I have a fair bit of fitness tech knocking around in my house, but the two devices I use the most are both made by Polar – a CS500 which is married to my Litespeed road bike, and an FT80, which I use when out for a run or in the gym. However, the Polar RCX5 that I’m reviewing today could replace both those devices without me losing any functionality.

Okay, I’ll admit that I don’t use the Polar CS500 because it’s the most feature packed cycle computer on the market – if it was all about features, I’d be using my Garmin Edge 800 instead. I love the CS500 because it’s incredibly easy to read and navigate while riding, but even so, the RCX5 is a tempting potential replacement.

To all intents and purposes, the RCX5 replaces the RS800CX (though it’s still sitting  high up in Polar’s range), but while the RS800CX looked like a prop from a 1950s sci-fi movie, the RCX5 is a pretty slim and unobtrusive timepiece.

Although design isn’t the most important thing about a hear rate monitor, the less bulky and, well, ugly a device is, the more likely you are to wear it regularly. And, as testament to the good work done by Polar’s design team, I found myself wearing the RCX5 far more often than I expected to during my time with the review sample.

What’s in the box?

As is usually the case with high-end Polar products, what you get in the box depends entirely on what version you ordered. The idea is to offer a variety of bundles that suit various people with varying disciplines.

The basic RCX5 bundle consists of the wrist unit itself, a WearLink Hybrid heart rate transmitter with a chest strap and a Polar DataLink transfer unit.

The RCX5 RUN bundle has the same bits seen in the basic set, with the addition of an s3+ stride sensor, which will allow you to track your speed and distance while running.

The RCX BIKE bundle augments the basic bundle with a Polar CS speed sensor and a universal bike mount. It’s a bit of a shame that Polar doesn’t bundle a cadence sensor too, since most keen cyclists would want both.

The RCX5 GPS bundle is the most expensive and the most versatile, and is also the version I’m reviewing here. Here the basic bundle is complemented with a G5 GPS sensor, complete with an arm strap to mount it in.

Getting started

The problem with many fitness watches is that they’re big, bulky and often uncomfortable to wear all day – none of those complaints could be levelled at the RCX5. The strap makes this watch particularly comfortable – it’s very flexible and has holes running the entire length, ensuring that you can get a good fit. Even the loops to keep excess strap length in place have lugs so they stay put.

The watch itself is quite large, but also slim. It’s undoubtedly a sports watch, and even if you go for a black version instead of the red seen here, it’s not the kind of thing you’d want to wear to a formal engagement. That said, as a watch to be worn all day, so you’re ready for the gym or a quick run at lunchtime, it serves very well.

As with most Polar wrist watches, there’s a prominent, red start/stop/lap button directly below the screen. This is particularly useful when you want to lap yourself while running or cycling – there’s no need to look at the watch, and you won’t find yourself fiddling around the edges of the case looking for the right button.

There are four buttons around the edge – on the right side are the Up and Down buttons for navigating through the menus, while on the left is a back button and a backlight button.

The display is very easy to read, with a high-resolution, monochrome LCD display spanning four lines. The RCX5 has a far better screen than both the RS800CX and the FT80, and you only need the briefest of glances to check your progress.


The heart rate transmitter is also an improvement over other Polar units I’ve used. Polar devices used to ship with either WearLink+ or WearLink+ W.I.N.D. transmitters, and while the latter technology is more advanced and less susceptible to interference, it won’t work with all those cardio machines in your gym like the old WearLink+ transmitters do.

The WearLink Hybrid heart rate transmitter that ships with the RCX5 gives you the best of both worlds. You can be sure that you’re not suffering any signal interference when running or cycling in a pack, but you’ll also be able to see your real-time heart rate on your favourite gym machines.

The G5 GPS sensor is a huge improvement over the older G1 and G3 units. For a start it’s far smaller and lighter, while also having a rechargeable battery built into it. The rechargeable batter does have a downside though. If you’re ready to head out the door and realise that you’ve forgotten to charge the G5 you’re out of luck – you either go without it, or postpone your activity until it’s fully charged. When the older sensors ran out of power you simply slotted a new AA battery in.

Of course Polar would never have been able to make the G5 so small if it wasn’t for the built-in rechargeable battery, and its size is a real bonus. Although the arm strap is pretty comfortable once you get it sized right, I found that the G5 worked perfectly well in my shorts pocket when running, or one of the back pockets on a cycling top.

The G5 has a single button in its centre, which powers the unit on and off. On the bottom edge is a spring loaded flap that hides a micro-USB port, which is used for charging. Polar quotes 20 hours of use from a full charge, which seems reasonable. However, it does mean that you can’t carry spare batteries with you on a weekend hike, or multi-stage bike ride – something that’s possible with the older GPS sensors.

