Promotion of independent physical activity (PA) is indispensable for resolution of various health issues in childhood. Recently in Japan, however, concern has been raised about decreased levels of independent PA among children. The present study was therefore conducted to examine the current situation of independent PA in elementary school students during school recess, and the factors affecting it. The study participants were 1,059 3rd grade to 6th grade children (536 boys and 523 girls) attending 7 elementary schools in Japan. Research was conducted at participating elementary schools between October and November 2015. All the data were collected using an original questionnaire that asked about living conditions, independent PA during recesses, the school environment, and other issues. The reported rates of independent PA during the lunch recess were in excess of 50% (50.8-62.6%) , suggesting that a relatively large proportion of time was secured for this purpose regardless of gender and school grade. However, the rates for before-class recess (18.4-56.4%) and morning recess (22.6-68.3%) were not particularly high, although there were large variations according to gender and school grade. With regard to before-class recess, “gender” and “desired place to play” were extracted as factors affecting the occurrence of independent PA. Similarly, for morning recess, “gender”, “school grade”, “desired place to play”, and “desired equipment for play”, and for lunch recess, “desired equipment for play”, “classroom floor”, and “likes and dislikes for PA” were extracted as factors determining the occurrence of independent PA. These findings suggest that improvement of physical environmental factors could promote independent PA of children during school recesses.

The purpose of this study was to examine levels of physical activity and its correlation with neighborhood environment among children living in the 2011 Great Eastern Japan Earthquake and Tsunami affected area. A serial cross-sectional data set was developed for this study by conducting two surveys at approximately 1 year (N=209) and 4 years (N=142) after the occurrence of the earthquake and tsunami. At each survey point, assessment of physical activity for fourth- through sixth-grade schoolchildren was performed using a self-administered questionnaire. The questionnaire also included questions on sex, age, grade, height, and weight. An independent t-test showed that the average sitting time on a weekday at the 4-year survey point was lower than that at the 1-year survey-point (t (296) =3.9, p<0.001, effect size (d) =0.22) . Analysis using the quantification theory type I revealed that neighborhood environment variables were not significantly associated with sitting time at the 4-year survey point. However, at the 1-year survey point, presence of sidewalks and residential density were significantly associated with sitting time on weekdays (β=−0.18, 95% confidence interval [CI] : −0.21 to −0.01, p=0.03) and sitting time on weekdays (β=−0.28, 95% CI:−0.27 to −0.08, p<0.001) and weekends (β=−0.20, 95% CI:−0.22 to −0.02, p=0.02) , respectively. Moreover, a binary logistic analysis showed that high intensity physical activity such as exercise and sport, was not associated with the neighborhood environment variables at the 4-year survey point, whereas access to recreational facilities (odds ratio=2.74, 95% CI:1.24 to 6.02, p=0.01) significantly correlated with exercise and sports at the 1-year survey point. These results suggest that environmental restoration possibly improved physical activity among the children.