Losing my running commute this past spring has had a massive negative effect on my weekly mileage. It's such a bummer. Not enough that I'd go back to my old schedule and have to suffer through the reason my schedule changed, but a bummer nonetheless.
I usually have the most success with a marathon when a vast majority of my training is at a weekly mileage of about 45 or higher, including a bunch of weeks over 50. Historically, when I've had at least three weeks in a row at 55 or higher, something has started hurting, so that seems to be about my breaking point, and I'm usually rock solid going back and forth between 45 or 50 and something around 55. But I can't tell if that pattern holds true because my mileage never got there this year.
This is how it broke out (I'm cheating a little on my counting. I usually do my long runs on Sunday, but on weeks I had to do a Saturday long run instead, I'm counting as if I did it on Sunday instead, so there aren't any artificially high mileage weeks that had two long runs):
Low 20s: 2 weeks (it rained and I totally skipped my long run the week before Memorial Day, plus this week of tapering)
Mid 30s (I'm saying about 33 to about 37.5): 3 weeks
About 40 miles: 4 weeks
Mid 40s (again, about 43 to 47.5): 4 weeks
50 miles: 1 week
Yow. Usually writing out my training miles is a confidence booster for me, but not so much this year! 14 weeks of training, counting taper. All my weeks in the mid-40s and higher were in July and August. And no weeks over low 50s.
Not a recipe for success!
If I were still running to work, I'd be adding at least 7 miles to each week, usually more like 14 and occasionally 18. That would have pumped those numbers up perfectly.