I found some stuff on PAVVO (charts, paces, philosophy,etc.) online. I dont have time right now (on a lunch break) I can post them later.
The comment on muscle contraction / myosin head.... uh.. even when you are walking these myosin heads on your muscle fibers are working. Its not about areobic/anaerobic respiration. It is if there is available ATP for contraction. Here is a graphic on the contraction (
www.getbodysmart.com/ap/muscletissue/contraction/m....) press play.
Anyway, in connecting the myosin head talk, the more intense the contraction, more fibers are used. What I understand from PAVVO, is that there is a lot of intense training. More fibers get recruited and trained.
Yes, H.S. runners improve on PAVVO as anyone would. What limits performance is maximal oxygen consumption or I should say velocity at max O2. The PAVVO system trains the vo2max / lactate threshold systems.
I think the reason they dont improve in college is because college coaches stress the same thing. VO2max/ and LT work. Its already optimally trained. What should be stressed is endurance to level out performances.