I am by no means educated in physical fitness or health.
Besides the difference of "exercising", what is the difference between having a high heart rate from doing a cardio workout versus having a high heart rate from emotions?
Confrontation, Fear, Nervousness ... These emotions elicit a response from the body that increases heart rate often for an extended period of time.
Could being pissed off and storming around the room for a half hour be a workout equivalent of walking around the block?