Physical Activity and Physical Fitness in Adolescents after the COVID-19 Lockdown and One Year Afterward.

The purpose of this study was to analyze the changes in physical activity and physical fitness between the beginning of the first academic year after a confinement (November 2020) and the beginning of the second academic year after a confinement ("new normality": November 2021) in a cohort of adolescents. Moreover, the evolution of physical fitness after controlling for physical activity was examined. A total of 687 students ( = 15.35, = 1.677) from a high school located in a rural town in northern Spain gave information on their physical activity (PA) levels in two different periods. Linear mixed models were used to examine these changes. The results indicated that vigorous physical activity (VPA) and the metabolic equivalent of task (MET) significantly increased between the two periods. A growth tendency of several components of fitness (upper body power, strength endurance, cardiovascular fitness, flexibility, and eye-hand coordination) was also observed. Finally, the results indicated that belonging to a sports club and getting involved in more VPA better explained the development in cardiovascular and muscle fitness between the two time points. Thus, the results of this study highlighted the relevance of membership in a sports club and vigorous PA in order to mitigate the potential negative effect of social distancing measures on physical fitness.