Run fast and sit still: Connections among aerobic fitness, physical activity, and sedentary time with executive function during pre-kindergarten

Highlights

• Moderate to vigorous physical activity is positively related to executive function for children with low aerobic fitness.

• For children with high aerobic fitness, moderate to vigorous physical activity is unrelated to executive function.

• Sedentary to light activity is positively related to fall to spring change in executive function scores for children with high aerobic fitness.

• Sedentary to light activity is unrelated to change in fall to spring executive function scores for children with low aerobic fitness.

Abstract

This study examined direct and moderated connections among aerobic fitness, objectively measured sedentary to light physical activity (SLPA), moderate to vigorous physical activity (MVPA), and executive function (EF) during pre-kindergarten. Children (n = 81) between the ages of 3 and 5 were recruited from 17 classrooms from 7 center-based pre-kindergartens. In the fall (T1) and spring (T2), children were assessed using the Head-Toes-Knees-Shoulders (HTKS) and Day-Night Stroop, and physical activity (PA) was measured at T1 over 4 days during waking hours within each pre-kindergarten. At T1, aerobic fitness significantly moderated the connection between MVPA and the Day-Night Stroop. For children with low aerobic fitness, time in MVPA predicted higher Day-Night scores, with MVPA unrelated to Day-Night scores for children with high aerobic fitness. Results also showed a similar trend level interaction for the HTKS at T1 between aerobic fitness and MVPA. Between T1 and T2, aerobic fitness also significantly moderated the connection between SLPA with change in HTKS scores. For children with high aerobic fitness, time in SLPA predicted positive change in HTKS scores, with SLPA unrelated to change in HTKS scores for children with low aerobic fitness. Findings are discussed in the context of considering not only how PA and aerobic fitness relate to early cognitive development, but also how sedentary to light activity and aerobic fitness could promote and develop EF.

Introduction

The pre-kindergarten years are a crucial time in the development of both educational and health related skills linked to positive developmental trajectories. Executive function (EF), which includes cognitive processes of working memory, inhibitory control, and cognitive flexibility, shows a high rate of growth during these early developmental years (Carlson, 2005). Overwhelming evidence supports the cognitive and educational benefits of strong EF, with EF in pre-kindergarten linked to the development of mathematical competency and reading proficiency in grade school and beyond (Becker, Miao, Duncan & McClelland, 2014; Best, Miller & Naglieri, 2011). Along with the positive educational trajectory related to better EF, children with strong EF also exhibit a heightened ability to process abstract and scientific information (Benedek, Jauk, Sommer, Arendasy & Neubauer, 2014; Zaitchik, Iqbal & Carey, 2014).

It is during these early years where the brain is also primed for motor learning and EF can be tied to both physical activity (PA) and aerobic fitness (an index of physical health) (D. R. Becker, McClelland, Loprinzi & Trost, 2014; Oberer, Gashaj & Roebers, 2018). As an increasing number of children under age 5 are spending some part of their day in childcare settings, research has begun to focus on the amount of PA children are achieving within these early care settings (Andersen et al., 2017). Although several advisory commissions suggest that children between 3 and 5 should obtain 3 hours of PA per day with 1 hour of PA at moderate to vigorous intensity (Cliff et al., 2017; Okely et al., 2017; Tremblay et al., 2016), recent estimates suggest the level of moderate to vigorous physical activity (MVPA) varies widely in pre-kindergarten aged children (12 minutes to 5 h, Ravagnani et al., 2017), with children spending as much as 63% of their waking time in sedentary activities while attending childcare (Pereira, Cliff, Sousa-Sá, Zhang & Santos, 2019). Most children are also not meeting the recommended level of PA (Pate et al., 2015), and it is not clear how high or low levels of PA during the pre-kindergarten day relate to a child's cognitive and physical health.

Evidence suggests that children who spend more time in MVPA during outdoor play perform better on EF tasks (D. R. Becker et al., 2014), but sedentary to light activity is also linked to better cognitive function when assessed outside the childcare setting (Aggio, Smith, Fisher & Hamer, 2016). The typical pre-kindergarten day includes indoor and outdoor activities and the opportunity to move at low and high levels of PA, which highlights a need to understand how different levels of PA relate to EF within the early care setting.

As evidence also suggests that pre-kindergarten children who spend more time in MVPA show better aerobic fitness (Leppänen et al., 2017), with aerobic fitness linked to higher EF (Niederer et al., 2011; Oberer et al., 2018), it is also possible that a child's level of fitness could moderate the connection between low and high PA with EF during the pre-kindergarten year. To better understand connections among variability in high and low levels of PA, aerobic fitness, and EF during pre-kindergarten, it is the goal of this study to investigate if different levels of PA (sedentary, light, moderate, and vigorous) assessed during fall of the pre-kindergarten year predict fall and spring EF. This study will also examine if fall aerobic fitness predicts EF in the fall and spring, and if the relationship between EF with low and high levels of PA vary at different levels of fitness.