Effects of 24-h Movement Behaviours on Emotional and Behavioural Problems in Chinese Preschoolers Using Compositional...

The associations between 24-h movement behaviours (24 h MBs) and emotional and behavioural problems (EBPs) in early years are not well understood. This study examined these associations in a nationally representative sample of Chinese preschoolers.

As part of the Chinese cohort of the SUNRISE International Study of Movement Behaviors in the Early Years main study, this research recruited 1316 children aged 3-4 years through multistage stratified cluster sampling in urban and rural areas across seven major administrative regions in China. Moderate- to vigorous-intensity physical activity (MVPA), light-intensity physical activity (LPA) and sedentary behaviour (SED) were measured using 24-h accelerometry over five consecutive days. Sleep duration was parent-reported. EBPs were evaluated using the parent-rated Strengths and Difficulties Questionnaire (SDQ), which assesses total difficulties, internalising problems, externalising problems and prosocial behaviour. Compositional multiple linear regression was employed to analyse the relationships between 24 h MBs and EBPs. Compositional isotemporal substitution was also utilised to predict changes in EBPs due to reallocating time among 24 h MBs.

Isotemporal substitution analyses revealed that replacing as little as 1 min of MVPA, LPA or SED with sleep was associated with significant reductions in total difficulties (β_MVPA = -0.01, 95%CI -0.02 to -0.01; β_LPA = -0.01, 95%CI -0.01 to -0.001; β_SED = -0.01, 95%CI -0.02 to -0.01) and externalising problems (β_MVPA = -0.01, 95%CI -0.01 to -0.002; β_LPA = -0.003, 95%CI -0.01 to -0.0003; β_SED = -0.005, 95%CI -0.01 to -0.002). Similarly, reallocating MVPA or SED with sleep was associated with significantly reduced internalising problems (β_MVPA = -0.01, 95%CI -0.01 to -0.002; β_SED = -0.01, 95%CI -0.01 to -0.004). A significant predicted improvement in prosocial behaviour was observed only when time was reallocated from SED to sleep (β = 0.002, 95%CI 0.0002 to 0.004). Furthermore, transferring time from MVPA or SED to LPA was linked to a decrease in internalising problems (β_MVPA = -0.004, 95%CI -0.01 to -0.0002; β_SED = -0.004, 95%CI -0.01 to -0.002) and conduct problems (β_MVPA = -0.002, 95%CI -0.004 to -0.0003; β_SED = -0.01, 95%CI -0.002 to -0.0002).

Increasing LPA by reducing MVPA or SED was significantly associated with improvements in internalising and conduct problems, whereas increasing sleep to decrease MVPA or SED-even by small amounts-was consistently associated with improvements in EBPs across all SDQ subscales. However, increasing LPA at the expense of sleep exacerbates total difficulties and externalising problems. Promoting diverse LPA opportunities alongside sufficient sleep, while maintaining a balance between them, is essential for supporting preschoolers' emotional and behavioural development.