One of the beautiful things about reading lots of blogs is that you have lots of measuring sticks to compare yourself by. One of the most significant (for runners) is weekly mileage.
Compared to many of the marathon training runners I read, my weekly mileage is on the low side. During the two months this year so far, I have varied from low/mid-30s to mid-40s. More the 30s in January, and 40s in February (though this last week was about 35-36 miles--I'm calling it a cut-back week).
It's hard to say whether I'll get higher than mid to upper 40s in March, either. My marathon peak number has always been just a little over 50 mpw, and I don't see going higher than that this time around. Unless I can bump up a couple midweek runs from 6-7 miles (currently) to 8-9 miles, I may not hit 50 at all. (The reason these runs have been a little shorter than I would like is not because of lack of ability to run, but rather due to lack of time in the mornings before work.)
Some of the bloggers I read are also training for Boston, and thus are on the same time line as me. Compared to some of them (but not the ones who are truly insane) I am definitely on the low side. My first example is in the 50s right now, and probably heading for the 60s in March. (The second one runs marathons on the treadmill, so there is no comparison! I write this with true admiration and amazement, mind you!)
The reason my mileage is low (and will remain that way, relatively speaking), is that I generally only run four days a week. A fifth running day is an exception, and might occur if I have a short race during the week, or I'm on vacation, and running is my only exercise option.
I'm fairly comfortable with low totals because I believe I pretty much meet my training objectives with each run I do. My first run of the week (Monday or Tuesday) is an easy run, 6-8 miles. On Wednesdays I do speed work, either 800s or other short repeats, or a tempo run, again with a total distance of 6-8 miles. Friday I do a medium long run of 8+ miles, with some of the miles at goal marathon pace.* Then my long run is over the weekend, on Saturday or Sunday, anywhere from 12 to 22 miles, depending on where I am in the training cycle.** Those runs could add up to anywhere from low-30s to mid-40s.
The question is, can a person adequately prepare for a quality marathon performance on less than 50 miles a week of running? Obviously, elite runners and top non-elites run a lot more, probably 80-100 miles a week (which is completely out of reach for most of us!). Other "good" runners might target 50-60. I think it's not unusual to see mid-level runners (like me) in the 40s, and doing just fine.
In the last year or so there was an article (which I have no idea how to find) that said most of us are running way too few miles for our training objectives. The bottom line was that what we might consider marathon training volume is more appropriate to the half marathon distance, and perhaps it's better to run shorter races (half mary, 10K, 5K) than run a marathon on this amount of training.
I thought the author had a good point in that there is no shame in transfering your training efforts to shorter races, if that is your preference. However, I do dispute whether you can run marathons on moderate-mileage training. I believe you can. I also believe it's important to get in a couple of 20+ mile runs; I would be very uncomfortable running 26.2 miles if I hadn't done 20 at least once (preferably more).***
I have no real conclusion to this post. I believe that everyone has a weekly mileage range that works for them. Some can pump out high volume and not get hurt (or over-trained), others manage to run their marathons on what seems like shockingly low mileage (to me), and then those like me are in the happy middle.
This morning: 7.10 miles easy, 10:15 average pace.
*Last Friday I did 11.11 miles, with two warm-up, three at sub-9:30 (actually 9:20s), three around 9:00 (9:02, 9:04, and oops, 9:18), and three as close to 8:30 as I could get (8:45, 8:25, 8:35).
**Yesterday's long run was only ten miles, due to snow on the ground, time limitations, and my decision to make it a cut back week between 20-milers.
***So far I've done 17.5, 19.25, and 20.65. I have three more 20-ish milers on the schedule (one is actually a 30K), and I figure if I somehow miss one I'll still be in good shape.