The Relation Between Physical Fitness Components and Inhibition in Preadolescents: The Role of Shared and Unique Fitness Variance

Previous studies have revealed a positive relation between the specific components of physical fitness and the executive function of inhibition in preadolescence. However, it is not clear whether physical fitness components are related to inhibition independently of each other. In this study, we aim to reveal specific portion of the inhibition variance explained by the shared and by the unique variance of certain aerobic, motor, and muscular fitness tests. For 160 preadolescents (mean age 9.6, SD 0.3), motor fitness (hurdle and crawl test), aerobic fitness (shuttle run 20 m), muscular fitness (bent arm hang), and inhibition (reaction time and accuracy on the Stroop task) measures were acquired. Hierarchical multiple regression was applied to explore the importance of physical fitness and covariates (i.e., age, gender, body mass index, and intelligence) for explaining inhibition. Finally, commonality analysis was performed to reveal the shared and unique contribution of the three physical fitness tests in explaining inhibition. The results revealed that fitness components explained nearly 9% of the inhibition variance. The largest portion of the inhibition variance was explained by the shared fitness variance (38.07%), followed by the unique muscular fitness variance (33.36%), and the shared aerobic and muscular fitness variance (15.62%). Our research showed that the shared fitness variance could be more important than individual fitness components in explaining inhibition. Further to this, we argue that some fitness tests could have embedded inhibition requirements and thus additionally explain inhibition.