Jon, I can’t speak for Ryan, but I’ll quote myself…
…long-term training typically yields 5–15% efficiency improvements in gross economy over months/years…so, a 20% gain in 11 weeks is at the high end.
…and add some emphasis: 20% gains in that time span for anyone except a raw beginner are insane. Like, that result is right on the line between “Holy f***, are you serious?” and “Cool story, bro”…but given that Ryan has been measuring the results in a documented and reliable way, they’re valid. That’s why Ryan being in any kind of untrained state is important: when you’re lower down on the fitness ladder in any way, gains come quick and fast. Doesn’t matter if you’re hiking, running, lifting, getting into bar fights with orcas, whatevs: when you’re starting out, the body has tons of room to improve and it wants to do so…so growth/gain happens fast even with moderate effort. As you go up in fitness, however, it gets harder and harder to improve; eventually you reach physiological and genetic limits, and getting even 0.5% better at your activity or sport in requires incredible effort. So yeah, getting 20% better at hiking after three months isn’t out of reach for a beginner – it’s more likely than not – but for someone that’s been doing it for years and years, it’s a significant gain: they have an existent baseline of fitness that doesn’t easily go away, even when they’re relatively detrained.
Like you, I’m also interested in seeing the actual program…and that’s because I’m a big believer in targeted training for your activity. To an extent, you’re correct that doing a 250-mile hike will probably lead to improvements in caloric efficiency… but it won’t do it to the same level as a targeted and effective training program. You’ll get better at doing everything a 250-mile hike requires – moving efficiently, packing well, hydrating, resting correctly, putting your feet in the correct place on the trail, etc – but spending the same amount of time on doing nothing but energy-efficiency training is gonna absolutely blow that hike out of the water in terms of gains. That’s why marathon runners don’t just run marathons over and over again in order to train: it doesn’t actually help them improve as much as a program that’s designed to improve whatever they’re targeting for improvement.
I found a great example of this in Ed Viesturs’ book, in which he talked about training for his sport (alpine climbing) by doing exactly that: climbing. He thought he was in pretty good shape until a coach took him into the gym, started him on some weights and exercises, and absolutely crushed him with a training regimen. Result: easier climbs in the following season, due to increased strength, joint durability, endurance, etc.
I personally think that most every hiker, climber, backpacker, or outdoors-flavored person could do a lot to increase their fitness and enjoyment of their activities by spending more time actively training for them; myself most of all, and I’m the averagest of Joes. Thus, I’m also very interested in seeing the particulars of Ryan’s training cycle.
Apologies if this was too much of a hijack, but it’s an area of deep interest to me so I wanted to give some further insight as to why I said what I said, earlier.