Half marathon challenge

by John C
(London)

Adjusting the half marathon time, when conditions were challenging :

"Hi Marius,

I have just done a half marathon with 4 weeks to go until my marathon. The build up to date has been fantastic with big PB's over 5Km and 10KM (15.13 and 32.14)but todays half has taken place in gale force winds to the extent that an UK international targeting a 66 minute run ended up winning in a time of 70.30. I finished second in 72:00 feeling very strong but ultimately my time has been hugely effected by the conditions.

What should I do when the marathon race day plan would appear to be quite dependent upon today's half marathon time?

Many thanks

John"

Answer: Hi John, and congratulations on your personal 5k/10k records !

You definitely want to adjust the half marathon time- and use that adjusted time to predict your marathon finishing time.

Do the following :

1) Use your 10k time and find the predicted your marathon time based on that.

2) Look at the scoring board and compare other runners times, ideally the last few months to see if you can find a pattern there. If it is say 4 minutes, adjust your time as well.

Compare the two above and find the middle ground to be sure.

That should make you all set, winds can have a huge impact especially in road races so it does sound that way in your case.

No worries thought, the above will be more than good enough to give you a nice enough idea - to be right on target for the marathon day.

all the best,
Marius