Differential effects of acute physical activity on executive function in preschoolers with high and low habitual physical activity levels

Highlights

• The habitual physical activity was assessed using accelerometers.

• One bout of 20-min moderate-to-vigorous physical activity (MVPA) facilitated preschoolers' performance of cognitive flexibility.

• Preschoolers with higher habitual PA levels benefit more from one bout of MVPA in inhibitory control.

• One bout of MVPA had no significant effect on working memory.

Abstract

Objectives

To investigate the effect of one bout of moderate-to vigorous-intensity physical activity (MVPA) on executive function in preschoolers, and the moderating effect of children's habitual physical activity (PA) levels.

Method

Based on accelerometer data from three weekdays and one weekend, 63 children aged 3–5 years were divided into tertiles. Children in the upper (n = 21) and lower (n = 20) tertiles participated in an intervention experiment. Using a within-subject design, 41 children participated in 25 min of PA (20 min of MVPA) and a sedentary control condition in random order on 2 separate days. The day–night Stroop, Corsi block, and dimensional change card sort (DCCS) tasks were administered individually in counterbalanced order after completion of each intervention activity. Repeated-measures analysis of variance was used to examine pre–post-test changes in task performance in the high and low PA groups.

Results

Flexibility performance on the DCCS task was temporarily enhanced by one bout of PA in preschoolers [F (1, 39) = 5.95, p = 0.02, η² = 0.13]. An interaction effect was observed between the habitual PA level and acute PA on cognitive control [F (1, 39) = 5.47, p = 0.03, η² = 0.12]. The acute PA intervention improved day–night Stroop reaction times in children with high (F = 9.15, p < 0.01), but not low, habitual PA levels (F = 0.10, p = 0.75).

Conclusion

Acute MVPA temporarily improves the cognitive performance of preschoolers, with a greater benefit for children with higher habitual PA levels.

Introduction

Early childhood is thought of as a critical period for the development of cognitive functions and formation of life-long physical activity (PA) habits (Jones, Hinkley, Okely, & Salmon, 2013). Extant studies have used objective monitoring of PA to reveal relationships to cognitive performance in children (Sibley & Etnier, 2003) and in particular early childhood (Carson et al., 2016). PA has been found to be beneficial for working memory (López-Vicente et al., 2017), attention capacity (Vanhelst et al., 2016), executive function (Chang, Tsai, Chen, & Hung, 2013; Diamond & Lee, 2011), academic performance (Dwyer, Sallis, Blizzard, Lazarus, & Dean, 2001), brain structure (Gunnell et al., 2018) and brain functions (Chaddock et al., 2013) in children and adolescents.

Accumulating evidence suggests that a single bout of PA temporarily facilitates executive functions (Best, 2010; Chen, Yan, Yin, Pan, & Chang, 2014), which are goal-oriented control functions of the prefrontal cortex, consist of inhibitory control, working memory and cognitive flexibility (Diamond, 2013).A recent meta-analysis showed that a single PA bout has a small to moderate positive effect on inhibition, but no effect on working memory or cognitive flexibility, in preadolescent children (de Greeff, Bosker, Oosterlaan, Visscher, & Hartman, 2018). Similar results were obtained in a meta-analysis focused on the effects of acute PA on different domains of executive function; moderate effects on inhibition/interference control in children (d = 0.57) and adolescents (d = 0.52) and a small effect on planning in children (d = 0.16) were found (Verburgh, Königs, Scherder, & Oosterlaan, 2013). However, none of these studies included preschoolers younger than 6 years of age. The findings of one study suggest that acute moderate-to vigorous-intensity PA has an impact on sustained attention in preschoolers (Palmer, Miller, & Robinson, 2013). However, little evidence exists on whether single PA bouts affect preschoolers’ executive function (Tandon et al., 2018).

Thus, although numerous studies have suggested positive relationships between acute PA and cognitive performance, the findings are inconsistent (Donnelly et al., 2016). This association is moderated by several related factors. Drollette et al. (2014) revealed that single PA bouts had different effects on children with various inhibitory control capacities; specifically, children with lower capacities benefitted more. Furthermore, an interaction may exist between acute PA and physical fitness. Notably, compared with unfit adolescents, a fit group showed better cognitive task performance at baseline and benefitted more from short-term aerobic exercise (Chang, Chu, Wang, Song, & Wei, 2015; Hogan et al., 2013).

The main goal of this study was to investigate the effect of acute moderate-to vigorous-intensity physical activity (MVPA) on executive functions in preschoolers. To further understand the underlying association between acute PA and executive function, we included interindividual differences in habitual PA levels as a potential moderator. According to existing evidence, we expected that acute PA would temporarily enhance preschoolers’ executive functions, with a larger effect on inhibitory control, and that preschoolers with various habitual PA levels would benefit differently from single PA bouts.