I realize this is a profoundly geeky question, but then I am profoundly geeky, so:
Where did the Randall-Barrows "capacities and powers" model come from?
I.e. was it borrowed from the way energy systems are treated in other sports, was it from sports science research, was it based on observation, did it arise in a burst of pure inspiration in Tom's brain during the umpteen-thousandth lap of the crack training cellar, all of the above, or what?
I'm just curious about how the shift from the previous model (where everything's divided into ARC-level aerobic endurance, power-endurance and strength/power) took place.