This 20-week marathon training plan is designed for those who have been running regularly at least four times per week for three months and ideally at least one year. It includes easy days, rest days, long runs and marathon-pace runs. The first four weeks are low mileage with four runs per week; the final four weeks also have four runs per week, but with higher overall weekly mileage. At the beginning, the pattern allows for a smoother transition between routine running and formal marathon training. Near the end of training it allows you to ease off of the peak weeks and into the taper with longer endurance-building workouts that simulate what you'll do on race day, and give you the opportunity you need to rest and recover.