The book harnesses research in a way that defied my expectations and made an impression on me. Though I have no interest in being an "uphill athlete," I found many insights in reading such a niche document. I came at this from the perspective of a middle distance runner who can't understand competitive trail running, nevermind the other stuff. Primarily, I found the focus on Z1 and Z2 training to be interesting. But, also, as someone who cross trains a lot, the structured training plans for all types of activity (including SkiErg) were useful.