bainsy - Very nice reps. Looks like you're at a nice stage of significant returns to something like the sort of paces you're used to. Cycling volume's clearly been useful for keeping the engine ticking over.
RS - Good luck in knocking a tasty chunk out of your PB on Sunday!
I've been filling my face with nice tasting fatty, sugary foods, and avoiding running. A very pleasant 34 miles on the bike today though, and now looking forward to flying out to Tenerife tomorrow for the marathon-recovery holiday. Just about to pack and will be giving Imelda Marcos a run for her money: running shoes, cycling shoes (road), cycling shoes (MTB, doubling-up as hiking shoes) and flip-flops. I think the idea is to manage a little more R&R vs. activity than in Mallorca last year, but it would be rude not to cycle up the volcano while we're there.
If you have the spare time over the weekend, I think it's worth having a big old endurance fest of a long ride and a long run, preferably in that order since the recovery from riding is easier than from running. A typical training pattern for me in marathon build-up would be alternating weekends of run/run and bike/run, for Saturday/Sunday. Something like 50 - 60 miles on the bike on Saturday and 20 mile run on the Sunday. Maybe some rides during the week in the place of easy runs. (I do 2/3 spin classes in the week even in heaviest marathon training.)
Or maybe replace the long run no more than every week in three, but there really is no substitute for time-on-feet and running long miles on tired legs.
Funny old game. If you like boxing how can you not like jogging? Boxing is basically jogging on the spot whilst being punched. So jogging is like boxing, except you avoid getting punched, and you can admire the scenery.
HR's a funny thing and I'm sort of glad I gave up trying to understand it, and have for a few years worked off perceived effort and estimating training/racing paces by cross-referencing different race distances and sessions against each other. During training for my first marathon I was steadily getting target pace corresponding consistently with HR of mid 150s - 160, but then on race day it surged to 167 within a mile and never came down. I then averaged 168 - 170 for my first three marathons, compared to a max of around 200. But I'm sure there are variations between what different runners can maintain, so it's always going to be educated guess work based on your own experience.
Re: eeking out PBs as age catches up with you... I've run numerous non-PB races at shorter distances, either because they're low-key, slower course, etc. but that's all part of the week-to-week fun of competitive running. As long as you can have a stand-out race every now and then to look back, it's all good. The marathon is quite different though; 3/4 months of dedicated training with a race at the end which, if you cock it up, you can't just go out and run another one a couple of weeks later. So I can totally understand Simon basically nailing one and being happy to walk away from it, especially as he's still quicker than me over sensible distances. Equally I'm not rushing into another one till I know I can definitely run quicker. 2:32 or whatever at London really wouldn't be worth the ball-ache of all that training!