At the end of the booklet you'll find handy reference charts showing all the schedules. People differ greatly in ability, but we recommend that before starting a marathon program, you should have been running about a year. You should be able to comfortably run distances between 3 and 6 miles. The key to the program is the long runs on weekends, which build from 6 miles in Week 18 to 20 miles in climactic Week 4. You can skip an occasional workout, or juggle the schedule depending on other commitments, but do not cheat on the long runs.
Rest is an important component of any training program.
As the weekend mileage builds, the weekday mileage also builds. Add up the numbers, and you'll see that you run roughly the same mileage during the week as you do during long runs on the weekends. Midweek workouts on Wednesdays build from 3 to 10 miles. Please note that we do not recommend doing your long runs at marathon pace. That adds too much stress, particularly when coupled with the speed sessions scheduled for Tuesdays and Thursdays.