One more comment and I'll check out before this turns into another PowerCranks debate...

Any study that simply uses oxygen consumption as it's sole dependent variable to compare the economy or efficiency of one cadence vs another is missing the boat. Some folks use indirect calorimetry to determine anaerobic thresholds or whatever and I'm not sure that's totally valid, but I think indirect calorimetry is directly applicable when comparing the economy of different cadences. With a given rider at a given power output, lower O2 consumption at one cadence vs another is not enough to base any riding economy conclusions on IMHO. When muscles burn glycogen for fuel AND when blood lactate is being buffered, CO2 output rises disproportionately to oxygen consumption (thus raising the respiratory quotient). Lower intake of O2 probably only indicates a more 'economical' effort when comparing one cadence to another if that lowered intake of O2 is NOT accompanied by a disproportionately higher output of CO2. If the respiratory quotient increases, lowered O2 consumption is meaningless when comparing one cadence to another at the same power output (at sub VO2max intensities when O2 consumption is not limiting the effort). If you see a riding economy study that used O2 consumption as its ONLY dependent variable I'd view it with a bit of scepticism.