Now this is not my area of expertise but it has got my interest. Swimming may also help on days where you are just sore by taking a little bit off the joints.

Flags or anyone else familiar with diving and elk hunting can chime in. As a freediver I have done apnea training, could apnea training possibly help out in the high altitude scenario in becoming more efficient at using low oxygen levels? Think I found an answer: http://www.matthewdthornton.com/ApneaTraining.html