Development of sedentary behavior across childhood and adolescence: longitudinal analysis of the Gateshead Millennium Study

Hemodynamics of short-duration light-intensity physical exercise in the prefrontal cortex of children: a functional near-infrared spectroscopy study

Identifying the types of exercise that enhance cerebral blood flow is crucial for developing exercise programs that enhance cognitive function. Nevertheless, few studies have explored the amount of light-intensity, short-duration exercises that individuals can easily perform on cerebral blood flow, particularly in children. We examined the effects of these exercises on the hemodynamics of the prefrontal cortex (PFC) using functional near-infrared spectroscopy. Participants comprised 41 children (aged 12.1 ± 1.5 years, 37% female) who engaged in seven light-intensity exercises, with each movement performed in two patterns lasting 10 or 20 s. Changes in oxygenated hemoglobin (oxy-Hb) levels at rest and during exercise were compared using analysis of covariance, with sex and age as covariates. Significant increases in oxy-Hb were observed in multiple regions of the PFC during all forms of exercise (including dynamic and twist stretching [66.6%, 8/12 regions, η2 = 0.07-0.27], hand and finger movements [75.0%, 9/12 regions, η2 = 0.07-0.16], and balance exercises (100.0%, 6/6 regions, η2 = 0.13-0.25]), except for static stretching with monotonic movements. This study implies that short-duration, light-intensity exercises, provided that they entail a certain degree of cognitive and/or physical demands, can activate the PFC and increase blood flow.

Resistance training effects on pubertal children with a risk of developing pediatric dynapenia

PURPOSE

Many modern-day children are at risk of pediatric dynapenia (muscle weakness). We examined the effects of a 12-week resistance training (RT) program on neuromuscular function and body composition parameters in pubertal children with a risk of dynapenia.

METHODS

Twelve children (13.4 ± 0.9 y) with dynapenia performed a progressive RT program consisting of knee extension and flexion, bench press, abdominal crunch, back extension, lateral pull-down, elbow flexion, and upright row (1-2 sets of 10-15 repetitions/exercise) twice/week for 12 weeks. Outcome measures included one-repetition maximum (1-RM) strength, maximal voluntary isometric contraction (MVIC) torque, rate of torque development (RTD), electromyographic (EMG) activity, muscle thickness (MT), muscle quality (MQ) assessed by echo intensity (MQEI) of the knee extensors and specific tension of MVIC torque to thigh fat-free mass (MQST), and total and regional body and bone composition assessed by dual-energy X-ray absorptiometry. Changes in the measures before and after the 12-week RT and associations among the measures were analyzed by linear mixed models.

RESULTS

Significant (p < 0.05) increases in 1-RM (63.9 ± 4.5%), MVIC torque (16.3 ± 17.8%), MT (18.8 ± 5.5%) and MQ (MQEI: -25.9 ± 15.2%; MQST: 15.1 ± 18.8%;) were evident from pre- to post-training. Total fat-free mass (FFM) increased by 2.3 ± 3.2% from baseline (p = 0.01), but no changes (p > 0.05) in the other measures were observed. Significant (p < 0.05) associations between the changes in 1-RM and/or MVIC torque and the changes in quadriceps MT, MQEI, MQST and total body FFM were evident.

CONCLUSIONS

The 12-week RT was effective for improving neuromuscular and body composition parameters, and thereby reversed the risk of pediatric dynapenia.

Lifestyle Clusters of Diet Quality, Sleep, and Screen Time and Associations with Weight Status in Children from Madrid City: ENPIMAD Study

BACKGROUND

Childhood overweight and obesity is a global concern and has increased in Spain over the last decades. Combinations of lifestyle behaviors (i.e., diet, sleep, and sedentarism) are highly related to weight status. Therefore, this study aimed to identify lifestyle patterns among children from Madrid City, and analyze associations with the prevalence of overweight, obesity, and abdominal obesity, considering socio-economic factors.

