So how DO race time predictors compare?
Bet you can guess where I am going with this bit....
Line from top to bottom: Marathon prediction, Half marathon, 10k and 5k What they showAll 6 methods give very similar results. There is a greater variation from a short race to marathon prediction between the results, but this is similar to real life - I don't think you should use a 5km result to predict a race 8 times longer - there are so many other variables to consider. The McMillan and Purdy points methods give similar results to the others based on the few test times I have tried (1 fast, 1 medium and 1 slow time for each of the 4 distance). Time predictors give a very similar result to each otherSo how do these compare to REAL runnersSo you know how the theoretical predictions compare, but what about real runners The Power of 10 website publishes runners and their race results (a handy website to keep a track on those PB's!). For my purposes this is a useful set of actual race times. Going through the website I noted down runners times where they had run 3 out of the 4 of my race distances. This was quite a lot of work - more than I had anticipated when I started looking at this bit. This gave me quite a list of runners race times over several distances (my first list was 500 runners... I have added more as I get time to). Now I can compare real runners to the predicted race times! When I looked at this I only looked at the runners absolute PB for the distance - whether they were on the same day or 5 years apart. My thought for comparing PB's is that this is as fast as the runner can go, comparing races within a certain time of each other allows for variations due to weather, courses, feeling off, a hard run the week before, running with friends, hills, rain, sun, and all the other excuses I have used in the past This gave these charts.
The 4 charts show actual race times for each distance and the corresponding runners race times for the other distances, the solid lines are the predicted times based on the charts distance finishing times As before the top line is the marathon, then the half marathon, the 10km race and then the 5km race. The solid line is the predicted race time from the 5km race result or marathon race result and the dots are the actual times of the runners. X-Axis is the race distance race time. The predictions follow that actual times runners get however there is a variation from predicted to actual. This is to be expected - different courses, weather conditions and so on can do this Conclusions |