Machine Single-Arm Seated Row

What the machine single-arm seated row actually trains

A machine single-arm seated row is a horizontal pulling movement performed on a chest supported row machine, pulling one handle back towards your side while the other arm rests.

The latissimus dorsi and teres major bring the upper arm back towards the torso. The rhomboids and middle trapezius retract the shoulder blade at the finish. The posterior deltoid contributes as the elbow passes behind the body, and the biceps and forearm flexors work throughout.

This is a deliberately unglamorous exercise, and that is its argument.

The machine handles everything except the pull. There is no bar path to control, no torso position to hold, no lower back involvement and no setup beyond a seat and a pin. Fenwick and colleagues compared rowing exercises and found trunk demands and spine loading varied substantially between them; a chest supported machine sits at the bottom of that range.

Doing it one arm at a time adds two things.

The first is range. With one hand the shoulder can travel fully forward around the ribcage at the front, and the elbow can pull well past your side at the back. A two handed row is limited by your own torso.

The second is that a weaker side cannot hide. Speirs and colleagues compared unilateral and bilateral training and found comparable strength adaptations, and Liao and colleagues' meta-analysis of unilateral versus bilateral training reached broadly similar conclusions. Unilateral work is not superior in itself. What it does is make an imbalance visible and then fixable, which no bilateral movement can do.

What it is not is a different exercise from the other rows in your programme. Grip, angle and machine change emphasis by degrees. Lehman and colleagues found meaningful differences in latissimus activation between traditional pulling exercises, but differences of degree are what they are. Choose based on what your gym has and what you can progress on.

Setting up and executing

Adjust the seat so the handles sit at roughly lower chest height when you are seated. Too high and the pull becomes an upper back movement; too low and you crowd your ribs.

Set the chest pad so your arms can extend fully forward without the machine blocking them.

Sit with your chest against the pad and your feet flat. Take one handle and leave the other arm resting.

Let the working arm extend fully forward and allow the shoulder to travel forward with it.

Brace the abs so your torso stays square to the machine, then pull the elbow back towards your hip. Pause for a beat with the shoulder blade drawn back.

Return under control over two to three seconds until the arm is straight again.

The mistakes that cost you the most

Twisting away from the machine is the fault to watch for, and it spoils every unilateral row. Because only one side is loaded, rotating the torso generates force cheaply. The chest pad makes this harder than on a cable, not impossible. If your free shoulder lifts off the pad at the end of the pull, the obliques have taken over.

A seat set at the wrong height is the most common setup error and takes five seconds to fix. Handles well above chest height turn the movement into a rear delt and upper trap pull.

Holding the shoulder pinned back through the whole rep is a cue that has outlived its usefulness. Letting the shoulder blade protract at the front is where the lat and the rhomboids reach their longest position, and Pallares and colleagues found full range training beat partial range work.

Uneven loading between sides keeps an imbalance permanent. Set the weight for the weaker arm.

And letting the stack slam back throws away the eccentric, which on a machine costs nothing but attention to keep.

Sets, reps and rest by goal

Each set is really two, so plan the time before you plan the volume.

For muscle gain, three sets of ten to fifteen per arm with ninety seconds. For strength, four sets of eight to ten with two minutes. In a fat loss phase, three sets of twelve to twenty with a minute.

Always start with the weaker arm and let it set the rep count for the stronger one. Closing a side to side difference takes months of that discipline, and abandoning it for one session undoes a fair amount of the progress.

Because failure is safe here, take the last set of each arm to the point where the handle stops moving. There is nothing to drop and nowhere to get stuck.

Rest can be short. You are not fatiguing your lower back, your grip is under only moderate demand, and the opposite arm has been resting throughout.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy, and unilateral rowing accumulates back volume efficiently if you have the session time for it.

Refalo and colleagues found stopping a rep or two short of failure produces comparable growth to going all the way, so the earlier sets do not need to be maximal.

Where it fits in your split

Second or third in a pulling session.

On push, pull and legs it goes mid session on pull day. On a bro split it follows the heavy work on back day. On an upper and lower split it serves as the horizontal pull. On a full body programme it is fast, because setup is a seat and a pin.

The strongest case for it is strictness. There is no unracking, no bracing position to establish and no way to heave. For people who row badly, which is most people, a supported machine removes the problem rather than asking them to fix it.

The second case is asymmetry. If one side pulls noticeably better, running unilateral rowing for a block and always leading with the weaker side is the standard fix, and you lose nothing in strength adaptation by spending a block there.

Twice a week is comfortable, because the systemic cost is low.

Variations worth knowing

Using the same machine with both arms is the obvious sibling: more load, half the time, less range. For a primary row it is usually the better pick.

The cable single arm row is the closest relative and the difference is small. The cable gives you a free path and a slightly longer arc; the machine gives you a chest pad and no thinking.

The single arm dumbbell row reintroduces the bracing demand and the hip position, which is a cost or a benefit depending on the rest of your programme.

A neutral grip, palms facing in, suits many shoulders better at the finish and changes little else.

Pulling from a higher handle position shifts the emphasis towards the upper back and rear deltoid.

And a chest supported T-bar row is the plate loaded cousin, allowing heavier loading with smaller increments than a pin stack usually offers.

What the evidence says

Fenwick and colleagues compared rowing exercises and found substantial differences in trunk activation and lumbar spine loading between them, which is the real distinction between row variations and the reason a chest supported machine belongs in a programme that already contains heavy hinging.

Lehman and colleagues measured activation across traditional latissimus dorsi exercises and found meaningful differences between movements, supporting the use of more than one pulling pattern without implying that any single row is uniquely effective.

Speirs and colleagues compared unilateral and bilateral training and found comparable strength adaptations, which frames unilateral rowing as an equal option rather than a compromise.

Liao and colleagues' meta-analysis of unilateral versus bilateral resistance training reached broadly similar conclusions across strength and performance measures, reinforcing that the value of training one side at a time lies in exposing asymmetry rather than in producing more growth.

Pallares and colleagues found full range training outperformed partial range training, supporting the full forward reach at the start of each rep rather than a pinned shoulder blade.

Schoenfeld and colleagues on weekly volume and Refalo and colleagues on proximity to failure supply the programming, with the machine making genuine failure sets practical.

Common questions

Is this meaningfully different from a cable single arm row?

Not very. Both are one armed horizontal pulls with constant tension and a long range. The machine supports your chest and removes the bracing demand; the cable lets your arm follow whatever path it likes and asks you to hold position. If your gym has both, alternate them across training blocks and stop worrying about it.

Should I do one arm at a time or both together?

Both together if time is short and you have no imbalance, since it lets you use more load in half the session time. One arm at a time if you want the longer range or if one side is behind. Neither produces more growth per hard set.

How far forward should I let my shoulder travel?

As far as it goes without your torso rotating. The shoulder blade should slide forward around the ribcage at the front of the rep. That protracted position is where the target muscles are longest, and holding the blade pinned throws it away.

Can I train to failure here?

Yes, and it is one of the few rows where you can do so with no consequences. The handle simply stops moving. Use that on the last set of each arm and keep the earlier sets a rep or two in reserve.

Does the distance setting on the machine matter?

Only in that the chest pad should let your arm extend fully without the frame blocking it. Set it once, note the position, and use the same setting every time so your loads are comparable week to week.