This has been a constant debate, whether cheerleading is a sport or not. There is very valid evidence for both sides of the argument.
Cheerleaders are commonly seen on the sidelines at football and basketball games supporting their teams. Fans just see them as other people supporting their team.
However, the cheerleaders have to go through rigorous training and practice all the time to perfect the routines displayed at games.
Along with cheering on the sidelines at games, most cheerleading squads participate in heated competitions to show their athleticism.
Although it is not officially defined as a sport by the NCAA or high school associations, it obviously should be for many different reasons.