Associations of Class-Time Sitting, Stepping and Sit-to-Stand Transitions with Cognitive Functions and Brain Activity in Children

Accelerometer-measured sedentary volume and bouts during the segmented school day among Chinese school students

Background

This study examined sedentary volume and bouts of Chinese primary and middle school students during different segments of a school day and determined whether gender and school level are associated with their sedentary volume and bouts.

Methods

A total of 472 students participated in this study. Accelerometers were used to measure the sedentary volume and sedentary bouts of different durations (i.e., 1-4 min, 5-9 min and ≥10 min) during all segments.

Results

The participants spent the majority of their time in sitting (61.7%) and sitting bouts of ≥10 min (37.3%). They spent higher percentages of time in sitting during regular classes (76.7%) and out-of-school time (54.5%), and lower during physical education (PE) classes (32.2%), lunch break (35.4%) and recess (38.0%). The highest proportions of time were in sedentary bouts of ≥10 min during regular classes (50.2%), out-of-school time (28.0%) and lunch break (18.8%), while the greatest percentages occurred in sitting bouts of 1-4 min during PE class (16.4%) and recess (18.6%). Girls and middle school students had higher percentages of sedentary volume than boys and primary school students during most segments. They spent greater proportions of time in sitting bouts of ≥10 min during regular classes, lunch break, and out-of-school time, and higher proportions in sedentary bouts of 1-4 min than boys and primary students during PE classes.

Conclusion

Regular class and out-of-school time were identified as key segments for reducing sedentary volume and breaking up prolonged sitting. Interventions on interrupting prolonged sitting during lunch break should also be explored. Girls and middle school students should receive more attention in future interventions.

Associations of habitual sedentary time with executive functioning and short-term memory in 7th and 8th grade adolescents

BACKGROUND

While there is increasing evidence for negative physical health consequences of high volumes of sedentary time and prolonged sedentary time in adolescents, the association with cognition is less clear. This study investigated the association of volumes of habitual sedentary time and prolonged sedentary time with executive functions and short-term memory in adolescents.

METHODS

This study has a cross-sectional observational study design. Volumes of sedentary time and prolonged sedentary time (accumulated sedentary time spent in bouts of  ≥ 30 min) were measured using the Axivity AX3 accelerometer. Six cognitive functions (spatial and verbal short-term memory; and working memory, visuospatial working memory, response inhibition and planning as executive functions) were measured using six validated cognitive assessments. Data were analysed using generalised linear models.

RESULTS

Data of 119 adolescents were analysed (49% boys, 13.4 ± 0.6 year). No evidence for an association of volumes of sedentary time and prolonged sedentary time with spatial and verbal short-term memory, working memory, and visuospatial working memory was found. Volumes of sedentary time and prolonged sedentary time were significantly related to planning. One hour more sedentary time or prolonged sedentary time per day was associated with respectively on average 17.7% (95% C.I.: 3.5-29.7%) and 12.1% (95% C.I.: 3.9-19.6%) lower scores on the planning task.

CONCLUSIONS

No evidence was found for an association of volumes of habitual sedentary time and prolonged sedentary time with short-term memory and executive functions, except for planning. Furthermore, the context of sedentary activities could be an important confounder in the association of sedentary time and prolonged sedentary time with cognition among adolescents. Future research should therefore collect data on the context of sedentary activities.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov in January 2020 (NCT04327414; released on March 11, 2020).

Primary school learners' movement during class time: perceptions of educators in the Western Cape, South Africa

BACKGROUND

Over the last decade, the efficacy of in-classroom movement to reduce sedentary behaviour has been mainly conducted in high-income, developed countries. To date, there have been no published reports on the perceptions of principals and teachers regarding learners' movement during class time to inform the implementation of classroom-based movement strategies to reduce sedentariness in South Africa.

METHODS

A sample of primary school principals and grades 5 and 6 teachers from a range of socio-economic categories participated in this exploratory, descriptive qualitative study in the metro central district of the Western Cape Education Department in South Africa. Transcripts of individual depth interviews (IDIs) with principals and focus group discussions (FGDs) with teachers were coded using Atlast ti 9* software for qualitative analysis.

RESULTS

Thirteen principals (13 IDIs) and 24 teachers (6 FGDs) participated in the study. Two main factors influencing in-classroom movement, namely teacher-related and structural factors, were identified. The teacher-related factors pertained to their classroom management practice, knowledge and beliefs about sitting, and management style influenced their role in delivering the curriculum and creating a classroom environment conducive for learning. Classroom factors pertained to classroom size, the number of learners in the class and the ergonomic utility of traditional classroom desks. Institutional expectations and acceptance of learners' behaviour, and teachers' practice were also notable contributing factors that influenced learners' movement during class time.

