The best training for running is running.
This is a fundamental thing to remember. Whilst the other elements have their place, if
you are going to be a good runner - you have to run, which extends to marathon runners as
if you are going to be a good marathon runner - you have to run a lot!
You will need a variety of paces to your training, as all but the most novice marathon
runners do, but as an elite athlete you need to target that pace quite specifically to the
various sessions you are to run.
See the other sections in the Advanced Marathon Section to fill out the details.
Strength work
As a marathon runner it is important to have good strength. This doesn't mean that you
need to be built like a body builder, but having light, strong muscles will enable you to
be able to perform at your best. This is because you can perform each movement with less
effort. It is important to ensure all the exercises undertaken a specific to running and
the number of repetitions aren't going to build unwanted muscle mass.
Mobility Work
There are two components to this
Making sure you have the range of movement required to run efficiently.
Keeping your muscles in good condition (which includes good mobility) helps reduce injury
risk.
Cross-Training
Primarily this is needed at times when running aren't possible or desired. If you are
injured you maybe able to work hard aerobically doing an exercise not involving the injured
muscle. In a training break or early in the training cycle doing other activities is good
for the maintenance of interest.
Technique work
You have now reached a level of performance where you should be concerned with how you
are running technically. A regular session devoted specifically to this, or work prior to
other sessions will ensure you get the best from your training.