Participation in vigorous sports, not moderate sports, is positively associated with cardiorespiratory fitness among adolescent girls.

BACKGROUND: There is controversy regarding whether moderately-intense sports can improve physical fitness, which declines throughout adolescence among girls. The objective was to estimate the association between moderate and vigorous sports participation and cardiorespiratory fitness in a racially diverse sample of adolescent girls. METHODS: Cardiorespiratory fitness was measured using a modified physical work capacity test in 1029 eighth-grade girls participating in the Trial of Activity for Adolescent Girls. Girls reported sports in which they participated in the last year on an organized activity questionnaire. Using general linear mixed models, the study regressed absolute and relative fitness on the number of vigorous and moderate sports in which girls participated, race/ethnicity, age, treatment group, fat mass, fat-free mass, and an interaction between race and fat-free mass. RESULTS: The number of vigorous sports in which girls participated was positively associated with absolute fitness (ß = 10.20, P = .04) and relative fitness (ß = 0.17, P = .04). Associations were reduced, but not eliminated, after controlling for MET-weighted MVPA. Participation in moderate sports was not associated with either fitness measure. CONCLUSIONS: Vigorous sports participation is positively associated with cardiorespiratory fitness. Future longitudinal research should analyze whether promoting vigorous sports at an early age can prevent age-related declines in cardiorespiratory fitness among adolescent girls.

Past-year sports participation, current physical activity, and fitness in urban adolescent girls.

BACKGROUND: This study examined associations between sports participation, physical activity, fitness level, and body mass index in ninth-grade girls. METHODS: Data were analyzed for 221 participants who completed sports participation and physical activity recall questionnaires, an aerobic step test, and height and weight measurement. RESULTS: On average, participants had low physical activity levels, and many were overweight or obese (47%). About half participated in at least one organized sport in the previous year. Sports participants had higher current estimated energy expenditure compared with non-sports participants (P=.0007). Those who participated on at least two teams were more likely to complete the three-stage step test without reaching their target heart rate than those who did not participate on any teams (P<.03). Past sports participation was positively associated with current physical activity and fitness levels. CONCLUSION: Urban adolescent girls who participate in sports have increased energy expenditure and higher fitness levels, indicating sports as a potential strategy to improve physical activity and health in this population.

Effects of a life skills intervention for increasing physical activity in adolescent girls.

BACKGROUND: Although adolescence is a time when physical activity levels decline, few interventions have targeted high school-aged girls in the school setting. OBJECTIVE: To evaluate the effects of a life skills-oriented physical activity intervention for increasing overall physical activity in high school-aged girls. DESIGN: Randomized controlled trial. SETTING: Baltimore magnet high school. PARTICIPANTS: A total of 221 ninth-grade girls, 83.0% of whom were African American. Intervention Participants were randomized to an 8-month physical intervention conducted in physical education class or to a standard physical education class (control). MAIN OUTCOME MEASURES: Self-reported estimated daily energy expenditure (physical activity), self-reported sedentary activities (television viewing and computer or Internet use), cardiorespiratory fitness, and selected cardiovascular disease risk factors. RESULTS: Intervention classes spent 46.9% of physical education class time in moderate to vigorous activity compared with 30.5% of time for control classes (P<.001). There were no significant between-treatment group differences for mean daily energy expenditure (P = .93), moderate-intensity energy expenditure (P = .77), or hard to very hard energy expenditure (P = .69). The proportion of participants who spent 3 or more hours viewing television during school days declined from 22.3% to 17.0% in the intervention group, but remained at 26.7% for the control group (P = .03). Both groups improved their cardiorespiratory fitness (P<.001). CONCLUSION: A life skills-oriented physical education curriculum may need to be combined with other approaches to increase the magnitude of effects on physical activity behavior in predominantly African American high school-aged girls.