In use

The RCX5 is a very versatile device, able to turn its hand to pretty much any active pursuit you may have. Getting starting is simple, since there are specific selections for Running, Cycling and Swimming. There’s also an Other setting, in case you’re using the RCX5 for something different – a cross trainer in the gym perhaps, or rowing.

The splash screen for each of the discipline selectors will highlight what relevant sensors have been linked to the RCX5. In my case, selecting Running showed that the heart rate transmitter and G5 GPS sensor were both available. By contrast, if I selected cycling, it showed the heart rate transmitter, the G5 GPS sensor, and the CS Speed sensor on my bike – it should have shown the CS Cadence sensor too, but it looks like mine’s dead and I’ll have to replace it.

If you’re the sort of person that likes to keep a close eye on your performance while you’re training, the RCX5 will definitely be an attractive option. You can configure up to six info screens, each with up to four data fields. Obviously, the key is to have the information that’s most important to you displayed before you set off.

The G5 GPS locks onto satellites very quickly, so you won’t be standing around too long before you get going. The G5 also managed to hold onto its signal well, even when cycling or running through GPS hostile terrain – running through trees, or cycling through built-up areas didn’t seem to bother the G5. Of course, if you are worried about losing the GPS signal, you can use the s3+ stride sensor, or the CS speed sensor when running or cycling respectively.

As well as measuring speed and distance, the G5 will also track your route and overlay it onto Google Maps. You can then view all your routes via the Polar Personal Trainer website, along with all the other recorded data such as heart rate, speed, distance, pace, elevation, lap times etc.

The web portals for fitness equipment are becoming more and more important, and can often be a deciding factor for consumers. As well as being a place to paw over your latest results, the Polar Personal Trainer site will also let you look back over your sessions, or plan future ones in your calendar. The calendar will also give you a quick indication of whether you’re ready to go tomorrow, or whether you should take a rest day.

You can also interact with the rest of the Polar community, whether it’s posting questions in the forum, answering a question posted by another user, accepting or even creating a new challenge. Knowing that there are thousands of people out there who are trying their hardest to improve their fitness is a real incentive, and often a source of inspiration.

Oh, and getting your data onto the Polar Personal Trainer site is incredibly simple too. You just need to plug the DataLink unit into a spare USB port on your computer and start the Polar WebSync application. Your latest training data will be grabbed wirelessly from the RCX5 and synchronised with your Polar Personal Trainer account.


The Polar RCX5 is a brilliant training computer aimed at anyone who’s serious about their fitness routine. It’s versatility means that you can use it for a plethora of disciplines, and the fact that it’s compatible with the majority of Polar’s sensors, means that it can seamlessly switch between your pursuits.

As a running companion it’s a great tool, and the G5 GPS proved to be very accurate during my time with it. I would have liked to have had a vibrate alert in the repertoire – audible warnings are almost always missed when running, especially if you’re listening to music, like most of us tend to do – but very few fitness watches offer this.

As a cycling computer the RCX5 ticks pretty much all the boxes. Whether you choose to stump up for the G5 or simply sync the RCX5 with your existing CS speed and cadence sensors, you’ll get all the data you need.

The RCX5 isn’t quite as convenient to use on a bike as Polar’s CS500 cycling computer, even with the universal bike mount. But to be fair, some compromises must be made on a multi-purpose training computer compared to one focused on a single discipline.

It’s also worth noting that the RCX5 isn’t compatible with Polar’s new Keo Power sensor, but considering it costs nearly £1,700 I doubt that will put too many buyers off the RCX5.

The MSRP for the RCX5 GPS bundle is £359, but if you dig around online, you’ll probably find it for closer to £225. That makes it pretty good value for what you’re getting, as long as you need a device that can turn its hand to so many sports.

If you’re a budding triathlete, the RCX5 GPS is exactly the kind of tool that could help you analyse and improve your performances – the WearLink+ Hybrid heart rate transmitter works surprisingly well in water too, so you’ll really be able to track yourself.

But even if you’re just a keen runner and cyclist, the RCX5 makes a great case for itself, allowing you to see just how you’re progressing in both sports, without having to buy separate hardware. Personally, I still prefer using my CS500 when I’m riding my bike, but I’m very tempted to get an RCX5 too.


  • Incredibly versatile
  • Slim and comfortable to wear
  • Small, light and slim GPS pod
  • GPS unit is very accurate
  • Can be used for any number of sports
  • WearLink+ Hybrid heart rate transmitter works with gym equipment
  • Works with speed and cadence sensors


  • Some will prefer an all-in-one GPS watch
  • Doesn’t work with Polar power meters
  • No vibrate alert
  • You need to remember to charge the G5 GPS

Score: 9/10

Manufacturer: Polar

MSRP: £359