CONCLUSION

Emerging evidence about the efficacy of in-classroom movement on sedentary behaviour and learning outcomes challenges traditional teacher practice that sitting is essential for the delivery of the curriculum and for creating an optimal learning environment. Teacher training about the behaviour control utility of in-classroom movement, and school management and policy supportive of in-classroom movement may encourage fidelity to in-classroom movement strategies.

Breaking Sitting Time with Physical Activity Increases Energy Expenditure but Does Not Alter Postprandial Metabolism in Girls

PURPOSE

Young people spend a substantial proportion of their time at school sedentary; therefore, this setting represents an important target for interventions aimed at displacing sedentary time with physical activity. This study aimed to examine the postprandial metabolic effects of breaking sedentary time by accumulating walking and repeated bouts of nonambulatory standing during simulated school days in inactive adolescent girls.

METHODS

Seventeen girls (mean ± SD = 12.8 ± 0.4 yr) completed two 3-d experimental conditions. On days 1 and 2 of the standing + walking (STD-WLK) experimental trial, participants interrupted sedentary time by completing 4 × 10 min bouts of self-paced walking and accumulated 18 × 5 min standing bouts during each simulated school day. On day 3 of STD-WLK, participants attended school as normal with no additional physical activity or standing prescribed. On all 3 d of the control condition (CON), participants attended school as normal with no physical activity intervention. On days 2 and 3 of both STD-WLK and CON, a baseline capillary blood sample was provided to determine fasting [TAG] and [glucose]. Participants then consumed a standardized breakfast (0 h) and lunch (4.7 h), and blood samples were provided postprandially at 2.7, 5.3, and 7.3 h for [TAG] and [glucose].

RESULTS

Energy expenditure was 28% (95% confidence interval = 8% to 52%) higher during school hours on day 1 and day 2 during STD-WLK compared with CON (2171 vs 1693 kJ; effect size = 0.89, P = 0.008). However, no reduction of fasting or postprandial [TAG] or [glucose] was observed on day 2 or day 3 ( P ≥ 0.245).

CONCLUSIONS

Two consecutive days of breaking prolonged sitting with self-paced walking and intermittent standing had no meaningful effect on postprandial metabolism in adolescent girls.

Effects of using standing desks for 45 minutes on the stress and executive function of elementary school students

Studies have presented data regarding the effects of short-term (weeks) and long-term (one year) use of standing desks in classrooms on children’s health, cognition, and musculoskeletal symptoms. However, no previous study has examined such effects in an extremely short-term period such as one classroom lesson. This study aimed to examine the effects of using standing desks for 45 minutes on elementary school students’ stress and executive function. For this experiment, 56 students were recruited from public elementary schools in Setagayaku, Tokyo, Japan. There were three conditions involving the use of standing desks (standing, sitting, and mixed), and all students performed tasks for 45 minutes in each condition. Measurements of stress and executive function were performed before and after the students engaged with each condition. Stress levels did not differ between the sitting and standing conditions for the full 45 minutes. The number of correct answers in the Stroop test, an interference task, was higher in the standing and mixed conditions (switching between standing and sitting) than in the sitting condition (interaction: F_(1,37) = 3.340, p = 0.04, η² = 0.05). These results indicate that using standing desks for 45 minutes improved the ‘inhibition’ of executive function without excessively increasing stress levels.

Influence of Sit-Stand Tables in Classrooms on Children's Sedentary Behavior and Teacher's Acceptance and Feasibility: A Mixed-Methods Study

Children spend over 70% of their school day sitting, most of the time in the classroom. Even when meeting physical activity guidelines but sitting for long uninterrupted periods, children are at risk of poorer health outcomes. With an approach to create an active learning environment through the implementation of sit-stand tables, this exploratory mixed-methods study aims to evaluate a holistic concept for reducing sedentary time in schools by implementing sit-stand tables as well as to examine the feasibility and didactic usability in classroom settings. Children from eight German schools aged 7 to 10 in primary schools and 11 to 13 in secondary schools (n = 211), allocated into control and intervention groups, were included in the study, as well as teachers (n = 13). An accelerometer was used as a quantitative measure to assess sitting and standing times and sport motoric tests were taken. Qualitative interviews were performed with teachers regarding feasibility and acceptance of the sit-stand tables. Independent t-test analysis adjusted for age, sex and school type found that sitting times of children in the intervention group could be reduced (by 30.54 min per school day of 6 h, p < 0.001) within all school and age levels. Overall, implementing sit-stand tables in classrooms serves as a feasible and effective opportunity to reduce sedentary behaviour and create an active learning environment.

