thanks, have you experience some change in how you feel during mile races and how you have approached them? 3.56 needs a strong run all the way, but I am talkingn about a steady hard effort vs a float with a fast last lap and kicking ability?
Many are born with, develops from young years, and have a good anaerobic and speed base to run really fast. The aerobic ability must be trained. It is genetically given (the theoretic upper limit), but must be developed and does not come for free. I guess focusing so much on strides at least maintains the speed efficiently.
Mile race is primarily aerobic, but needs a fair share of anaerobic work. I think it is somehow obvious that increasing the aerobic capability can improve the mile performance, but not obvious that such a very large milage can make such an impact. I think it also depends on the type of person and how he/she responds to a large mileage. You have obviously managed it and responded well which is not a talent all have.
What comes to mind is the increasing evidence of short term block training being better than a mixed training program. Short (1-2 weeks) blocks with focus on milage, moderate and hard intensities and maintenance of the other two types within a block. The problem with this is the very varying load and injury risk, but the reasoning and results are that a large block stimuli gives larger adaptations than the same amount of smaller and mixed over time. I guess that you have tried a very long block of a large milage stimuli and adapted with a large improvement. The question is if this continues or platous. that might depend upon if your aerobic ability is still not fully developed and can still be increased.
It is well known that so called Fast twitch type runners respond differently than Slow twitch type runners. Within running I do see a bias towards a training philosophy that is best for the ST type and it may be that this kind of reduces the number of FT types that succeeds and the type of training is sort of self-reinforced since we copy the ones succeeding (which is too much to the ST side).
Also the fast twitch muscle fibres need to develop aerobic capabilities as far as they can to excel in the mainly aerobic races. I wonder how efficient milage really is at doing this?