ed to be overweight (Pinkowish, 1998), "despite our nation's intense preoccupation with weight" (Andersen & Others, 1992, p. 938). The main risk of not exercising is heart disease, and adults who engage in physical activity and who are not overweight generally have less heart disease (Powell & Others, 1987). The heart-disease risk of obesity and "sedentary lifestyles," including watching television instead of exercising, is the reason that experts say adolescent girls should be encouraged to do vigorous activity (Troiano & Others, 1995). However, obesity is increasing, not decreasing, in the population as a whole. In other words, the girls are not taking good medical or exercise advice. Recent studies of boys and girls from age 8 to age 16 have showed that as a group girls do not exercise as much as boys. As girls get further into their teens, their level of physical activity may decline. One important study reported:
[O]nly 65% of girls aged 14 through 16 years reported 3 or more bouts of vigorous activity per week, whereas 86% of age-matched boys achieved this level. Few boys or girls reported 1 or less bouts of vigorous activity per week, with the exception of 20.1% of 14- to 16-year-old girls reporting this level of inactivity. Further analyses (data not shown) revealed that 8.7% of the 14- to 16-year-old girls reported less than 1 bout of vigorous activity per week (Andersen & Others, 1992, p. 940).
On the other hand, female adolescents and young adults make up about 90% of the eating-disordered population (Eating, 1998). Both obesity and eating disorders, which can have negative health effects, have been connected to the fact that "adolescent females are generally more negative about their bodies and are concerned with physical beauty and maintaining an ideal, thin shape (as identified by media and societal images" (Rhea, 1998, p. 27). In general, worried about their appearance to others, girls consider their physical appear...