Periodization

I began my periodization training for 8-hour endurance racing today.  I rode for nearly 5 hours southwest of Weston Canyon in the Clarkston Mountains on the Caribou National Forest.  No, there are no caribou there.  Periodization training?  It's specific training that usually lasts for about 6 weeks or more leading up to a specific event.  In other words, I need to slowly increase the length of my rides if I'm going to do an 8 hour race.  The event?  It's next Saturday.  So much for periodization training.  It's more like off the couch with no training at all.