Dumbbell vs Machine Shoulder Press: Which Should You Do?

1. Dumbbell or machine: which is better for shoulder growth?

Neither, by much. When you compare the dumbbell shoulder press vs the machine, both build about the same muscle over time. A 2023 review of 13 studies found that free weights (dumbbells and barbells) and machines built about the same amount of muscle (Haugen et al., 2023).

What does change is how each one feels while you press.

• Dumbbells: nothing guides them, so your shoulders also have to keep the weights steady. Pressing with dumbbells put more work on the shoulder muscles than pressing with a barbell or a machine (Saeterbakken & Fimland, 2013; Coratella et al., 2022).
• Machine: here, "machine" means the seated shoulder press machine: you sit, push two handles overhead and pick the weight with a pin. It's not the Smith machine, where you press a barbell on rails. The handles move along a set path, so you don't have to stop the weight from drifting forward, back or to the sides like you do with dumbbells. That makes it easier to learn, and you can stop safely at any point.

How to pick:

• It's your first time: start with whichever you can press at least 8 times, light dumbbells (2 to 5 lb) or the lightest plate on the machine. If both work, start with the machine. The handles move along a set path, so the movement is easier to learn.
• You can't press the machine's lightest plate 8 times: start with dumbbells. They come as light as 2 lb, so you can start lighter than on the machine.
• Your arms wobble or your hands end up at different heights with dumbbells: go down one dumbbell size. If they still wobble, learn the movement on the machine first.
• You moved up a dumbbell and lost a lot of reps: that's normal. Dumbbells usually go up 5 lb at a time, and going from 30 lb to 35 lb is about 17% heavier in one step. To build reps with your current pair before moving up, read How to Progress When You Can't Add Weight on Dumbbells.
• You train at home, or the machine is always taken: use dumbbells. Your shoulders will grow just as well.

• Dumbbell Shoulder Press
• Shoulder Press Machine

2. How many sets and reps should you do?

You don't need both. Doing one press consistently is enough to build your shoulders.

• Use a weight you can press at least 8 times without leaning back.
• Move up once you hit the highest rep number in the table on every set. For 3 x 8-12, that means 12 reps on all three sets. Next workout, go up one plate on the machine, or to the next pair of dumbbells.
• Log the dumbbell and machine presses separately. The weights don't match, because a machine's numbers vary from brand to brand.

If you want to know more about adding weight over time, read Progressive Overload Is the Only Variable That Actually Guarantees Muscle Growth.

3. Going further: should you press sitting or standing?

If you're a beginner, sit. You can press about 10% more with dumbbells seated than standing, but standing puts more work on the side and back of your shoulders and on your abs (Saeterbakken & Fimland, 2012; Saeterbakken & Fimland, 2013).

So neither is wrong. Seated lets you go heavier with your back held in place. Standing works more muscles but asks for more balance. If your lower back arches a lot when you press standing, sit down and lean your back against the bench.

• Dumbbell Shoulder Press
• Standing Dumbbell Shoulder Press

Frequently asked questions