This plan is designed for low-mileage runners over the age of 40 who are preparing for a marathon. The plan is 20 weeks long and features five workouts per week. It begins with approximately 2 hours and 59 minutes of total training in Week 1 and peaks with 6 hours and 10 minutes of total training in Week 16. You should be able to run 6 miles before you start the plan.
What makes this plan a good fit for runners over 40? Three key factors: Nine-day weeks, block periodization, and cross-training.
Nine-day weeks: Serious runners over 40 find that they can train just as hard as ever in individual workouts, but they can't do these workouts as often. The most effective way to accommodate this change is to effectively lengthen the training week. This plan does just that. I call it a "nine-day week," but what you're really doing is following each hard day of training with two easy days. This means that your hard days will never fall on the same days of the week in consecutive weeks. However, every three weeks (21 days), the cycle resets. More on these 21-day cycles below.
Block periodization: In order to maximize your running fitness at any age, you need to maintain a fairly high volume of training and you need to regularly perform tough, high-intensity workouts. Doing these two things simultaneously is a lot more challenging than maintaining a high training volume without performing regular high-intensity workouts or the obverse. It is especially challenging for runners over 40. Block periodization is a way around this problem. In block periodization, "volume weeks" are separated from "intensity weeks." In this plan specifically, the first two weeks of each three-week cycle are volume weeks, where you train a lot but do very little work at higher intensities. The third week is a an intensity week that features three workouts at higher intensities but sharply reduced overall volume. It's not a traditional practice, but trust me: It works!
Cross-training: It is said that runners have only so many miles in their legs. The reason is the high-impact nature of running. Cross-training in nonimpact aerobic activities such as cycling allows runners over 40 to preserve their legs without sacrificing fitness. In this plan, two of each week's five total workouts are scheduled as nonimpact cardio cross-training sessions. In each instance you have the option of doing a run of the same format instead, but I strongly encourage you to exercise the cross-training option.
Note that the plan uses a five-zone intensity system that is slightly different from the system(s) you may be used to. You will find complete guidelines for this system attached to the first workout of the plan.