Physical activity, motor skills and sedentary time in China adolescents: A cross-lagged analysis

Background and study Aim: Physical activity, motor skills and sedentary time are important to adolescents' development, the longitudinal relationship between them is unclear. The aim of this study was knowledge about the associations between moderate to vigorous physical activity (MVPA), sedentary time, motor skills in China adolescents. We hypothesize that MVPA is positively linked with motor skills and negatively with sedentary time. Material and Methods: A total of 124 participants (64 boys, age 12.48 +/- 0.21 years) completed two tests. Accelerometer was used to measure MVPA and sedentary time. Movement Assessment Battery for children, Second Edition (MABC-2) was used to measure motor skills. Cross-lagged structural equation modelling was conducted to evaluate the associations between MVPA, sedentary time, and motor skills at 7(th )grade and 8(th) grade students. Results: (1) MVPA at both time points was negatively associated with sedentary time in 7(th) grade (r = -0.311 and -0.610); (2) there was a significant positive correlation between MVPA in 7(th) grade and object control skills at both time points (r = 0.306 and 0.444); (3) sedentary time at both time points was negatively associated with the object control skills at the 8(th) grade (r = -0.365 to 0.452). The cross-lagged analysis showed that: (4) the MVPA in 7(th )grade was positively correlated with object control skills in 8th grade (beta = 0.27, p = 0.003); (5) balance skills in 7(th) grade were positively associated with object control skills in 8th grade (beta = 0.15, p = 0.036). Conclusions: Object control skills are positively associated with MVPA, and negatively associated with sedentary time, reducing sedentary time and increasing MVPA are essential to promote the development of adolescents' object control skills.