Cardiorespiratory fitness in urban adolescent girls: associations with race and pubertal status

Cardiorespiratory fitness affords health benefits to youth. Among females, weight-relative fitness declines during puberty and is lower among African American (AA) than Caucasian girls. Data indicate racial differences in pubertal timing and tempo, yet the interactive influence of puberty and race on fitness, and the role of physical activity (PA) in these associations have not been examined. Thus, independent and interactive associations of race and pubertal development with fitness in adolescent girls, controlling for PA were examined. Girls in grades 5-8 (n=1011; Caucasian=25.2%, AA=52.3%, Other Race group=22.5%) completed the Pubertal Development Scale (pubertal stage assessment) and Fitnessgram (R) Progressive Aerobic Cardiovascular Endurance Run (PACER) test (cardiorespiratory fitness assessment). PA was assessed by accelerometry. Bivariate and multivariate analyses were used to examine associations among race, pubertal stage and fitness, controlling for vigorous PA, AA, and pubertally advanced girls demonstrated lower fitness than Caucasian and less mature counterparts. Puberty and race remained significantly associated with fitness after controlling for vigorous PA. The interaction effect of race and puberty on fitness was non-significant. The pubertal influence on fitness is observed among AA adolescents. Associations between fitness and race/puberty appear to be independent of each other and vigorous PA. Pubertally advanced AA girls represent a priority group for fitness interventions.