| Actually in brief without explaining all the science exactly, by using on-off dynamics (measuring heart rate responses many times per second to get the measure at beginning and end of an exercise) there is a calculation of %VO2 max utilization that is made--which is an intensity measure that CAN differ from heart rate intensity (if you only look at % Max heart rate) and causes EPOC accumulation at different rate--not straight line.
Not all heart rate monitors do this! |