The RCX5 is the lowest profile fitness watch of the five sport watches we have tested this year (See our Fitness Technology Round-up for full details), sitting at just 1.1cm high on the wrist. While fully integrated with GPS, the flag ship Garmin Forerunner 610 towers above the RCX5 and yet has a smaller screen.
Measuring 24.5 x 4.6 x 1.1 cm and weighing 46g, the RCX5 is also 33g lighter than the Foreunner 610 and 22g lighter than a Casio G-Shock Classic. We weren't keen on the design, though. While we can forgive the manufacturer's name being on the watch face, but manufacturers take note: unless you have made a car, don't emblazon the model number all over your product. The watch has the word "Polar" written in no fewer than six places, and the words "Performance Science" written on the face and down the side of the strap, which is frankly rediculous.
The 1.2 x 1in screen is easy to read and the buttons are well placed and big enough to be operated wearing gloves while staying out of the way during exercise. We especially liked the big red timing/record button which is on the face of the watch, ready to punch when you stop or start a workout.
The display can show up to six different screens that the user can scroll between during a workout. Each of these is customisable with everything from a live readout of calories burned (based on the user’s heart rate and weight), to average cadence if you’re working on building speed, pace, miles covered or more.
There is also a heart-tap function, which can display a data set of your choosing when you bring the watch up to the heart rate monitor. Like the best innovations, this is something we didn't realise we wanted until it was invented for us. Having the ability to check the time of day during a run simply by lifting the watch to chest height made us wonder how we managed without it.