Originally Posted by
Mr S1
I believe the principle is the same for running as cycling, and when I first started doing the London to Brighton I was told if you can comfortably do 30 miles you can do 60. Applying the same logic if you can do 13 miles without any problem you should be able to do 26 without too much difficulty.
There's a huge difference between running 13 miles and running 26 miles IMO
If your already running 12 miles then your a long way down the road but there's lots to consider when running a marathon. The main one being nutrition, if you don't eat right and prepare then your body will run out of fuel at about 20 miles and you will hit the so called wall. So carb loading is vital in the week leading up to the race and you will need to take carbo gels or bars with you on the road and make sure you are extremely well hydrated.
As already mantioned have a read on runners world as there are plenty of training guides and tips but most of them, even the four hours plus schedules, require 5 or 6 runs per week.. When I did London in 2006 I trained mostly 3 but towards the end of training 4 times a week as I was trying to get the miles in.
It's one of those things where the more you put in the 'easier' it will be. From a good half marathon level I would say you need at least 3 months to properly prepare for a marathon. It's a huge commitment on your time when you have to go out for 2 hour plus runs.
HTH
Martyn