Yep - thoughts so 
On a side note - i have been reading a Tonn from Your areas Greatest Distance coach - Arthur Lydiard. Even with all them Long runs, they never got Injured. Even the 800guys (is snells old WR still a National Record?)
My best 2 yr of running came after yrs of Aerobic sports, swimming, triathlon, surf life saving.
I remember once running a 10km fun run - then later that same morning, running in a Handicapt 110m sprint race. And ran fast too (13yrs ago, cant remember the times)
Interesting side not is with Lydiards training and the similarities between it and CF training.
The High one session and Low next session.
Max speed work 52wks of the year.
A big part of Lydiards focus is Avoiding La+ work for large parts of the year. Too stressful for the body to handle.
I find it fascinating that he can go to a Country, train the trainers there for a few yrs, and Bam, that country is producing World Class Distance guys/girls.
I know he played an important aspect in shoes. I have even re-laced my shoes accordingly, works great.