Originally Posted by Carbonfiberboy

I think the OP is curious, is all. It's a good question. Those who've replied about HR must have thought they were in some different thread. Nothing in this thread about HR or calorie calculators, etc. Too many BFers give their standard response without reading that to which they are responding.

Originally Posted by SapInMyBlood

So I recently discovered how power meters / heart rate monitors are able to measure the able of work done (in kJ) and then spit out a fairly accurate figure for the amount of calories consumed in order to equate said effort (Usually equivalent to calories consumed equal to kJ of work done, units staying the same..).