METHODS

A cross-sectional analysis was conducted on 4545 children from the ENPIMAD study with data on diet, sleep, anthropometric, and socio-economic variables. K-means cluster analysis was used to identify lifestyle clusters, and logistic regressions were used to examine the associations between socio-economic indicators and cluster membership, and between clusters and weight status.

RESULTS

Findings show three lifestyle clusters (healthy, mixed, and unhealthy), with boys and older children more represented in the unhealthy cluster. Food insecurity and low socio-economic status were associated with unhealthier clusters in boys and girls. Children in unhealthier clusters were more likely to have obesity and abdominal obesity. However, these associations disappeared in girls after controlling for food insecurity.

CONCLUSION

These results provide insight into the combination of behaviors and socio-economic factors associated with childhood obesity that may aid in the design of future interventions.

Movement behaviour typologies and their associations with adiposity indicators in children and adolescents: a latent profile analysis of 24-h compositional data

OBJECTIVES

Growing evidence supports the important role of 24-hour movement behaviours (MB) in preventing childhood obesity. However, research to understand the heterogeneity and variability of MB among individuals and what kind of typologies of individuals are at risk of developing obesity is lacking. To bridge this gap, this study identified typologies of 24-hour MB in children and adolescents and investigated their associations with adiposity indicators.

METHODS

In this cross-sectional study, 374 children and 317 adolescents from the Czech Republic wore wrist-worn accelerometers for seven consecutive days. Time spent in moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), sedentary behaviour (SB), and sleep was quantified using raw accelerometery data. Adiposity indicators included body mass index (BMI) z-score, fat mass percentage (FM%), fat mass index (FMI), and visceral adipose tissue (VAT). Bias-adjusted latent profile analysis was used on the 24-hour MB data to identify MB typologies and their associations with adiposity indicators. The models were adjusted for potential confounders. The identified typologies were labelled to reflect the behavioural profiles of bees to aid interpretability for the general public.

RESULTS

Two typologies were identified in children: highly active Workers characterised by high levels of MVPA and LPA, and inactive Queens characterised by low levels of MVPA and LPA, high levels of SB and longer sleep duration compared to Workers. In adolescents, an additional typology labelled as Drones was characterised by median levels of MVPA, LPA, SB and longest sleep duration. After controlling for covariates, we found that children labelled as Queens were associated with 1.38 times higher FM%, 1.43 times higher FMI, and 1.67 times higher VAT than Workers. In adolescents, Drones had 1.14 times higher FM% and Queens had 1.36 higher VAT in comparison with Workers, respectively.

CONCLUSION

Our study highlights the importance of promoting active lifestyles in children and adolescents to potentially reduce adiposity. These findings can provide insights for interventions aimed at promoting healthy MB and preventing childhood obesity.

Tracking of MVPA across childhood and adolescence

OBJECTIVES

Tracking of physical activity from childhood onwards is an important public health issue, but evidence on tracking is limited. This study quantified the tracking of Moderate-Vigorous Physical Activity (MVPA) across childhood and adolescence in a recent cohort from England.

DESIGN

Longitudinal, with a socio-economically representative sample from North-East England, over an 8-year period.

METHODS

Measures of time spent in MVPA, with an Actigraph GT1M accelerometer, were made at age 7-8y (n = 622, T1), age 9-10y (n = 585, T2), age 12-13y (n = 525, T3) and age 14-16y (n = 361, T4). Tracking of MVPA was assessed using rank order correlations between time spent in MVPA T1-T2, T1-T3, and T1-T4, and by using Cohen's kappa to examine tracking of meeting the MVPA guideline (mean of 60 min/d). We examined whether tracking varied by sex, socio-economic status (SES), initial MVPA, or initial body fatness.

RESULTS

Rank order correlations were all statistically significant at p < 0.01 and moderate: 0.58 between T1 and T2; 0.42 between T1 and T3; 0.41 between T1 and T4. Cohen's kappas for meeting the global MVPA guideline were all significant, weakening from moderate to low over the 8 years. Tracking was stronger in higher SES compared to lower SES groups, and there was some evidence that it was stronger in girls than boys, but the other explanatory variables had little influence on tracking.

