Sporty girls from the outside often have a great deal of trouble adjusting to Brentwood life. A fit, trim figure is certainly valued. Exercising in an appropriate way (e.g. aerobic classes) for beauty and to strengthen the body for child birth and child rearing is accepted and expected. However, in Brentwood girls are not allowed to play sports.
Participating in sports has a very negative effect on girls. It encourages unladylike behavior such as grunting and shouting. It also makes girls accustomed to being the center of attention and takes them out of their natural support role. Just as the pursuit of careers distracts girls from the outside from their true purpose of serving men, so too does the futile pursuit of excellence on the sports field--excellence that will never measure up to that of men.
Cheerleading, however, is considered to be a very healthy activity. The girls are kept very fit both through the strict training regime and by an atmosphere of constant peer pressure to remain thin, toned, and as pretty as possible. Furthermore, while they are getting their exercise they are supporting and encouraging men. These benefits are often lost on the self-centered, strong-willed sporty girl.
Before moving to Brentwood, Amanda had been a "star" basketball player. It was bad enough that she wasn't allowed to play anymore, she had been signed her up for cheerleading. So, she'd been forced to trade her unflattering shorts and jersey for a fetching cheerleader uniform, and the old basketball for bright, cheerful pom poms.