It is hard to train for a thru hike. The magnitude of what you will be doing can not be replicated without walking with heavy packs up and down elevation All Day Long. The best you can do is strengthen your body in preparation. We tried to have a work out schedule but life always seems to get in the way. This is the training patterns we started seeing in our daily lives and adapted to.
Lazy days: (1-2 days/week)
1-3 mile walk with the dog, no weight. Some stretching.
Trying days: (2-4 days/week)
3-5 mile walk or run with 20-30 lb packs. Sometimes with incline (not much elevation, just hills). 2-3 stretching sessions.
Getting it days: (1-3 days/week)
Tring days + home gym workout OR Mountain.
This is by no means perfect, but we have found that it keeps us active even on busy days. The goal is to keep track of each day and not have more than one lazy day per week.
Wonderland, here we come.