I have been using Jack Daniels racing/pacing calculator runsmartproject.com/calcula... for some time now - firstly to know what pace to run at during training runs and secondly to estimate a time to aim at when running a 10K that I was training for ( and completed very recently)
However- my previous PB at Parkrun was 32: 30 and the calculator was telling me that the equivalent race time for a 10K was around 1hour 10 minutes - so I used the training paces to run a 1 hour 10 minute 10K and found them to be challenging but doable. BUT - when I did the 10K , I ran it in a time which was quicker than twice my 5K PB??? Have been wondering how that happened and even suspecting the time that I was given at the end of the race.
Now, after getting a new 5K PB yesterday of 30:34 . I put that into the calculator and get a projected 10K time of 1:03:36 , which is almost exact within 10 seconds!!!! Is all this merely coincidence, magic or Science???