Sedentary behavior in relation to selected indicators of movement and characteristics of children in the lower-secondary school

Introduction: Sedentary behavior (SB) of adolescents is often associated with warning signs of emerging civilization diseases and reduced participation in physical activities (PA). Although some studies point out that SB does not necessarily mean avoiding PA, the opinion of the public prevails, that in addition to the time devoted to sitting during school lessons, the time spent watching monitors and screens is constantly increasing at the expense of PA. Our goal was to determine the indicators of the participation of lower-secondary school students in voluntary SB and to relate them to selected characteristics of their movement behavior or evaluate them from the point of view of compliance with medically recommended criteria. Material and Methods: The research was carried out using objective and subjective measurement techniques during a two-year period with pupils of the lower-secondary schools in the Usti Region (N = 512). A record sheet was used to record data on time indicators of participation in physical and SB and basic anthropometric characteristics. Physical activity was monitored by the Yamax SW-700 and SW-800 pedometer for 7 consecutive days, i.e., during regular school days and weekend days. Results: In daily values of time spent in SB, boys surpass girls. Both boys and girls spend more time voluntarily sitting in front of monitors and mobile phones on weekends than on school days (MBW = 162.0 ± 141.4 min. × MBSD = 129.0 ± 109.8 min.; MGW = 133.0 ± 118.1 min. × MGSD = 121.0 ± 110.1 min.). The time values of weekend days show statistical differences between boys and girls (p = 0.02). As pupils age, the time spent on SB increases. In connection with the volume of voluntary SB, neither the mutual relationship of the time of participation in PA (r = -0.006, p = 0.90) nor the volume of locomotor activities (r = -0.058, p = 0.199) was confirmed. Conclusion: The obtained data confirm the increased level of SB in relation to the recommended criteria. In proportion to the reported time of participation in PA or locomotion indicators, it is not sufficiently compensated. However, in many individuals this behavior is well beyond the tolerated recommended values.