The title of this thread is to open a discussion pertaining to the 'science of running', with regard to what is being accomplished in training for particular distances. There is a common theme that in order to be a better runner, one needs to become more "aerobically developed", since race distances beyond 800m use a high percentage of aerobic metabolism.
On this broad topic, possibly there is more confusion than settled science. Nonetheless, if we could come up with some concrete answers, then maybe it would bring clarity to such subjects as:
(1) trading out cross-train volume for running volume (e.g, a triathlete or Nordic skier setting 5k World Road Records); and
(2) optimum overall running volume and overall running intensity for a particular race distance (e.g., Brazier's 30mile/week training).