mark - I really think you should err on the side of shorter distances, and mix in a little bit of MP on some of the shorter runs. To give you some perspective, a club mate of mine is aiming for sub-2:40 and is known for being a bit overly keen on getting training in, so needs to put a lid on things now that all the hard work has been done. Coming down from 90 mpw, coach advised him to bin his plans to do 16 miles on Sunday just gone (i.e. two weeks out) and just do 12 instead.
(As an example of MP stuff during the taper, this evening he's got him doing a 45 minute run, comprising 15 mins @MP+15secs/mile / 15 mins @MP / 15 mins @MP+15 secs/mile. I only know this cos I said I'd do it with him for a bit of support. I'm not running the marathon.
)
If I was doing the marathon I'd probably do no more than 10 miles LR one week out, then probably just another 3 runs in the final week, nothing more than 6 miles, with just the odd mile @ target MP to remind the legs what pace they need to be running on the day.
You can't lose any fitness at this stage, but you can (a) freshen up, (b) run a little MP on fresh legs which feels easy and will give you confidence, and (c) conserve energy, which along with a sensible carb-load will maximise your glycogen stores.
Edited: 11/04/2012 at 09:56