This is because we think it is important to have a good base of general fitness (which is
usually enough to get you round a marathon at a slow pace) before you step up the training
and do the more specific work that is required to start bringing your times down.
If you step straight up to this level you risk injury or illness from overtraining.
Not quite an Intermediate yet?
If you are not yet at this level, then we would suggest that you try
to follow a regime of 3-4 runs a week, building up to this level slowly from your starting
point.
There is much more help in the Beginners Marathon
Running section of the site.