By Jack Atkins, Home Gym Equipment Specialist · Updated 16 September 2026
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Sunny Health & Fitness
Sunny Health & Fitness has sold an enormous number of these, and once you see the price the reason is obvious. At £130.99 the SF-RW5639SMART costs less than a decent pair of running shoes, and it is comfortably the biggest seller in the rowing category we track on Amazon UK, with roughly 26,000 ratings behind it. That kind of volume tells you something real about who buys home cardio kit and what they will actually spend.
It also sets up the central confusion about this machine. It is called a rowing machine, it looks broadly like one, and it will give you a sweaty full-body session in a small room. But the mechanism underneath has almost nothing in common with the cable-and-flywheel rowers that dominate gyms, and if you buy it expecting to train for a 2,000 metre piece you will be disappointed within a fortnight.
Check the Sunny full motion rower price on Amazonaround £131How we review
This review draws on Sunny Health & Fitness published specifications for the SF-RW5639SMART, the live Amazon UK listing checked on 16 September 2026, and the repeated themes that show up across thousands of verified owner reviews. We have not put months of metres on this particular unit, so we report consistent patterns and the known behaviour of hydraulic resistance rather than inventing a hands-on impression.
Picture a spare bedroom, a budget that stops somewhere near £150, and someone who wants to move their whole body without pounding their knees. That person is exactly who this machine suits, and they will get genuine value from it. The same goes for anyone returning to exercise after a layoff, older users who want gentle resistance they can dial down, and households where the machine has to be shifted out of the way between sessions.
It suits nobody who wants to learn to row properly. If your goal is technique that transfers to a club erg or an actual boat, start with our rowing machine technique guide and then buy a machine with a single handle and a cable, because this one will teach you a different movement pattern entirely. Our breakdown of what type of rowing machine is best covers the four resistance systems and where each one earns its place.
| Resistance type | Hydraulic piston cylinders, one per arm |
|---|---|
| Resistance levels | 12, adjusted by dial on each cylinder |
| Arm motion | 360 degree full-motion pivoting, two independent handlebars |
| Monitor | LCD showing time, count, stroke rate, calories, total strokes |
| Connectivity | Bluetooth to the free SunnyFit app |
| Seat | Padded, elevated, wider than the previous model |
| Pedals | Non-slip with adjustable straps |
| Footprint | 141.5 x 57.4 x 73.9 cm (55.7 x 22.6 x 29.1 in) |
| Product weight | Approx 16.5 kg |
| Max user weight | 180 kg |
| Model | SF-RW5639SMART, black |
Sunny lists this machine in its hydraulic resistance rower range, and the full specification sits on the official SF-RW5639SMART product page.
A hydraulic cylinder is a sealed tube of fluid with a piston through it, and the dial on the outside changes how easily that fluid moves. Turn it up and the piston meets more opposition. That is the entire mechanism, and it explains both the low price and the two limitations that matter most.
The first is heat. Push fluid through a restricted port for twenty minutes and it warms, and warm fluid moves more freely than cold fluid, so the resistance you set at minute three is not quite the resistance you are getting at minute twenty-five. This is not a defect in this particular unit and it is not something Sunny has skimped on; every hydraulic rower ever built behaves this way, and the effect is most obvious on long steady sessions rather than short intervals. Owners who row for 15 minutes at a time rarely notice it at all.
The second is the shape of the resistance curve, or rather the absence of one. On an air rower the fan meets more air the faster you spin it, and on a water rower the paddle meets more drag the harder you pull, which is why both machines punish a lazy stroke and reward an aggressive one. A hydraulic piston mostly does not care. Level 8 feels like level 8 whether you are gliding or heaving, so you cannot make a session harder by rowing harder; you have to stop and turn a dial. For steady-state cardio that is fine. For intervals it is a real handicap.
Instead of a single handle on a cable, you get two independent arms that pivot through 360 degrees. Sunny markets this as full motion, and the closest real-world comparison is sculling, where each hand drives its own oar through an arc rather than both hands sharing one bar.
In practice it opens up movement patterns a fixed handle cannot reach. You can pull wide and hit more rear delt and mid-back, pull narrow and close to the ribs for more lat, or angle the arc to suit a dodgy shoulder. Several owners use it as an upper-body machine on days when their legs are wrecked, which a cable rower does not really allow.
