Motor and cognitive development follow similar timetables across childhood (Piaget, 1964). Relationships between both are widely accepted (van der Fels et al., 2015) and partially explained by the demands motor tasks place on executive functions (EF) as well as by neurophysiological changes through exercise (Tomporowski et al., 2008). However, longitudinal evidence on parallel or reciprocal relationships is lacking. Moreover, the constructs physical fitness (PF) and motor competence (MC) have not been considered separately with regard to EF. Thus, this study examined the cross-lagged relationships between EF and PF as well as between EF and MC in primary-school children.
N=198 children (mean age=8.08 ± 1.0, 50% male) 2017 and 12 months later completed two motor tests: the FitnessGram (PACER, broad jump, 20m sprint; FitnessGram, 2016) assessed physical fitness while the TGMD-3 (Ulrich, 2018) assessed MC (locomotion, object control). EF were assessed by the Flanker Task (inhibition) and N-Back Test (working memory). Structural equation modelling (CFI>.95, IFI scaled>.95, SRMR<.05) revealed relative stability for PACER (b = .55), broad jump (b = .75), sprint (b=.58), locomotion (b=.50), and object-control (b=.62, all p<.001). EF showed moderate stability (inhibition: b=.31, p<.01; working memory: b=.31, p<.001). Cross-lagged relationships were found for locomotion (b=.20, p<.05) and object control (b=.21, p<.05) predicting working memory.
Results support that PF and MC are more stable across childhood than EF and show that the level of MC predicts working memory performance one year later. The present findings pinpoint the necessity to distinguish between MC and PF in cognitive development during childhood. More longitudinal research to explain differences and underlying mechanisms is needed. Implications for research and physical education will be discussed.