Does anyone know how the C2 actually measures the energy expended while rowing? Does the computer average the number of revolutions of the flywheel over time, then calculating by some known quantity based on the weight/friction of turning the wheel? Or does it measure changes in angular velocity of the wheel? This would come in to play when trying to maximize certain scores on the erg. (Distance vs. wattage vs. calories).

At this point in my life, my rowing is confined to ergs. So this question stems from "bro science" advice from a Crossfit gym. The popular wisdom there and on the internet is that, when rowing for meters, choose a higher SPM rate to keep the wheel spinning. But when rowing for a set number of calories, go with a low SPM and let the wheel slow between catches. In today's workout, we had intervals that included "max calories in 1 minute" on the erg. Some of the guys insisted that they racked up more calories at 1250 cal/hr by pulling hard at 24 SPM than I did at 1600 cal/hr at 36 SPM. I don't see how that could be possible. Hence my question about the actual mechanics of how the C2 gets it measurements.