The Wikipedia definition of Cheerleading is “an intense physical activity (sometimes a competitive sport) using organized routines, usually ranging from one to three minutes, such as tumbling, dance, jumps, cheers, and stunting to direct spectators of events to cheer on sports teams at games and matches.”
Not all college students are motivated to come to class. The instructor can change some mindsets by demonstrating enthusiasm for the team (i.e. the students in particular) and performing routines that get students excited and make them want to cheer on the team (a.k.a. fellow classmates and maybe even the instructor). Sometimes that cheering takes the form of positive contributions in class and sometimes it is written on course evaluations. If students perceive the class as a game, the are more likely to cheer, and that is something an instructor should consider.
Cheerleaders also try to pump up the team when they are losing. When students are not doing well, the right kind of cheerleading can lead to a win.