The long and short of it

A standard running program for a marathon or similar distances that's been advocated in many websites like Hal Higdon's,
Cool Running, etc follow one principle: Run hard one day and either rest or run easy the other day.A typical week's run could include one tempo run(pace at just below the lactate threshold), one or two steady paced runs and a long run, run slowly; and the days in between these runs are taken as recovery days.
But the problem with this kind of a training program is that, there is a tendency to run the hard days really hard and get wiped out so that you have to literally drag your a$$ the next day for the easy recovery run. Also the one day's recovery may not be sufficient when hard runs are run with a high intensity, which is the cause of injuries among most runners. While injuries like shin pain or ankle pain go away easily with a day or two's rest, other injuries like runner's knee and achilles heel are long-term injuries that take a lot of time to recover. I have had this problem the last semester, when in training with a friend, the over-enthusiasm of my friend made me run hard every day without taking a break for almost a week and this finally lead to my not being able to set foot in the stadium or the road for almost 2 months.
There is a guy whom I see regulary in the stadium, who runs just 12 laps a day around 5-6 days a week. He does these runs at an even comfortable pace without any sprinting towards the end of the run . These are basically the steady paced runs, but he did it every day. As simple as his running plan may seem, he made major improvements to his speed during the course of two semesters with no hard or intense runs at all.
This is the training philosophy(Long short runs and short long runs) which is also advocated by a great coach Farrell, and which I have currently adopted in which I run 10-12 kms every alternate day at a steady 8min/mile or 5min/km pace through out the run. Over the course of next three months, I expect to increase the number of runs from three to five all the while running the same distance. According to the collapse point theory, as a thumb rule, you could run upto 3 times the average daily run distance, which would mean to run a marathon, I should be averaging 14kms a day or 98kms/week. While this might seem a little too far-fetched right now, in 3-4 months I should be hitting 80-90kms/week, which would be more or less ideal mileage for my first marathon.