Just read the RW interview with Hall. Oddly enough, the one thing that really stuck out to me was Hall's claim that only runs for 30 minutes at a time these days. That's exactly the amount Alberto Salazar runs today (although I can't find the interview where I read that).
The similarities between Hall and Salazar certainly don't stop there. In fact, their careers followed nearly the same success trajectory:
1) Overtraining through youth and college years
2) Responding to excessive training in their early to mid 20s, having world-class success
3) Begin experiencing cumulative fatigue in their late 20s
4) Finding temporary cures to the fatigue, only to have it come back stronger
5) Leaving the sport in a tired, unhealthy state that prevents them from running longer than 30 minutes
Alan Webb has followed a similar career path as well, although there are a few variations in his timeline.
So this begs the question: What exactly is happening to these guys? Is "cellular damage" a real thing? Are they developing mechanisms that prevent them from running beyond a certain point because their bodies become efficient at recognizing fatigue and the damage it causes?
I'm really curious to understand the science behind this all. Pipe in if you have a theory, and please keep the discussion on topic.