CONCLUSIONS

Tracking of MVPA from mid-childhood to mid-adolescence in this cohort was moderate. This study suggests there is a need to establish high MVPA by mid-childhood, and to mitigate the age-related reduction in MVPA which occurs from mid-childhood.

Prevalence of unhealthy behaviors and their associations with non-suicidal self-injury, suicidal ideation and suicide attempt among Chinese adolescents

BACKGROUND

Unhealthy lifestyle behaviors among adolescents have emerged as a significant public health concern worldwide, however, there is little investigation on the impact of unhealthy behaviors on non-suicidal self-injury (NSSI), suicidal ideation (SI) and suicide attempt (SA). This study aimed to investigate the prevalence of seven unhealthy behaviors as well as their associations with NSSI, SI and SA, and to explore whether the aforementioned associations differ across sex.

METHODS

A total of 74,152 adolescents were included in this study via a multi-stage, stratified cluster, random sampling method in 2021. Information about unhealthy behaviors (insufficient physical activity, current smoking, current drinking, excessive screen time, long homework time, insufficient sleep and unhealthy BMI), NSSI, SI, SA and other demographics was collected. Sampling weights were used to estimate the prevalence, and the weighted logistic regression models were performed. Stratified analyses by sex and sensitive analyses were conducted.

RESULTS

Overview, the weighted prevalence of adolescents had more than five unhealthy behaviors were 5.2%, with boys showing a higher prevalence than girls (6.5% vs.3.8%). Current smoking, current drinking, excessive screen use, long homework time, insufficient sleep, and unhealthy BMI were significantly associated with NSSI, SI and SA. Moreover, adolescents with high lifestyle risk scores were associated with an increased risk of NSSI (5-7 vs. 0: OR 6.38, 95% CI 5.24-7.77), SI (5-7 vs. 0: OR 7.67, 95% CI 6.35-9.25), and SA (5-7 vs. 0: OR 9.57, 95% CI 6.95-13.17). Significant sex differences were found in the associations of unhealthy behaviors with NSSI, SI and SA.

CONCLUSION

Unhealthy behaviors are quite common among Chinese adolescents. Adolescents with multiple unhealthy behaviors are associated with increased risks of NSSI, SI, and SA. The implementation of school and family-based interventions to promote healthy lifestyles is recommended as a preventive measure against self-injurious behavior and suicidality in adolescents.

Replacing screen time, with physical activity and sleep time: influence on cardiovascular indicators and inflammatory markers in Brazilian children

OBJECTIVE

To examine if the substitution of different screen time intervals with light physical activity (LPA), moderate to vigorous physical activity (MVPA) and sleep is associated with cardiovascular indicators and inflammatory markers in children.

METHODS

This is a cross-sectional study developed with 186 children aged between six and 11 years old from public schools in southern Brazil. CRF was measured with the 6-minute running and walking test, following the Brazil Sports Project procedures. The percentage of fat was evaluated through DXA. LPA and MVPA were measured using accelerometers. Sleep and screen time were assessed by questionnaires answered by parents. Leptin and C-reactive protein were measured by fasting blood collection. Systolic and diastolic blood pressure were determined through a digital sphygmomanometer. Isotemporal substitution models were used for statistical analysis.

RESULTS

Replacing 1 h of screen time with MVPA was associated with lower BMI, systolic and diastolic blood pressure, fat percentage, leptin, and C-reactive protein. When screen time was substituted for sleep time, lower waist circumference was observed. Regarding the substitution of 1 h of screen time with LPA, significant values were found only for leptin.

CONCLUSION

The replacement of screen time with physical activities of different intensities and sleep time was associated with benefits in cardiovascular indicators and inflammatory markers in childhood.

