soccerxc wrote:
He was running anything from the 4x400 to the indoor mile, so it doesn’t seem ludicrous as he’s not a 5k/10k specialist
Even 1500 specialists like Jakob Ingebrigtsen or Marcin Lewandowski run 100 mpw, in base phase 110 mpw. Lewandowski has 47s 400m speed and closed 1500 races extremely fast, so it's not like the high mileage "ruins" his speed.
This seems to be more of a case of bad coaching/lack of work ethic, rather than optimizing 800-1600 times.
Brazier as example why low mileage is good for 800+1500 is also a pretty bad example, since he only ran 3:37 off 1:42 800m. Lewandowski ran 3:31 off 1:43 800m, doing 2-3x the mileage. This further proves that if you want to be a good miler, you NEED to get your mileage up. Brazier is with no doubt one of the most talented guys in the world, but the fact that despite his talent he can only run 3:37 due to the low mileage he is doing tells us enough.
Last, I want to mention that recent research has shown, the mile as event is between 75-84% aerobic (depending on speed of runner, and muscle fiber distribution). Spencer is talented, he has a high, natural VO2MAX but this low mileage non-sense is probably holding him back from what he could achieve in the mile if he got his 10k time to sub 30 and get stronger aerobically.