The purpose for such a geeky toy is to measure my performance, highlight any peaks or troughs, and to help ensure i match my training to matchday levels.
Amongst the various data you get (including heart rate, distance covered, average speed, calories used, etc etc) is a map of your route. I wet myself laughing when I saw the “mr messy” style squiggly lines all over the pitch. But this covers a total of 5 miles! Not bad on a pitch that was so muddy it was almost treacle to run in!