not Luv2run wrote:
1, Yes, lots of reasons like those.
2, And his coach John Kellogg gave him confidence to keep improving, which takes thousands of miles and lots of quality workouts.
3, What else happened? He became more energy efficient.
4, Maybe, but 1.5% is often referred to as being statistically insignificant in ex phys research. And Luv2run has a fixation on concepts which ignore calorimetry. And you don't understand calorimetry either. Nor, it seems do a very high proportion of ex phys researchers and peer reviewers of the endless stream of papers proposing enhancements which circumvent the laws of physics.
5, I'm trying to explain something very simple here, but after 15 years, you're still not grasping it.
5, It looks like you are trying to explain "how" -- the question here is "how much".
With respect to calorimetry, I understand heat accumulation and the related heat dissipation are factors that can limit performance. Besides efficiency, something as simple as losing weight can improve both reduce heat generation and increase heat dissipation.
What you are trying to explain is indeed something very simple. I prefer a more complex Endurance Performance Model from long time Exercise Physiologist Stephen Seiler. It includes factors like efficiency and psychology, but also many more internal and external factors. As complex as it is, Seiler says it is still over-simplified, listing 8 more factors that could be added. Performance limiters like heat accumulation and dissipation were not included (directly), but easily could be.
Once I stumbled upon his Endurance Performance Model, and his related "Time Course of Training Adaptations" (a simple representative graph and explanation of VO2max + Lactate Threshold + Efficiency timeline of performance gains), I closed the "physiology" chapter and decided it was better to focus my energy on more pragmatic topics like proven effective training methods, and running results as measured by a stopwatch, regardless of the cause, or complex combination of causes.
Luv2run posted a link to a 2008 study by Stray-Gundersen and Levine. I have no strong opinions about Luv2run, but I do have a high opinion of Stray-Gundersen and Levine. I have often linked to an earlier 1997 study by these same authors, looking at high-low performance, which included a sea-level performance control phase (where everyone improved at sea-level as they got used to the study methods) , a sea-level control group, a high-low altitude training group, and a high-high altitude training group composed of men and women. It is hard for me to ignore the significant altitude related changes in oxygen, lactate, blood, ventilation, and time-trial performance values they observed, which don't seem to be easily explained by efficiency and calorimetry alone -- but you are welcome to try.