A Longitudinal Analysis of Changes in Adolescents' Physical Activity

Objectives The purpose of this study is to examine the trend of changes in adolescents' physical activity using data on adolescents' physical activity over the past five years from the first year of middle school to the second year of high school. In addition, it is intended to provide basic data for improving healthy physical activity by checking how the participation time of adolescent survey participants who experienced the COVID-19 epidemic has changed. Methods This is a secondary analysis study using data from the ‘Korean Children and Youth Panel Survey 2018’. Analyses were conducted using descriptive statistics, frequency analysis, correlation analysis, and latent growth model analysis with the SPSS/AMOS 25 program. Results First, The average physical activity time of adolescents decreased each year from middle school to high school, but remained at similar levels during the first and second years of high school. Second, The physical activity during the first and second years of middle school showed the highest positive correlation, while the correlation between the first year of middle school and the second year of high school was the lowest. Third, the latent growth model analysis showed that a nonlinear change model was more appropriate than a linear change model for the trends in adolescent physical activity. Specifically, the decrease in average physical activity time was pronounced during the middle school years and became more gradual during the high school years. Lastly, the changes in physical activity before and after the COVID-19 pandemic were significant, and the reduced levels of physical activity persisted thereafter. Conclusions Changes in adolescent physical activity were related to transitions between school levels, with particularly rapid changes observed before and after the COVID-19 pandemic. This highlights the need for appropriate encouragement of physical activity tailored to the growth stages of adolescents and active measures to enhance physical activity levels that declined after the COVID-19 pandemic.