The Acute Effects of Standing on Executive Functioning in Vocational Education and Training Students: The Phit2Learn Study

Research suggests that sedentary behavior (SB) is negatively associated with cognitive outcomes. Interrupting prolonged sitting has been shown to improve cognitive functions, including executive functioning (EF), which is important for academic performance. No research has been conducted on the effect of standing on EF in VET students, who make up a large proportion of the adolescent population and who are known to sit more than other students of this age. In this study, we investigated the acute effects of reducing SB by short time standing on EF in vocational education and training (VET) students. In a randomized crossover study, 165 VET students were first taught for 15 min in seated position. After this, they performed while seated the Letter Memory Test for updating, and the Color Shape Test for shifting and inhibition. Students were randomly assigned to a sitting or standing condition. All students were taught again for 15 min and then took the same tests in the condition they were allocated to, respectively, standing or seated. After 1 week, the test procedure was repeated, in which students switched conditions. Mixed model analyses showed no significant effect of sitting or standing on updating, shifting, or inhibition. Also, no significant differences were found for the order of condition on updating, shifting, or inhibition. Our results suggest that 40 min of standing does not significantly influence EF among VET students.

Promoting physical activity and health in Hong Kong primary school children through a blended physical literacy intervention: protocol and baseline characteristics of the "Stand+Move" randomized controlled trial

Background

Children predominantly remain sedentary in a traditional classroom. This study aimed to demonstrate the design and baseline characteristics of a three-armed intervention program that targeted enhancements in children’s physical literacy (PL), physical activity (PA), sleep, and executive functions by constructing an active classroom environment in primary schools. The blended approach involved organized PA participation during recess combined with changes to the classroom environment in response to the emphasis on nurturing children’s PL in Hong Kong.

Methods

This blended “Stand + Move” intervention adopted a randomized controlled trial design to investigate its effectiveness in improving health-related aspects. Three groups were compared: (1) PA recess intervention, (2) blended (sit-stand desks and PA recess) experimental, and (3) control groups. In this 13-week intervention (from March to September 2019), 76 students (59.2% girls) were recruited and randomly assigned to the three groups. The primary outcomes were children’s PL and PA. The secondary outcomes were children’s sleep and executive functions.

Results

Baseline data were evaluated. The mean age was 9.6 years [standard deviation = 0.61, range 9.0–12.0]. There were no significant differences between trial arms at baseline concerning any of the outcomes (all P = 0.06–0.89). Overall, 22.4% met the recommended PA guidelines, 36.8% met the sleep guidelines, and 10.5% met both guidelines. Three aspects of executive functions were evaluated: inhibition, executive control, and planning. Over half of the participants reported satisfaction with their perceived sleep quality.

Conclusions

The designed intervention is regarded as an innovative strategy that incorporates sit-stand desks and PA breaks to reconstruct children’s traditional classroom environment. The baseline results suggest that intervention was satisfactory in reducing students’ sitting time and increasing their PA engagement. We demonstrated the benefits of this intervention on children’s PL, various sleep patterns, and executive functions. As expected, the designed intervention changes made to the classroom improved children’s health behaviors, as well as the support from stakeholders at schools and the children’s families. Our results also provided the desired evidence for policy reforms in teaching and learning strategies.

Trial registration

ChiCTR ChiCTR2000035038. Registered on July 29, 2020—retrospectively registered

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05925-y.

Breaking up classroom sitting time with cognitively engaging physical activity: Behavioural and brain responses

INTRODUCTION

Classroom-based active breaks are a feasible and effective way to reduce and break up sitting time, and to potentially benefit physical health in school children. However, the effect of active breaks on children's cognitive functions and brain activity remains unclear.

OBJECTIVE

We investigated the impact of an active break intervention on typically developing children's cognitive functions and brain activity, sitting/standing/stepping, on-task behaviour, and enjoyment.

