How is cardio exercise best described? it gives your heart and lungs a continuous workout. it does not require a continual oxygen supply. it requires short, intense bursts of energy. it lasts only minutes or seconds.

It gives your heart and lungs a continuous workout

when you rub, you also apply pressure, that pressure can urge the poop to come out. i think that when your rubbing, you also might be slightly breaking it up and that can further fill the stomach.