow flexor thickness measured at three sites along the arm.

The incline curl grew the region near the shoulder more, by 0.08 cm (95% CI 0.02 to 0.13). The preacher curl grew the region near the elbow more, by 0.10 cm (95% CI 0.04 to 0.15). Each group also gained more 3RM strength on its own exercise: 0.86 kg more on the incline curl, 1.88 kg more on the preacher curl.

Thickness was measured on the elbow flexors as a whole, so the study cannot say whether the gain near the shoulder belongs to the biceps long head or to the brachialis below it.

What training at long muscle lengths adds

The stretched-position argument comes from studies that changed the range of the curl, all on a preacher bench. Pedrosa et al. (2023) had nineteen untrained young women train one arm over the first half of the range (0 to 68°, elbow almost straight) and the other over the second half (68 to 135°), three times a week for eight weeks. The arm trained near extension grew more at 70% of humerus length, toward the elbow, and gained more 1RM over the full range. At mid-arm, both grew the same.

In thirteen trained people, Havers et al. (2025) compared the first half of the range (0 to 70°) with the full range (0 to 140°) on the preacher curl over eight weeks. The partial version had a trivial to small edge at 70% of the arm (standardized mean difference 0.10), and the full range a negligible edge on 1RM.

Nunes et al. (2020) moved the hardest point of the preacher curl instead of the range: barbell, heaviest with the elbow extended, or cable, heaviest with the elbow flexed. Over ten weeks in 35 young adults, biceps thickness grew by 8% and 7%, with no difference. The barbell group gained more strength only at 20° of elbow flexion, 39% against 30%.

These studies lengthen the biceps at the elbow, with the load heaviest there. The incline curl lengthens the long head at the shoulder, while the load is lightest at the bottom. No study read compares growth on the incline curl and the standing curl.

Mixing shoulder angles

Barakat et al. (2019) tested the shoulder angle within one session. Trained participants did nine sets of curls with the shoulder neutral, or three sets in 30° of extension, three neutral and three in 90° of flexion. Volume load did not differ, and biceps activity over the session was higher with the varied angles (95% CI 8.4 to 23.3%).

The incline curl puts the shoulder in extension and the preacher or spider curl puts it in flexion. Pairing one of each in the same week trains the long head in both shoulder positions.

How to do the incline dumbbell curl

1. Set the bench back at an incline. Oliveira et al. had the trunk leaned back 50° from vertical. The lower the bench, the further the arms hang behind the torso.
2. Sit back with your head and shoulders on the pad, a dumbbell in each hand, arms hanging straight down, palms facing forward.
3. Curl both dumbbells, or one after the other, without bringing the elbows forward. If the elbows drift ahead of the torso, the shoulder leaves extension and the rep turns into a standing curl.
4. Lower under control to a straight elbow, then start the next rep from there.

Track the incline curl load on its own: in Kassiano et al., each group gained more strength on the exercise it trained. With palms facing each other, the same setup is the incline hammer curl. The hammer curl guide covers what the neutral grip changes.

The incline curls in the Overload library

The Overload exercise library holds 897 movements. Nine curls carry "incline" in their name or are done on an incline bench, and they split into two opposite positions: back on the pad with the arms behind the torso, or chest on the pad with the arms in front.

Variant	Arm position	Secondary muscles	Member uses
Incline Dumbbell Curl	Behind the torso	None	312
Alternate Incline Dumbbell Curl	Behind the torso	Forearms	275
Incline Hammer Curls	Behind the torso	None	24
Incline Inner Biceps Curl	Behind the torso	None	2
Flexor Incline Dumbbell Curls	Behind the torso	None	0
Spider Curl	In front, chest on the pad	None	151
Standing One-Arm Dumbbell Curl Over Incline Bench	In front, arm over the pad	None	47
Dumbbell Prone Incline Curl	In front, chest on the pad	None	0
Barbell Curls Lying Against An Incline	In front, chest on the pad	None	0

The counter adds up the logged sessions in which each movement appears. It counts neither sets nor people, and a movement that comes up first in the app's search has an edge.

The two supinated dumbbell versions with the arms behind the torso total 587 uses. The standing Dumbbell Bicep Curl and Dumbbell Alternate Bicep Curl total 442. Members log the dumbbell curl more often leaning back than standing.

The neutral grip goes the other way. The incline hammer curl has 24 uses against 658 for the standing Hammer Curls.

"Incline" in a name does not say where the arm is. The four chest-on-the-pad versions, 198 uses, put the shoulder in flexion like the Preacher Curl (269 uses), which shortens the long head instead of lengthening it.

Practical recommendations

• Pick the incline curl to train the biceps with the long head lengthened at the shoulder. Expect activity close to the standing curl, not higher (Oliveira et al., 2009).
• Pair it with a preacher or spider curl in the same week. Kassiano et al. (2025) measured more growth near the shoulder with the incline curl and near the elbow with the preacher curl.
• Keep the elbows behind the torso for the whole rep. Once they move forward, the stretch at the shoulder is gone.
• Go all the way down to a straight elbow. The studies on long muscle lengths found the bottom of the curl worth keeping (Pedrosa et al., 2023, Havers et al., 2025).
• Log the incline curl as its own exercise, separate from the standing curl, since strength gains follow the version trained.
• The same arm-position logic applies to the triceps long head, which crosses the shoulder too. The guide on triceps extensions covers it.

Conclusion

The incline dumbbell curl targets the biceps, like every curl, and its one difference is the arm behind the torso, which lengthens the long head at the shoulder. Biceps activity matches the standing curl, and growth shifts toward the shoulder compared with the preacher curl. Overload members log the supinated incline versions 587 times, more than the standing dumbbell curls.

This article presents the current scientific evidence. For a personalised program, consult a health professional.