It's a natural outcome of keeping a running diary. You become very concerned with how many miles you ran this week, but not with how fast you ran them. In the next few years we may see a shift back to quality rather than quantity. Hunt usually runs between 85 and 105, slightly higher immediately before marathons. But he patterns his workouts.
Rest is an important part of a training program.
There are times of the year when you just go to the beach. Maybe not, because one of the great talents of today's top runners is not merely to race hard, but to be able to train hard so as to be able to race hard. Nevertheless, the runner who can increase training mileage should expect to improve as long as quality is not sacrificed for quantity. If you push your weekly mileage from 30 to 60 miles a week, you still may not be able to qualify for Boston, but you probably may grab that P.R. the next time you try a marathon. Eventually all of us must face the fact that nothing comes free.