26.2 kilometers (or 16.2 miles) at marathon goal pace run on a course that represents the race for which you are training. If an athlete is preparing for the hilly New York City Marathon, it is important to execute it on a similar course and not one that resembles, say, the flat Chicago Marathon. Some of the “magical” qualities of the simulation are lost if the right terrain can’t be located. Besides providing a significant effort run at goal pace, the idea of this workout is to let you visualize the course, develop a plan for racing and get a feel for what you want to do on race day.
Including warm-up and cool-down, this workout tops out around 20 miles, and therefore should be approached with caution. If an athlete is logging low mileage, attempting this workout is a flat-out bad idea. Runners should try this only if they are putting in at least 75-100 miles per week and also have a course on which to properly simulate the goal race.
The Simulator is generally done about four weeks prior to the goal marathon and is the first in a series of difficult workouts.
Excerpted with permission from Hansons Marathon Method, 2nd Edition
(Velo Press, 2016)