Associations between physical activity, sedentary time, and neurocognitive function during adolescence: Evidence from accelerometry and the flanker P300

Physical activity and sedentary behavior are two lifestyle factors related to overall health during adolescence. Public health efforts emphasize the importance of increasing physical activity to improve physical and mental health outcomes, including neurocognitive functioning. However, the unique effects of sedentary behavior on neurocognitive functioning remain unclear. This study aimed to investigate associations between daily moderate-to-vigorous physical activity (MVPA), sedentary time, and neurocognitive functioning during adolescence. Fifty-seven participants (37% female) between the ages of 13 and 17 years wore an accelerometer on their non-dominant wrist for approximately 1 week to quantify daily MVPA and sedentary time prior to completing a flanker task to elicit P300 amplitude at a laboratory visit. Results indicated that daily MVPA and sedentary time exhibited unique, significant associations with P300 amplitude in opposing directions: increased daily MVPA was correlated with larger P300 amplitudes, while increased daily sedentary time was linked to reduced P300 amplitudes. Notably, these associations remained significant even after adjusting for age, sex, and BMI-for-age percentile. These findings underscore the independent influence of daily MVPA and sedentary time on neurocognitive functioning during adolescence. Future research should explore whether modifying MVPA levels can improve neurocognitive outcomes-including the P300-during adolescence, and determine whether reducing sedentary time results in similar or differential effects.

The Effects of Using a Cycling Desk at School on Executive Function, Physical Fitness, and Body Composition in Primary School Children: Impact of Socioeconomic Status

CONTEXT

Physical inactivity and sedentary behaviors are associated with adverse health outcomes in both adults and children. The purpose of this study was to investigate the effects of a 9-week program using a Cycle Desk during school time in French primary school children from high or low socioeconomic status (SES) on body composition, physical fitness (PF), and executive function.

METHODS

Seventy-five (n = 75) children completed a test battery before and after 9 weeks of use of Cycle Desk to evaluate anthropometric characteristics, body composition, PF, and executive function.

RESULTS

Body mass index increased significantly (P = .0095), while body fat decreased after the use of Cycle Desks (P < .0001). Specifically, lean mass increased in the high-SES group while it decreased in the low-SES group (P < .0001). After 9 weeks, there was an improvement in motor skills (P < .0001), upper and lower limbs' strength (P < .0001), and executive function performance (P < .0001). More specifically, the low-SES group had a greater improvement in motor skills and maximal aerobic speed between T0 and T1, compared to the high-SES group (P = .001, P = .023, respectively). In contrast, the high-SES group had a greater improvement in executive function at 9 weeks of use of Cycle Desk compared with the low-SES group (P = .0084).

CONCLUSIONS

The promotion of low-intensity physical activity with the use of a Cycle Desk at school may help offset some adverse effects of excess sedentary behavior among children. Moreover, this strategy appears to be particularly effective in children from low-SES backgrounds. What's New: The use of a Cycle Desk during school time has no deleterious effects on PF as well as cognitive executive functions in primary children. Modifications are more beneficial in children from low SES.

Sedentary behavior patterns and the risk of non-communicable diseases and all-cause mortality: A systematic review and meta-analysis

BACKGROUND

The association between sedentary behavior and health-related outcomes has been well established, whereas it is inconclusive whether a sedentary behavior pattern is an additional risk factor for health-related outcomes independent of total sedentary time and physical activity.

OBJECTIVES

To determine sedentary behavior patterns and their association with risks of noncommunicable diseases and all-cause mortality and to assess whether this association is independent of total sedentary time and physical activity.

DESIGN

This was a systematic review and meta-analysis.

METHODS

Studies were obtained by searching the Web of Science Core Collection, PubMed/Medline, the Cochrane Library, Embase, CINAHL, and SPORTDiscus up to April 2023. All observational studies published in English or Chinese were included if they explored sedentary behavior patterns and their association with risks of abdominal obesity, metabolic syndrome, diabetes, cardiovascular disease, cancer, and all-cause mortality among individuals who had never experienced the outcome event before the baseline assessment. Data extraction using a standardized form and quality appraisal using two authoritative tools were then performed. All these steps were completed by two independent reviewers from December 2022 to May 2023. If data were sufficiently homogenous, meta-analyses were performed; otherwise, narrative syntheses were employed. Harvest plots were also used to visually represent the distribution of evidence.

