"Am I stupid? What is jogging on the spot?!?!"
well first you need to buy a 'spot' . They are usually much less costly than those treadmill things . But a good spot can run around $500. Just put it on the floor and start running without going forward. It can detect your heartrate and loss of fat rate (has sweat sensors in it to detect sweat in the feet). It can also compare your weights over various days.
:-D .... hehehe
Ok seriously , I don't jog on the spot but if your heartrate goes up over that time (once you stop you could tell easily) then it's exercise
I do jog in my apartment ... back and forth .... back and forth LOL