What workout elements are essential to training for a 5 day hike?
I would suggest doing some BOSU/disc work, or training on any other type of “unstable” surfaces to prepare you for the terrain that may be involved in your hike:
I would alternate between endurance training vs. strength training. I would also include interval work as a part of your cardio training, really mixing things up.
Upper body work such as pushups, chin ups, TRX, planks, step ups etc. would be great since you’ll be carrying load on yourself!
Great idea about adding weight to your pack, it’s a good thing to adapt to this prior to going out into the wilderness and not being able to carry your belongings!