Association between various sedentary behaviors and academic performance among students in primary and junior-high schools: A cross-sectional study

In Japan, research on how specific types of sedentary behavior are associated with academic performance among school-aged children remains limited. This cross-sectional study investigated the relationship between various sedentary behaviors and academic performance among Japanese children and adolescents. Data were collected in 2023 from 342 primary and 456 junior high school students in Unnan City, Shimane Prefecture. Academic performance was categorized as high or low based on median scores in Japanese and mathematics. Sedentary behaviors were assessed using a questionnaire—including time spent on reading books and newspapers and total recreational screen time, which was calculated from the time spent playing TV games, watching videos or using social networking services (SNS), and using educational tablets at home. Multiple linear regression analyses were conducted, adjusting for factors such as gender, grade, breakfast habits, sleep duration, sports club participation and cram school attendance. Spending <2 hours on TV games, watching videos, or SNS use was significantly associated with higher academic performance across school levels. Conversely, spending <2 hours on total recreational screen time and using educational tablets at home was linked to higher scores among primary students. Reading books was positively associated with Japanese language scores in both groups. Thus, the type of sedentary activity plays a crucial role in the academic outcomes. A shorter duration of recreational screen time and longer duration of educational and literacy-related behaviors were associated with higher academic performance. This study highlights the need for further longitudinal research considering household socioeconomic factors to better understand these associations.