METHODS

Up to 141 children, aged between 6 and 8 years (46% girls), were included, although about half of them completed two of the assessments (n = 77, working memory; n = 67, dorsolateral prefrontal cortex haemodynamic response). Classrooms from two consenting schools were randomly allocated to a six-week simple or cognitively engaging active break intervention. Classrooms from another school acted as a control group. The main analyses used linear mixed models, clustered at the class level and adjusted for sex and age, to investigate the effects of the interventions on response inhibition, lapses of attention, working memory, event-related brain haemodynamic response (dorsolateral prefrontal cortex). The mediating effects of sitting/standing/stepping on cognition/brain activity were also explored. To test intervention fidelity, we investigated differences by group on the change values in children's sitting, standing, and moving patterns during class/school time using linear mixed models. Generalized linear mixed models clustered at the individual level were used to examine on-task behaviour data. For the intervention groups only, we also assessed children's perceived enjoyment, physical exertion and mental exertion related to the active breaks and compared the results using independent t-tests.

RESULTS

There was a significantly greater positive change in the proportion of deoxygenated haemoglobin in the left dorsolateral prefrontal cortex of children assigned to cognitively engaging active breaks compared to the control group (B = 1.53 × 10-07, 95% CI [0.17 × 10-07, 2.90 × 10-07]), which under the same cognitive performance is suggestive of improved neural efficiency. Mixed models showed no significant effects on response inhibition, lapses of attention, working memory. The mediation analysis revealed that the active breaks positively affected response inhibition via a change in sitting and standing time. The sitting, standing, and moving patterns and on-task behaviour were positively affected by the active breaks at end of trial, but not at mid-trial. Children in both intervention groups showed similarly high levels of enjoyment of active breaks.

CONCLUSION

Cognitively engaging active breaks may improve brain efficiency in the dorsolateral prefrontal cortex, the neural substrate of executive functions, as well as response inhibition, via effects partially mediated by the change in sitting/stepping time. Active breaks can effectively reduce sitting and increase standing/stepping and improve on-task behaviour, but the regular implementation of these activities might require time for teachers to become familiar with. Further research is needed to confirm what type of active break best facilitates cognition.

Age-Related Differential Effects of School-Based Sitting and Movement Meditation on Creativity and Spatial Cognition: A Pilot Study

Psychophysical well-being can be supported during development by the integration of extra-curricular activities in scholastic settings. These activities can be implemented in different forms, ranging from physical activities to sitting meditation practices. Considering that both such activities are thought to affect children’s psychophysical development, a movement-based meditation that combines the two approaches−in the form of a short daily activity−could represent a powerful tool to promote healthy physical and mental development. Consequently, the current pilot study aimed to examine the effect of short daily school-based sitting and movement meditation trainings on creativity and spatial cognition. Utilizing a crossover design, we evaluated their feasibility and efficacy at different ages among children (n = 50) in 5th to 8th grade. We observed that 5 weeks of daily training in sitting and movement meditation techniques improved children’s cognition differently. Specifically, younger children showed greater creativity and better spatial cognition following the movement-based meditation, while older children showed greater enhancement in these areas following sitting meditation training. This suggests that training can affect children’s cognition differently depending on their developmental stage. We discuss these results within the framework of embodied and grounded cognition theories. Information on feasibility and age-related effect sizes derived from the current study paves the way for future well-powered larger-scale efficacy studies on different forms of school-based interventions to cognitive development promotion.

Active School Breaks and Students' Attention: A Systematic Review with Meta-Analysis

School physical activity breaks are currently being proposed as a way to improve students’ learning. However, there is no clear evidence of the effects of active school breaks on academic-related cognitive outcomes. The present systematic review with meta-analysis scrutinized and synthesized the literature related to the effects of active breaks on students’ attention. On January 12th, 2021, PubMed, PsycINFO, Scopus, SPORTDiscus, and Web of Science were searched for published interventions with counterbalanced cross-over or parallel-groups designs with a control group, including school-based active breaks, objective attentional outcomes, and healthy students of any age. Studies’ results were qualitatively synthesized, and meta-analyses were performed if at least three study groups provided pre-post data for the same measure. Results showed some positive acute and chronic effects of active breaks on attentional outcomes (i.e., accuracy, concentration, inhibition, and sustained attention), especially on selective attention. However, most of the results were not significant. The small number of included studies and their heterogeneous design are the primary limitations of the present study. Although the results do not clearly point out the positive effects of active breaks, they do not compromise students’ attention. The key roles of intensity and the leader of the active break are discussed. INPLASY registration number: 202110054.

