What muscles does the single-arm dumbbell shoulder press work?

The main muscle is the front deltoid, helped by the side deltoid, the triceps and the upper trapezius near the top of the press. What sets it apart from the two-arm version is the trunk: the obliques and the deep back muscles on the opposite side work to keep you from leaning toward the dumbbell.

Why press with one arm instead of two dumbbells?

With one dumbbell the load sits off-center, so the trunk has to brace against tipping sideways, something the two-arm press never asks for. It also shows whether one shoulder presses worse than the other, because each side does its reps without help. When the goal is simply to move more weight overhead, the two-dumbbell press is the more efficient choice.

Is it better standing or kneeling?

Half-kneeling, with the knee of the pressing side on the floor, is the more demanding version for the core because the base is smaller and the legs cannot help. Standing allows a bit more load and looks more like an athletic movement. Many coaches start clients in the half-kneeling position to learn to keep the trunk still, then move them to standing.

How much weight should a beginner use on the single-arm shoulder press?

A common guideline is to pick a dumbbell you can press for 8 to 12 reps per arm without leaning or driving with the legs. That is usually well under half of what you would use on the two-dumbbell press, because the trunk gives out before the shoulder does. Increase the load once your weaker side completes every rep cleanly.

Single-Arm Dumbbell Shoulder Press

The single-arm dumbbell shoulder press is a one-arm overhead press, standing or kneeling, that works the front deltoid while the core resists the trunk tipping toward the loaded side.

SHOULDERS · PUSH

Single-Arm Dumbbell Shoulder Press: how the movement is executed

How it is executed

Hold a single dumbbell at shoulder height with your palm facing forward, standing or kneeling tall with your core braced.
Keep your free hand on your hip or out for balance and avoid leaning to the loaded side.
Press the dumbbell straight overhead until your arm is fully extended, keeping your wrist stacked over your elbow.
Lower it under control back to shoulder level, resisting the rotation through your trunk before switching sides.

Muscles worked: Shoulders
Primary muscle: Front delt
Equipment: Dumbbell
Movement pattern: Push
Difficulty: Intermediate
What it is for: StrengthHypertrophy

Common mistakes

Leaning away from the dumbbell. It is the typical compensation when the load is too high: the body moves away from the weight so it does not have to stabilize it. Keep the ribs stacked over the hips and the shoulders level; if you cannot, lower the load.
Driving with the legs to start the rep. That momentum turns the press into a push press and takes the hardest part of the range away from the deltoid. Start every rep from the shoulder, with the knees still.
Letting the dumbbell drift out or forward. Once the path stops being vertical the shoulder works in a strained position and the wrist is no longer over the elbow. Press straight up, with the dumbbell over the shoulder and the wrist stacked over the elbow.

Frequently asked questions

What muscles does the single-arm dumbbell shoulder press work?: The main muscle is the front deltoid, helped by the side deltoid, the triceps and the upper trapezius near the top of the press. What sets it apart from the two-arm version is the trunk: the obliques and the deep back muscles on the opposite side work to keep you from leaning toward the dumbbell.
Why press with one arm instead of two dumbbells?: With one dumbbell the load sits off-center, so the trunk has to brace against tipping sideways, something the two-arm press never asks for. It also shows whether one shoulder presses worse than the other, because each side does its reps without help. When the goal is simply to move more weight overhead, the two-dumbbell press is the more efficient choice.
Is it better standing or kneeling?: Half-kneeling, with the knee of the pressing side on the floor, is the more demanding version for the core because the base is smaller and the legs cannot help. Standing allows a bit more load and looks more like an athletic movement. Many coaches start clients in the half-kneeling position to learn to keep the trunk still, then move them to standing.
How much weight should a beginner use on the single-arm shoulder press?: A common guideline is to pick a dumbbell you can press for 8 to 12 reps per arm without leaning or driving with the legs. That is usually well under half of what you would use on the two-dumbbell press, because the trunk gives out before the shoulder does. Increase the load once your weaker side completes every rep cleanly.

Variations and substitutions

Arnold PressDumbbell Machine Shoulder PressMachine Landmine PressBarbell Seated Band Shoulder PressResistance band Barbell Shoulder PressBarbell Dumbbell Shoulder PressDumbbell Smith Machine Shoulder PressSmith machine Seated Behind-the-Neck Barbell PressBarbell

Shoulders exercises Dumbbell exercises Estimated 1RM calculator Back to the library

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Effective setAn effective set is a working set taken close enough to failure to count toward training volume, in practice within the final three or four reps.PeriodizationPeriodization is organizing training into blocks with different goals and loads over time, so an athlete arrives at a given moment in the best possible state...Training volume calculatorHow many weekly sets a muscle gets

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Single-Arm Dumbbell Shoulder Press

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