Leisure-time physical activity, sedentary behavior, and fitness of high school girls

Abstract

Background: Childhood physical inactivity may exacerbate other behaviorally linked cardiovascular disease risk factors such as hypertension, and hyperlipidemia, which have been associated with subsequent morbidity and mortality later in life. Evidence suggests that physical activity as adults is related to their exercise patterns as children. Methods: Television watching and Internet use time were evaluated for one week, and their relationships to various physical fitness parameters among 129 high school girls were assessed. Leisure-time physical activity, quantified by a 21-day physical activity diary and a compendium of physical activities with metabolic equivalent (MET) intensities, and attitudinal belief to leisure-time physical activity were compared to all the aforementioned variables. Results: No significant correlations were found between television watching time or Internet use time with body mass index, one-mile run time, and three different operational definitions of leisure-time physical activity. One-mile run time correlated moderately with body mass index and negatively with leisure-time physical activity. Caloric expenditure during lei-sure-time physical activity was weakly related to body mass index. Attitudinal belief to leisure-time physical activity correlated significantly with leisure-time physical activity, weekly caloric expenditure, and inversely with one-mile run time. The foremost predictor of mile-run time was body mass index, followed by attitudinal belief to leisure-time physical activity and leisure-time physical activity. Conclusions: Leisure-time physical activity and attitudinal belief to leisure-time physical activity are significantly (and inversely) associated with physical fitness only when expressed by an actual performance measure, but not when represented by the sum of the skinfold measurements, body fat, or body mass index. Physical fitness is unrelated to Internet use time or television watching time. Furthermore, since these sedentary behaviors are unrelated to leisure-time physical activity, yet positively correlated with each other, it is suggested that time spent watching television or on the Internet does not occur at the expense of leisure-time physical activity.