At a peripheral level, the aim I would say is to maximise aerobic muscle fiber charateristics, maximising the mitochondrial reticulum and capillarisation in as many muscle fibers as possible.
Ok I am with you.
In my training I have the best results for Olympic distance triathons with a combination of B and C. BTW I am probably not a great reference as I am traditionally a solid middle of the age group pack racer.
I will have 1 long bike a week, 1 long swim a week and 1 long run every 3 weeks with interval work for the run and swim interspersed throughout the week. The bike I will usually do 1 shorter session at a higher steady state mixed in with intervals.
Basically if you have any suggestions or want someone to try a different training methodology let me know as I am starting my race prep for my "A" race in September.
What we think, or what we know, or what we believe, is in the end, of little consequence. The only thing of consequence is what we do. -John Ruskin