Dumbbell Prone Incline Curl

What the prone incline curl actually trains

A prone incline curl is a biceps isolation exercise performed lying chest down on an incline bench, with both arms hanging straight below the shoulders while you curl a pair of dumbbells.

The biceps brachii flexes the elbow and supinates the forearm, the brachialis works underneath it regardless of grip, and the brachioradialis contributes as the weight increases.

The bench does one thing and does it well. Lying face down with your chest supported removes the hip drive, the backwards lean and the shoulder swing that creep into standing curls. There is nowhere for the momentum to come from, so the arms have to do the work.

It is worth correcting a claim that follows this exercise around. It is often described as the ultimate stretch position for the long head of the biceps. It is not. The long head crosses the shoulder as well as the elbow, so it is lengthened when the upper arm sits behind the torso. Here the arms hang below the shoulders, which is a neutral shoulder position at best. The exercise that genuinely loads the stretch is the supine incline curl, where the arms fall behind you.

What this actually gives you is a strict curl loaded hardest through the middle of the range, with useful tension persisting as you approach full flexion. That is a perfectly reasonable thing to train. It is just not the thing the marketing says.

The evidence increasingly favours training muscles at long lengths. Pedrosa and colleagues found partial repetitions at long muscle lengths produced better hypertrophy than short length work, and Maeo and colleagues found the same pattern in the hamstrings. This exercise sits on the other side of that argument, which is why it works better as a supplement than as a foundation.

Setting up and executing

Set an incline bench to roughly forty five degrees. Steeper is usually better, since a shallow bench leaves the dumbbells hitting the floor before your elbows straighten.

Take a dumbbell in each hand and lie chest down against the pad, with your chin or forehead resting lightly on the top.

Let both arms hang straight down below the shoulders with the palms facing forward. This hanging position is the start of every rep.

Curl both dumbbells up towards the shoulders while the upper arms stay vertical. Squeeze for a beat near full flexion.

Lower over about three seconds until the elbows are completely straight, keeping your chest in contact with the pad the whole time, then curl again without a bounce.

The mistakes that cost you the most

Swinging the upper arms forward is the fault that undoes the setup. Because you cannot rock the torso, the only cheat left is shoulder flexion, and the elbows drifting forwards is exactly that. If the upper arms are not hanging vertically at the top of a rep, the set is over.

Peeling the chest off the pad is the other escape route. It usually appears in the last two or three reps and it converts a strict exercise into a clumsy standing one.

Expecting a stretch leads to disappointment and to bad exercise selection. If a lengthened position is what you are after, use a supine incline curl instead, where the arm actually sits behind the body.

Setting the bench too low is a mechanical problem rather than a technique one. If the dumbbells reach the floor before your elbows are straight, you are training a partial range for no reason, and Pallares and colleagues found full range work outperformed partial range work for strength and hypertrophy.

And going heavy simply reintroduces every cheat the bench removed.

Sets, reps and rest by goal

Moderate to high reps, light loads, unremarkable rest periods.

For muscle gain, three sets of ten to fifteen with a minute. For strength, three sets of eight to twelve with ninety seconds. In a fat loss phase, three sets of twelve to twenty with forty five seconds.

Take three seconds over the lowering phase. Roig and colleagues found eccentric training produced greater strength gains than concentric training, and on an exercise this light the descent is where much of the useful work lives.

Progress by reps first and by dumbbell second. Because the position is so strict, the jump to the next pair of dumbbells is often ten per cent or more of your working load, so expect to hold a weight for several weeks.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy, and this is a low fatigue way to add two or three quality biceps sets.

Refalo and colleagues found stopping a rep or two short of failure produces comparable growth to going all the way. Here the natural stopping point is the rep where your elbows start travelling, which usually arrives first anyway.

Where it fits in your split

Late in a pulling or arm session, after the heavier work.

On push, pull and legs it belongs at the end of pull day. On a bro split it follows the heavier curling on arm day. On an upper and lower split it works as a finisher in either upper session. On a full body programme it is rarely worth occupying an incline bench for.

The honest programming advice is that this is a second or third biceps exercise, not a first. Pair it with something that loads the stretched position, such as a supine incline curl, and you have covered both ends of the range with two movements.

The frequency guidance in the seed data is low for a reason. This is a slow, fiddly exercise that requires a free adjustable bench, and its stimulus is not different enough from a preacher or spider curl to justify doing all three.

Once a week is plenty if you have other biceps work in the programme, which you almost certainly do given that every row and chin-up loads the elbow flexors.

Variations worth knowing

The spider curl is the same movement on a steeper bench or over the vertical side of a preacher pad, and for practical purposes it is the same exercise.

The preacher curl supports the upper arms on a pad instead of hanging them, which allows a barbell, more load and a seated position.

The incline dumbbell curl, lying face up, is the movement that genuinely loads the stretched position and is the better partner for this rather than a competitor.

A prone incline hammer curl keeps a neutral grip and moves more of the work to brachialis and brachioradialis, which is worth doing for arm thickness.

The cable spider curl uses a low pulley and keeps tension high near full flexion, where dumbbells fade.

And the concentration curl is the single arm equivalent, with a similar strictness and a similar resistance profile.

What the evidence says

Marcolin and colleagues compared curl variants and found the balance of activity between the biceps brachii and the brachioradialis shifts with arm position and grip, supporting the view that where the upper arm sits is the variable that distinguishes one curl from another.

Pedrosa and colleagues found partial repetitions performed at long muscle lengths produced better hypertrophy outcomes than the same work at short lengths, which is the strongest argument for pairing this exercise with one that loads the stretch.

Maeo and colleagues found greater hamstring hypertrophy after training at long muscle lengths compared with short ones, which is the same principle appearing in a different muscle.

Pallares and colleagues found full range training beat partial range training for strength and hypertrophy, supporting a bench angle steep enough that the elbows can straighten fully.

Roig and colleagues found eccentric training produced greater strength gains than concentric training, which is why the three second descent is worth the discipline.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy, and Refalo and colleagues found sets stopped short of failure grow muscle comparably to sets taken to it.

Common questions

Does this really stretch the long head?

No. The long head is lengthened when the upper arm is behind the torso, and here the arms hang below the shoulders. If you want a loaded stretch, lie face up on an incline bench and let the dumbbells fall behind you instead.

Is it different from a spider curl?

Barely. A spider curl uses a steeper bench or a preacher pad and the arms hang slightly more vertically, but the position, the strictness and the resistance profile are the same. Pick one and use the equipment your gym actually has free.

What bench angle should I use?

Around forty five degrees or steeper. The requirement is simply that your arms can hang fully straight without the dumbbells touching the floor, since a shortened range is a wasted range.

Why can I barely lift anything?

Because the bench has removed the hip drive, the backwards lean and most of the shoulder involvement. What is left is your actual elbow flexion strength, which is always lower than what a standing curl suggests.

Is it worth doing at all?

As a second or third curl, yes. As your main biceps exercise, no, because it loads the position the evidence is least enthusiastic about. Total weekly hard sets matter far more than which of the fifteen available curls you choose.