Having dominated the heart rate monitor market for a while, Polar products come with an excellent pedigree behind them.
Setting training zones from the inbuilt self test or by the manual input of three zones is easy and intuitive ,and the instructions are clear. A handlebar mount costs an extra £6.
The WearLink strap feels a bit on the chunky side and the elastic also has fairly sharp edges; we’d be tempted to replace with one of the old plastic T31 straps.
Syncing is quick and the actual monitoring very consistent. However, the display is on the small side and the buttons ﬁddly but this criticism can be levelled at most of the wrist monitors. Training data recall is limited but all of the essential information (such as time in zones) is readily accessible.
Where the RS300X really falls down is the arm-band GPS pod which, as well as being clunky, took an age to acquire a signal and struggled in built-up or wooded areas. With sleek, fully integrated products now available, it seems a bit dated.