Comparison of national trends in physical activity among adolescents before and during the COVID-19 pandemic: A nationally representative serial study in South Korea.

Background: The COVID-19 pandemic has dramatically altered daily routines and lifestyle behaviors worldwide, potentially significantly impacting physical activity levels, especially among adolescents. Understanding these changes is crucial for developing targeted interventions to promote health and well-being in this vulnerable population. This paper will explore longitudinal trends of physical activities (PA) in Korean adolescents, focusing on changes between the pre and late-COVID-19 pandemic periods.

Methods: The data used were from the Korea Youth Risk Behavior Web-Based Survey for consecutive years from 2009 to 2022. In this study, we have separated data into the pre-COVID-19 pandemic (2009-2019) and the pandemic. Following the World Health Organization (WHO)'s guideline, we analyzed adolescent self-reported moderate-to-vigorous physical activity (MVPA).

Results: A total of 890,941 adolescents, people aged between 12 and 18 years old. The 14-year trends in MVPA showed an upward trend both before the pandemic (β, 0.005; 95 % confidence interval [CI], 0.004-0.005) and during the pandemic (β, 0.004; 0.002-0.006). Furthermore, the prevalence of MVPA recovered/increased in 2022 (5.61 % in 2020, 5.22 % in 2021, and 6.34 % in 2022). Similar to the MVPA patterns, the mean metabolic equivalent task (MET) score increased during before the pandemic (β, 15.392; 12.523-18.261) and during the pandemic (β, 49.518; 41.948-57.088). However, unlike MVPA patterns, the MET slope changed positively (β_diff, 34.126; 26.031-42.221).

Conclusion: Present findings suggest that Korean adolescents achieving the recommended PA levels by the WHO remained steady despite the pandemic. This stability in PA levels during a significant disruption (i.e. the COVID-19 pandemic) is noteworthy and warrants further investigation into the factors that may have contributed to this resilience, including potential influences from various societal and environmental elements.