Not too sure. Running involves a symbiotic relationship between the organic machine composed of muscles, tendons and ligaments and the ethereal consciouness that desires the sense of fluid motion that running provides. It is an artform that involves the flow of locomotor muscles whilst the agonist, antagonist and synergistic actions of stabilising muscles anonymously endevour to provide the platform for the driving momentum On this basis it is logical that tests such as those detailed in Kelvin Giles' Physical Competence Assessment Manual which test the integrety of the machine should provide a reliable and valid tool in assessing ones fitness to run. However, the greyness of this mortal coil invariably means that some disparity and divergence exists between the art of running and the mechanistic prediction of ability and capacity such that the various assessment tools whilst indicative they fail to be predictive. Therefore runners should always consume the fall out of such analysis with a liberal garnish that allows the contextualisation and interpretation of the tools prediction with common sense and reflection upon what those annoying and noxious signals emenating from those tingling sense organs heralding the coming of compression hosiery.