Physical Activity and Global Self-worth in a Longitudinal Study of Children.

Abstract

Physical activity is associated with an array of physical and mental health benefits among children and adolescents. The development of self-worth/self-esteem has been proposed as a mechanism to explain the mental health benefits derived from physical activity. Despite several studies that have analyzed the association between physical activity and self-worth, the results have been inconsistent. It is also uncertain how related physical health measures, such as sedentary behavior, body composition, and fitness, influence the relationship between physical activity and self-worth over time. In the present study, we 1) analyzed if the association between physical activity and self-worth remained constant over time and whether this relationship varied by sex and 2) investigated if changes in body composition and fitness level mediated the relationship between physical activity and self-worth. Data from the Physical Health Activity Study Team were used for this analysis. The Physical Health Activity Study Team is a prospective cohort study that included 2278 children at baseline (ages 9-10 yr) and included eight follow-up contacts for a 4-yr study period. Linear mixed-effects models were used to estimate global self-worth (GSW) over follow-up. Increased physical activity was associated with greater GSW across all waves of data collection, and this relationship did not vary significantly over time or between sexes. Aerobic fitness was positively associated with GSW, whereas body mass index (BMI) was inversely related to GSW. Both aerobic fitness and BMI appeared to mediate the association between physical activity and GSW. Sedentary behavior was not significantly associated with GSW. Physical activity is associated with greater GSW, and this relationship appears to be mediated by BMI and aerobic fitness. These findings reinforce the importance of physical behaviors and physical characteristics in shaping GSW in children.