This study is the first to investigate associations between 24-hour activity behaviours and motor competence using a hybrid-based (both process- and product-based outcomes) measure that assesses proficiency in fundamental, combined, and complex movement skills. It adds to previous compositional analysis studies(10–13), by extending to children and adolescents, while stratifying by sex. In all children and adolescents, we found that activity composition was significantly associated with DC overall, process, and time scores. Among primary school participants, activity composition was associated with time score only, while in secondary school participants it was associated with overall, process, and product scores. Overall, relative to other activity behaviours, MVPA had the greatest association with motor competence outcomes. The largest positive predicted differences in motor competence outcomes occurred when MVPA replaced LPA.
Congruent with previous systematic review evidence supporting positive isolated associations between PA levels and motor competence(2, 7), these findings reinforce the key role of MVPA for children’s and adolescents’ motor competence. They also support previous compositional studies examining associations between activity behaviours and motor competence in preschool and primary school children(10, 11). These showed that reallocating time to MVPA, elicited the largest positive predicted change in overall motor competence scores(10, 11). However, contrary to our findings, another compositional study found that relocating time to LPA or sleep, at the expense of ST, was associated with positive differences in motor competence in primary school children from a low socioeconomic status area(12). Nevertheless, despite one recent systematic review finding no evidence for an association between PA and motor competence(3), our findings, as well as others(10, 11) provide empirical evidence that MVPA, relative to other behaviours is associated with motor competence outcomes.
Among girls, reallocating time to sleep was associated with negative predicted changes, and increasing MVPA or LPA was associated with positive differences in DC scores. For boys, reallocating time spent to MVPA was associated with positive predicted changes, whereas, increasing time in LPA was associated with negative differences in DC scores. Overall, MVPA had the greatest influence on motor competence outcomes in both boys and girls across school type. The largest positive and negative predicted differences in motor competence outcomes occurred, when MVPA replaced LPA or sleep and when LPA or sleep replaced MVPA, respectively. Again, consistent with previous systematic reviews showing various associations between PA and motor competence in boys and girls(2, 7), these findings further emphasise the key role of MVPA for both sexes’ motor competence. Notably, no other compositional analysis study(10–13) has investigated sex-stratified associations between activity composition and motor competence outcomes. Thus, we provide new evidence for the contention that time spent in MVPA (relative to other activities) is positively associated with motor competence outcomes irrespective of sex.
Using a hybrid-based assessment(1, 6), our findings represent a holistic view on the association between activity behaviours and motor competence(1). The largest predicted increases in overall, process, and time scores were observed when MVPA replaced LPA or sleep, whilst the largest predicted decreases occurred when LPA replaced MVPA. Further, the largest predicted increases in product score were observed when LPA replaced MVPA, and greatest decreases were when sleep or LPA replaced MVPA. These results contrast with the recent systematic review evidence(3), as well as a non-compositional study using both process- and product-based assessments of motor competence no associations between MVPA and motor competence(3, 26). Further, previous research utilising compositional data analysis has only considered motor competence outcomes using a process-based approach(10–13), and whilst positive changes in motor competence were found(10–13), the current study provides further evidence that associations exist between MVPA (relative to other activity behaviours) and both process- and product-based motor competence outcomes. Thus, irrespective of a process- or product-based assessment approach used to assess motor competence, our findings suggest that enabling engagement in MVPA is beneficial for motor competence in all children and adolescents.
Interestingly, the predicted differences in motor competence outcomes were greatest when MVPA was replaced by sleep or LPA, rather than when MVPA replaced these behaviours. These asymmetrical associated differences in physical outcomes involving MVPA have previously been observed in youth studies considering adiposity and fitness(27). Furthermore, some studies have reported negative associations between ST and motor competence(7, 28). We found that ST, relative to the other activity behaviours was not significantly associated with any of the motor competence outcomes. However, in Table 2, a negative association was present for the full sample, but inconsistent in the sub-group analyses, therefore, the lack of consistent significant association may be a combination of statistical artefact (i.e., small sample sizes) and potential misclassification of LPA as ST. Nonetheless, further studies on the potential negative effects of ST on the development of motor competence are warranted.
In line with the recent review evidence reporting a lack of association between PA and motor competence(3), it is noteworthy, that there were no significant associations observed between the activity compositions and numerous DC scores (Table 2). These non-significant associations between activity behaviours and outcomes requires further investigation, but it may mean that other influencing factors better predict motor competence outcomes(3, 4, 8). Therefore, children/adolescents may benefit other interventions such as appropriately challenging opportunities, instruction and feedback during activities, to complement increases in MVPA, as opposed to just time reallocated to MVPA(2–5, 8).
Strengths of this study included wrist-worn device-based assessment of 24-hour activity behaviours and use of compositional data analysis to examine how the full activity composition related to motor competence outcomes. Moreover, this is the first compositional analysis study to investigate motor competence outcomes, measured using a hybrid-based assessment that evaluates proficiency in fundamental, combined, and complex movement skills. However, the study is not without limitations. The cross-sectional design precludes any claims of causal inferences and directionality between the activity composition and motor competence outcomes. There is also evidence for a motor competence to PA association, thus there is a possibility of reverse causality or bi-directional associations(2, 3, 5). Furthermore, the authors acknowledge an increased type 2 error risk from conducting a large number of hypothesis tests (as a result of stratification by sex and school type). Nevertheless, the novel findings that MVPA, relative to other behaviours, was associated with various motor competence outcomes in both primary and secondary school participants, suggests that the association between MVPA and motor competence is still present during middle to late childhood and adolescence(2, 3, 5). We also had an imbalanced sample of primary and secondary school participants, who were relatively homogenous in terms of area-level socioeconomic status, which limits generalisability. Therefore, future studies should extend this work across the full spectrum of area-level socioeconomic status/neighbourhood deprivation. Finally, although the activity behaviours were defined using validated wrist-worn acceleration cut-points for LPA and MVPA, these reflect absolute intensity rather than relative intensity for each participant and therefore, may have resulted in some misclassification of activity behaviours.