Absolutely it should be considered a sport. I do not watch NASCAR. I hate NASCAR. I also was one of those people who thought it wasn't a sport. And then I was challenged by a friend who does watch it. He challenged me to read what the drivers endure each race, and tell him it wasn't a sport.
What do they go through? Well to start, they are subjected to inside temperatures that approach 120 degrees fahrenheit for the duration of the race. While wearing a full faced helmet. While wearing a full length protective suit. Basically, they sit in a fucking sauna for three plus hours a time, losing around 10 lbs of water in sweat. Every week. You have to be physically fit for your body to tolerate dropping and adding that much water constantly.
Then, you have to consider the stress. While they are roasting in their mobile sauna, they are subjected to the stress on their bodies as a result of not only driving at 180 plus mph, which certainly pumps adrenaline through them, but with the mental concentration required to not only drive but to avoid other drivers. They have to have a high amount of stamina, as well as being both mentally and physically tough. They are athletes. They have to be. The physical and mental exertion would require it.
They are tough sons of bitches.