The last 9 months I've learned a lot about how to run high mileage--its benefits and its drawbacks. You could describe the last three years of my training life as one of trying to figure out how to run 100 plus miles per week.
It seems easy, right--you just go out the door and average 14 miles a day.
But the problem of course is that training only works if you are well-trained enough to absorb it. Although I've been running on and off for 20 (gulp!) years, these last 3 years were really my first attempt to push the envelope of the volume of miles that I've run. Even in college, I would never run much more than 65 miles per week for an extended period.
So, over the last three years, more often than not, I've run too much too quickly, and in the wrong ways. This is the primary reason that it took me so long to improve on my first real marathon attempt. I would have moments where the miles would really work well for me, and I would do things in training that I never could have done on lower mileage. But I couldn't time those moments--and I had just as many moments when my legs were totally dead, and my races unreflective of the work I'd put in. On 65 miles a week, I could race consistently. Upwards of 80 miles per week, I was on and off--occasionally popping an extra-fast performance, but more often finding myself dead-legged--no pop--in the middle of a race.
Two things made the difference this time:
1) I didn't run too much for too long. About 6 weeks out from my marathon, I began to bump my miles, but I peaked my mileage at three weeks prior to the race--at the point that my body was still absorbing the extra work, not rebelling from it.
2) I was in familiar territory. I didn't go higher than I'd ever been, and I started my build from a comfortable place. The last three years of work--though they hadn't produced a good marathon performance--had made my body familiar with 80+mpw.
Those are the things that helped me run a PR.
However, I do think that I made some mistakes that kept me from totally capitalizing on my fitness. (At least I hope I did, because I think I can run faster.)
1) I put too much emphasis on weekly mileage in final phase of training. In order to run 5:45 pace instead of 6:00 pace, I'm going to need to do more quality work. This doesn't mean that I shouldn't run upwards of 100mpw before my next marathon, but only that I shouldn't be so worried about losing fitness by dropping the miles down to 60 or 70 at times in the 6 weeks prior to the race so that I can get the freshness back in my legs that is necessary to do the long MP tempos I'll need to make the jump.
2) Along the same lines, as a guy who has been running for a long time, it's going to take big workouts to make changes in my fitness. One "big workout" is a 110 mile week, for sure. But as I get closer to a marathon, I shouldn't worry about taking a couple of low mileage days (or heaven forbid, days off) in order to rest up to run a 15 mile MP workout, or a set of mile repeats at 10k pace, or a steady 24 miler--and a couple of days afterwards to soak up the benefits.
3) Finally, I could do more pure speed work. Speed has always been my strength as a runner, but in marathon training I have a tendency to get away from that strength. Some short workouts like 6 x 400 @ 3k-5k pace or 8 x 200 a little faster will make MP that much easier and help me maintain power in my stride.
One thing I finally learned, however, is how to run consecutive 100+ mile weeks and really benefit from it. The key (duh) is to stay conservative with the pace and also with the workouts. Oh yeah, and also get more than 7 hours of sleep. The temptation, when we're really motivated to train, is always to ramp everything up. This is a recipe for burn-out for me. I've found a lot of good training partners who keep me easy on easy days, and that's the key there.
So, there's the dull training post. No philosophical speculation. Just some down-home pragmatic reflection.