A Qualitative Study of the Feasibility and Acceptability of Implementing 'Sit-To-Stand' Desks in Vocational Education and Training

While it has been shown that interrupting a person’s sedentary behaviour has the potential to improve cognitive, physical and mental health, a large part of time that students spend in school is sedentary. As research has shown that approximately 80% of vocational education and training (VET) students have an unhealthy sedentary lifestyle, implementing “sit-to-stand” (StS) desks could interrupt sedentary behaviour and promote healthier behaviour. Therefore, the acceptability and feasibility of using such desks in the VET setting should be investigated. Using semi-structured focus group interviews analysed via deductive content analysis, the opinions of 33 students for the following topics were assessed: (1) usage of the standing option of the desks (2) reasons for standing in class (3) experienced effect of standing behind the desk, and (4) fostering future StS desks usage. Although VET students are aware of the potential benefits of using StS desks, they need to be actively stimulated and motivated by teachers to use them. In addition, time is needed to get into the habit of standing. Thus, for successful implementation of StS desks in the VET setting, all stakeholders (i.e., students, teachers, schoolboards) should be actively involved in stimulating the healthy behaviour of VET students.

Brain activity during a working memory task in different postures: an EEG study

While working is more comfortable in a supine position and healthier in a standing, most people work in a sitting. However, it is unclear whether there are differences in brain activity efficiency in different postures. Here, we, therefore, compared changes in brain activity across three different postures to determine the optimal posture for performing working memory tasks. Their effect on brain activity was examined using EEG signals together with the information of accuracy and reaction times during 2-back task in 24 subjects. Substantial differences in brain waves were observed at sitting and standing positions compared to the supine, especially in delta waves and frontal lobe, where is known to improve the modulation of brain activity efficiently. Brain efficiency was higher during standing and sitting than in a supine. These findings show that postural changes may affect the efficiency of brain activity during working memory tasks. Practitioner summary: Differences in brain efficiency between different postures during working memory tasks have not been explored. This study suggests that efficiency in several brain areas is higher during sitting and standing than in a supine position. This finding has important implications regarding workplace environments. Furthermore, this result would be useful to improve accomplishment and reduce negative effects of work posture. Abbreviations: EEG: electroencephalogram; PSQI: Pittsburgh sleep quality index; KSS: Karolinska sleepiness scale; FFT: fast fourier transform; ROI: region of interest; ANS: autonomic nervous system; Fp: prefrontal; AF: anterior frontal; frontal; Fz: midline frontal; temporal; central; Cz: midline central; P: parietal; Pz: midline parietal; O: occipital; Oz: midline occipital.

Motor Development Research: II. The First Two Decades of the 21st Century Shaping Our Future

In Part I of this series I, we looked back at the 20th century and re-examined the history of Motor Development research described in Clark & Whitall’s 1989 paper “What is Motor Development? The Lessons of History”. We now move to the 21st century, where the trajectories of developmental research have evolved in focus, branched in scope, and diverged into three new areas. These have progressed to be independent research areas, co-existing in time. We posit that the research focus on Dynamical Systems at the end of the 20th century has evolved into a Developmental Systems approach in the 21st century. Additionally, the focus on brain imaging and the neural basis of movement have resulted in a new approach, which we entitled Developmental Motor Neuroscience. Finally, as the world-wide obesity epidemic identified in the 1990s threatened to become a public health crisis, researchers in the field responded by examining the role of motor development in physical activity and health-related outcomes; we refer to this research area as the Developmental Health approach. The glue that holds these research areas together is their focus on movement behavior as it changes across the lifespan.

Uninterrupted Classroom Sitting is Associated with Increased Discomfort and Sleepiness Among College Students

Acute bouts of uninterrupted sitting has been associated with discomfort and fatigue in adult populations. However, little is known regarding the impact of uninterrupted sitting on such outcomes among college students. Understanding these relations would be useful for informing best practice and future interventions. The present study explored the relation between uninterrupted sitting and perceived levels of physical discomfort and sleepiness among college students in a real classroom setting. We recruited 54 undergraduate students enrolled in a single class at a Midwestern university. Participants remained seated throughout a 2.5 h lecture while completing the Stanford Sleepiness Scale (SSS) and General Comfort Scale (GCS) every 15 min. Linear mixed effect model analyses were used to determine the relations between the independent and dependent variables and the duration at which students reported significant impairments in discomfort and/or sleepiness. Classroom sitting time was associated with increases in discomfort (r = 0.28, p < 0.01) and sleepiness (r = 0.30, p < 0.01). Students reported significant impairments in discomfort and sleepiness after 75 and 15 min, respectively. These findings support further research into the acceptability, feasibility and efficacy of interventions designed to interrupt classroom sitting on discomfort, sleepiness and measures of academic performance.