Cheerleading
A recreational activity and sometime competitive sport involving organised routines including elements of dance and gymnastics to encourage crowds to cheer on sports teams. It is most popular in the United States.
Evolving in (all-male) colleges in the late 19th and early 20th centuries purely as attempts to encourage crowds at their sporting competitions to cheer, as time progressed the activity spread and became largely a female activity. Organised cheerleading contests were formed, high schools around the country started forming cheerleading squads. Today cheerleading competitions are ubuiqitous amongst many American public schools and universities (though by no means universal).
Cheerleading has a rather mixed reputation as a serious athletic endeavour. Cheerleaders are stereotyped in thousands of television shows and movies as vacuous, unintelligent, bitchy, attractive, and sexually available (particularly to members of the sporting teams they cheer on), and the routines regarded as opportunities to expose and highlight their attractive bodies. In its defence, it is doubtful whether any of cheerleading's detractors have ever tried to perform a routine.