What it does not do is teach you to row. On a proper erg the power sequence runs legs, then body swing, then arms, in that order, and the whole point of the single handle is that it forces you to link those phases into one chain. Split the handle in two and the chain breaks: your arms start pulling early, your legs contribute less, and the drive becomes an upper-body movement with some leg press attached. That is a perfectly good way to raise your heart rate. It is poor preparation for a Concept2, and it is worse preparation for a boat.
The seat and pedals are better than the price suggests. The padded seat sits high and wide, which matters more than it sounds if you are getting on and off with stiff hips, and the pedals have adjustable straps that hold a shoe rather than letting your heel wander.
The LCD gives you time, stroke count, strokes per minute, calories and a total stroke tally. There is no 500 metre split, no watts and no drag factor, and that gap is the reason this machine cannot support structured training.
Split time is how rowers measure everything, because it converts effort into pace in a way that is comparable between sessions, between machines and between people. Watts does the same job in raw physics. Without either, your only honest metrics are minutes and stroke count, both of which can be inflated by rowing badly and quickly. You can still train hard and improve; you just cannot prove it with numbers, which is a genuine motivational problem for some people and no problem at all for others.
The SunnyFit app logs sessions over Bluetooth, costs nothing and asks for no subscription, which is more than several rivals at twice the price manage. It is a session diary with guided workouts attached rather than a performance tool.
Yes, provided you buy it for what it is. Indoor rowing done consistently produces measurable cardiorespiratory improvement, with a 2023 trial in post-menopausal women finding meaningful aerobic gains from a structured indoor rowing programme, and this machine will get you to the NHS target of 150 minutes of moderate activity a week without loading your knees the way running does. That is the whole case, and at £130.99 it is a strong one.
The alternative at a similar budget is a small magnetic rower, which gives you smoother, more consistent resistance and a single handle, but usually a shorter rail and less interesting arm movement; we compare the cheapest options in our best budget rowing machine UK guide and go lower still in our rowing machines under £100 roundup. Sunny's own magnetic model is worth a look too, and we cover it in our Sunny magnetic rower review.
See today's price on AmazonIt depends what you want from the word. As a low-impact machine that works legs, back and arms together for cardio, it does the job at a price no cable rower can match. As training for a Concept2 or a boat it falls short, because the two pivoting arms move independently rather than following a single handle through the legs-body-arms sequence.
Hydraulic pistons mounted on the two arms, adjustable across 12 levels by turning a dial on each cylinder. Sunny lists it under its hydraulic tension range rather than its magnetic one, so there is no flywheel, no magnet and no cable. Hydraulic cylinders warm up as you use them, which means the resistance drifts slightly over a long session.
No. The LCD monitor covers time, stroke count, strokes per minute, calories and total strokes, which is enough to know you did something but not enough to train by pace. If you want to chase splits or hold a target wattage, you need an air or water rower with a proper performance monitor.
The listed footprint is 141.5 x 57.4 x 73.9 cm, so it fits into a bedroom corner or along a wall without dominating the room. At roughly 16.5 kg it is light enough for one person to tip up and move, which is the main practical advantage over a 30 kg air rower. Leave a little clearance either side because the arms swing outward.
Yes, and there is no subscription gate on the basic tracking. The rower connects over Bluetooth and the app logs your sessions and offers guided workouts. Treat it as a bonus rather than a reason to buy, because the underlying data from a hydraulic machine is stroke counting rather than power measurement.
Anyone over about 100 kg who plans hard daily sessions, anyone learning rowing technique for a club or a race, and anyone who wants resistance that builds the harder they pull. The 180 kg user limit is generous but the hydraulic cylinders are the wear item, and they are working hardest for heavy users. Consider a magnetic or air machine instead.
An honest DMASUN rowing machine review: 32 electromagnetic resistance levels, a self-powered flywheel, a real 500m split on the monitor, and where this young brand still carries risk.
An honest Sunny Health & Fitness SF-RW5515 review: a 130cm extended rail rated to 198cm, 8-level magnetic resistance, a basic LCD and what £219 does and does not buy you in 2026.
An honest MERACH foldable wood water rowing machine review covering the solid wood frame, 180 degree fold, 180kg capacity, Bluetooth monitor and who should buy it.
An honest YOSUDA foldable wood rowing machine review covering the 22L water tank, FSC beech frame, 182kg capacity, vertical folding and the basic console.
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