Here is part of the script for tonight's episode. My dad works at MTV studios and he's an editor so he got me a copy of the script so here it goes.
Ext. Kids' football PRACTICE FIELD -- DAY
A bunch of boys are on the field doing jumping jacks (or some other exercise we can actually animate our boys doing)
Boys 21! 22! 23! 24! 25! (keep going to go under the rest)
Reverse to montrer that Cartman is sitting on a little chair in his football outfit sipping a water. Behind him we can see some parents in the bleachers. The coach is standing suivant to Cartman, watching practice, and there's football practice equipment...