Cross-sectional and longitudinal relationship between physical fitness and academic achievement in Japanese adolescents

Although cross-sectional studies regarding the relationship between physical fitness and academic achievement among Japanese children have been previously reported, no longitudinal study has yet been reported for Japanese children. The purpose of this study was to examine the cross-sectional and longitudinal relationships between physical fitness and academic achievement among Japanese adolescents. This cohort study included 1,189 seventh- and ninth-grade students from two schools. The follow-up period was 2 years. A physical fitness test involving eight test items (hand grip, sit-ups, sit and reach, side-to-side jump, 20-m shuttle run, 50-m dash, standing broad jump and handball throwing) was conducted to evaluate the fitness of the participants. Academic achievement in Japanese, mathematics and a foreign language (English) was assessed at baseline and follow-up using cumulative guidance records. Participants were classified into low–low, high–low, low–high, and high–high groups based on physical fitness test results at baseline and follow-up. Compared with the groups showing low fitness levels, those showing high fitness levels for all items of the physical fitness test expect handball throwing had increased odds of showing high academic achievement levels in all three subjects at baseline and/or follow-up compared with the low-fitness groups. Sit-ups and 20-m shuttle run in the high–high and low–high groups were related to higher academic achievement levels at follow-up compared with those in the low–low group for both boys and girls. Therefore, this study suggests that various physical fitness outcomes are positively associated with high academic achievement levels for Japanese children.