But does it matter to your fitness levels? I did my first parkrun today. I was around ten minutes faster than on previous 5k runs at 34:51. It is a dead flat, sheltered, measured route. I can't be quite confident of my little pedometer (now discarded for a forerunner 220!) and just like when I'm driving I tend to drift off and run slower and slower! Does the speed you complete each run in, actually matter for your cardiovascular, all over fitness though? I don't finish breathless, despite my young nephew joining me and suggesting I sprint the last bit! I should probably be pushing myself a bit rather than gently coasting but what do you all think?