I read a lot of people talking about reverse splits in Marathons as the best strategy but less detail on how extreme to make the difference between the two halves. Let me give a (not so hypothetical) example.
I am running the Brighton Marathon in April 2013. A time under 3 hours 15 mins gets me a good for age place in the 2014 London Marathon. I have a 1:29 half marathon under my belt in the summer so 3 hours 4 minutes might be a reasonable target, which is scarily close to 3 hours.
I would like to give myself a shot at under 3 hours but do not want to go off so quick and blow up in the second half - perhaps even ruining my good for age time for London. So a reverse split would seem to be the way to go. If I go for 1:32 in the first half does that give me too much to do in the second half? Should I go even slower in the first half.?
I have a couple of 20 mile races to rehearse at but interested if there is any formula or advice on a reverse split.
I am in training for the Brighton Marathon and have the Bramley 20 mile race in February and the Finchley 20 in March (4 weeks before the race). I would be grateful for any advice on how to use these. I ran the Windsor half marathon at 6:46 pace or 1hour:29mins which would suggest I could do something like 7:02 marathon pace or 3hours 4 minutes. I was thinking of using the first to see if I can sustain this pace for 20 miles and the second to see if I can go one further and run 3 hour pace. Is there a risk of burning out though if I run both these at Marathon pace?
Should I be treating them as just long slow runs or do I push myself?