Arnold Press: How to Do It, Muscles Worked and Benefits

The Arnold press is a dumbbell shoulder press with a twist, quite literally. Named after Arnold Schwarzenegger, who popularised it, it starts with the dumbbells at chin height and your palms facing you, then rotates your hands outward as you press overhead. That rotation is the whole trick: it works the front and side of your shoulder in the same rep and takes the joint through a longer range than a standard press. The result is a movement that builds rounder, more complete shoulders. Here is how to do it properly, the muscles it works, and how to get the most from it.

How to do an Arnold press

You need a pair of dumbbells and, ideally, a bench with an upright back for support. A pair of adjustable dumbbells is perfect here because you will want to fine-tune the weight.

1. Set up. Sit on a bench with the backrest upright and your feet flat on the floor. Hold a dumbbell in each hand at about chin or upper-chest height, elbows tucked in front of you and palms facing back towards your face, as if you are at the top of a bicep curl.
2. Brace. Sit tall, pull your shoulder blades down and back, and tighten your core so your lower back does not arch as you press.
3. Rotate and press. As you push the dumbbells up, rotate your wrists outward so your palms turn to face forward. The rotation and the press should happen together in one smooth motion.
4. Finish overhead. Press until your arms are almost straight and the dumbbells are above your shoulders, palms facing forward. Keep a slight bend in the elbows at the top rather than locking out hard.
5. Reverse it. Lower under control, rotating your palms back towards your face as the dumbbells come down, until you return to the start position at chin height. That is one rep.

Muscles worked

The Arnold press is a shoulder exercise first and foremost, and the rotation is what lets it hit more of the shoulder than a plain press.

• Anterior (front) deltoid. The front of your shoulder does a large share of the pressing work, driving the dumbbells up and overhead. Surface EMG research on overhead pressing shows high activity across the deltoids during the movement (EMG study of the overhead press).
• Lateral (side) deltoid. The rotation brings the side head into play more than a fixed-grip press does. The middle deltoid is the muscle that lifts your arm out to the side and builds shoulder width (the middle deltoid drives abduction from roughly 15 to 100 degrees).
• Posterior (rear) deltoid. The starting position, with palms facing in and elbows forward, gives the rear head a little more involvement than a standard press, which is why the Arnold press is prized for all-round shoulder shape.
• Triceps. The muscles on the back of your upper arm straighten the elbow to finish each rep overhead.
• Upper chest, upper back and core. Your upper pecs assist at the bottom, your traps and upper back stabilise the shoulder blades, and your core keeps your torso upright so the shoulders do the lifting.

Benefits

• It builds well-rounded shoulders. Because the rotation recruits the front and side heads in one rep, the Arnold press develops the shoulder more completely than a press that only faces one direction. That is what gives shoulders their capped, rounded look.
• It trains a longer range of motion. Starting at chin height with palms in means the dumbbells travel further than in a standard press, and training through a full range tends to pay off for muscle growth.
• It improves shoulder control and mobility. The controlled rotation under a light load teaches your shoulder to move smoothly through internal and external rotation, which carries over to other lifts and daily reaching.
• It needs very little kit. A pair of dumbbells and a bench is all it takes, which makes it ideal for home training. The NHS recommends muscle-strengthening work for all the major muscle groups on at least two days a week, and shoulder pressing is an efficient way to cover the upper body.

Common mistakes

Going too heavy. This is the big one. The rotating path puts the shoulder in a less stable position than a straight press, so a weight you can grind out on a normal press will be too much here. Drop the load and keep the movement smooth.

Rotating too early or too late. If you flip your palms forward before the dumbbells clear your head, you turn it into a normal press with a wasted wiggle at the start. The rotation should be gradual and finish as your arms reach the top.

Arching the lower back. Pushing heavy dumbbells overhead tempts you to lean back and turn it into an incline press. Brace your core, keep your ribs down and, if you cannot stop arching, lower the weight.

Flaring the elbows out at the bottom. Let your elbows drift too wide too early and you lose the front-loaded start that makes the exercise work. Keep them tucked in front of you at chin height, then let them travel outward naturally as you press and rotate.

Shrugging the shoulders up. If your shoulders ride up towards your ears, your upper traps take over. Keep your shoulder blades pulled down and back throughout so the deltoids stay in charge.

Variations

• Seated Arnold press. The standard version, done on a bench with back support. The most controlled option and the best place to learn the movement.
• Standing Arnold press. Done on your feet for an added core and balance challenge. Use a lighter weight, as it is easier to swing and cheat.
• Single-arm Arnold press. Press one dumbbell at a time. This lets you focus on smooth rotation on each side and stops a stronger shoulder taking over, and it hammers your core to resist the uneven load.
• Half-kneeling Arnold press. Drop to one knee to remove your legs from the equation and force your core and hips to stabilise. Good for ironing out side-to-side differences.
• Neutral-grip press. If the rotation bothers your shoulder, keep your palms facing each other and press straight up. It is gentler on the joint while still training the shoulders. Our dumbbell shoulder press guide covers the standard press in full.

Sets and reps

A simple plan that works for most people:

• Muscle and shape: 3 to 4 sets of 8 to 12 reps, 2 times a week. Rest 60 to 90 seconds.
• Endurance or a finisher: 2 to 3 sets of 12 to 15 reps with a lighter weight, rest 45 to 60 seconds.
• Learning the move: 3 sets of 10 slow reps with a very light weight, focusing only on the rotation and staying upright.

Because the Arnold press is a shoulder-detail exercise rather than a max-strength one, keep the reps a touch higher and the weight controlled. Slot it in after a heavier press or as part of an upper-body day. Add a small amount of weight only when every rep of your top set stays smooth and controlled.

Recommended reads

1. The best adjustable dumbbells in the UK
2. Dumbbell shoulder press: how to do it
3. Overhead press: technique and muscles worked
4. Lateral raises: build wider shoulders
5. The best weight bench in the UK