A "sport" revolved around building cars and going in circles, ovals, whatever. The thing that makes NASCAR such a nonsport is that you use a fucking CAR. There is no specific talent that is required in NASCAR, you are depending on a CAR and you get mechanics to do that for you. So really all you are doing is driving for 6 hours. Woop dee doo, I've driven a car longer. Stop being a wuss.
If NASCAR is a sport then walking is a sport as long as it is in competition. After all you are exerting energy, using technique, and working out to keep in shape. So if you think walking is a sport. Then sure, NASCAR is a sport too.
"Damn, I missed lap 156-167, did I miss anything important?" "No, they are still doing the same thing that they were doing on lap 1-156."