Predicting race times for Race Walkers by Julian Hopkins (Former National Event Coach)
How does your personal best time for 10 km compare with your best time for 20 km? This might seem a trivial question but I think it is very useful to be able to relate performances at one distance to performances at another for several reasons. Firstly, a simple comparison of your times at different distances with the predicted times will indicate over which distance you are relatively weak. Secondly, if short distance times allow long distance times to be fairly accurately predicted, you can set yourself realistic targets for the longer distances. I don't think that I need to emphasise the advantages to be gained from walking at a level pace - they have been spelled out by physiologists and coaches often enough as well as being demonstrated by the world's best in recent years. As a result of looking at this problem, I have produced the following rules of thumb for predicting times at longer distances.
1) To predict a 10 km time from your 5 km best, double your time for 5 km, and add one minute. For example, if you are a 23:00 performer, you should be capable of 47:00 for 10 km. Consequently you should aim to reach 5 km in about 23:30. If you cannot achieve 47:00 then you need to improve your specific endurance. The correlation between a 5km and a 10 km performance can also be used in reverse e.g. if you have a personal best of 23:15 for 5 km and manage to record 47:00 for twice the distance, this would indicate a need to improve your basic speed giving you greater potential at longer distances.
2) To predict a 20 km time from your 10 km best performance, double your time for 10 km. and add three minutes. So if you have achieved a 47:00 10 km. you will now be aiming for 97:00 at 20 km with a half-way time close to 48:30.
3) To predict a 50 km time from a 30 km performance, first find three quarters of your best 30 km time. Then add the result to your original 30 km. time to give you your predicted 50 km time. For example, if you have walked 30 km in 2h 30m (about 2h 41m for 20 miles) you should be capable of about 4h 22m - 4h 23m with the correct preparation. Your even pace schedule will require about 2h 37m - 2h 38m at the 30 km point.
I should emphasise that these rules are only rough guides to possible performances. Although you can no doubt think of exceptions to the rules amongst even the best walkers, it should be remembered that even they do not always achieve their potential at various distances due to incorrect training or not having ideal conditions when in their best form. Generally speaking, the rules seem to hold up very well.
NB. If you do not have a personal best at 5 km you can estimate what your best performance would be by adding 5 seconds per kilometre to your best pace over 3 km.
N.B. Several 20 mile equivalent times are shown in brackets as a guide.