LAUSR

Abstract Background Few studies with children in Asian countries, especially in Japan, have examined the relationship between walking to/from school and physical activity by segments of the day. Therefore, the present study examined the associations between walking to/from school with physical activity before school, after school, and during the entire day in a sample with a high proportion of Japanese children who walk to/from school. Methods A total of 119 participants (10.4 ± 1.3 years old) were investigated regarding their mode and length of school commute and physical activity. Step counts, sedentary time (ST), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) were measured using an ActiGraph GT9X Link accelerometer. The associations between time walking to/from school and physical activity were analyzed using the Spearman correlation coefficient. A receiver-operating characteristic analysis was used to identify the threshold of the time spent walking to/from school that is necessary to meet the physical activity guideline (MVPA ≥ 60 min/day). Results The results showed that 90.8% and 89.9% of students walked to/from school, respectively. The segments of before school, after school, before and after school, and during the entire day demonstrated significant low to high (r = 0.20–0.86) correlations between the time spent walking to/from school and step counts, ST, LPA, and MVPA. Our study showed that spending ≥45 min walking to/from school is important for meeting the physical activity recommendations. Conclusions This study provides important evidence for the promotion of walking to/from school in the future. In addition, our results also suggested that children with relatively short commuting time to school need to be more physically active in daily life situations.