RESULTS

Eighteen studies comprising 11 prospective cohort studies and seven cross-sectional studies were included. The findings suggested that prolonged sedentary time and usual sedentary bout duration were two metrics that reflected the nonlinear dose-response effect of prolonged sedentary behavior patterns. Only extremely high levels of prolonged sedentary behavior patterns significantly increased the risk of adverse health outcomes, independent of physical activity. Whether prolonged sitting was an additional risk factor for adverse health outcomes, independent of total sedentary time, was inconclusive due to an insufficient number of primary studies that included total sedentary time as one of the potential covariates. There was some evidence that supported a sedentary bout that significantly increased the risk of adverse health outcomes was 30-60 min. The threshold of prolonged sedentary time differed with outcomes, and future studies are needed to make this threshold more precise.

CONCLUSION

A prolonged sedentary behavior pattern was associated with increased risks of several major noncommunicable diseases and all-cause mortality. People, especially those who do not reach the recommended level of moderate-to-vigorous physical activity, are encouraged to interrupt sedentary bouts every 30 to 60 min and limit prolonged sedentary time per day as much as possible.

TWEETABLE ABSTRACT

Breaking up consecutive sedentary bouts >30 to 60 min and substituting them with brief bouts of physical activity.

Changes in Metabolic Health and Sedentary Behavior in Obese Children and Adolescents

Obesity is becoming more common among children and adolescents. As in adults, obesity in the pediatric population is associated with an increased risk of metabolic disorders and diseases. In the related literature, little attention has been devoted to evaluating how metabolic health and sedentary behavior change in the obese pediatric population. Therefore, this study aimed to assess changes in metabolic health and sedentary behavior in obese children aged 7-12 and adolescents aged 13-17. For this single-center hospital-based prospective observational study, we included 202 Polish children and adolescents aged 7-17 years. We performed blood pressure measurements and collected blood samples to assess metabolic health markers. Based on the performed measurements, we also calculated additional indexes and ratios: BMI, WHtR, ABSI, VAI, and HOMA-IR. The analysis of the results showed clear and significant differences between the study groups. The older boys and girls were identified with higher values of anthropometric ratios, blood pressure, time spent sitting, and lower HDL cholesterol values (p < 0.05). The analysis also revealed a strong-to-moderate correlation between age and anthropometric ratios, blood pressure, HDL cholesterol, and sitting time (p < 0.05). Obese children and adolescents included in this study represent poor metabolic health and are at great risk of developing other metabolic diseases such as type 2 diabetes, hypertension, or metabolic syndrome. This risk increases with age; therefore, a number of preventive and therapeutic actions should be taken in overweight and obese children and adolescents to avoid further metabolic complications.

A 24-h activity profile and adiposity among children and adolescents: Does the difference between school and weekend days matter?

BACKGROUND

Twenty-four-hour movement behaviours are gaining attention in the research community. However, no study has addressed how 24-h activity profiles vary between structured and less structured days and whether an unfavourable activity profile is associated with childhood obesity. We aimed to analyse differences between school day and weekend day 24-h activity profiles and their associations with adiposity indicators among children and adolescents.

METHODS

Participants were 382 children and 338 adolescents who wore wrist accelerometers for 24 hours a day for seven consecutive days. The 24-h activity profile expressed by the average acceleration (AvAcc) and intensity gradient (IG) were estimated from multi-day raw accelerometer data. Adiposity indicators included body mass index (BMI) z-score, fat mass percentage (FM%), fat mass index (FMI), and visceral adipose tissue (VAT). Multiple linear regression of activity profile metrics and adiposity indicators was performed separately for school and weekend days.

RESULTS

Weekend days AvAcc and IG were lower compared to school days in both age groups (p <0.001 for all). Specifically, AvAcc was lower by 9.4% and 11.3% in children and adolescents, respectively. IG on weekend days was lower (more negative) by 3.4% in children and 3.1% in adolescents. Among children, on school days AvAcc and IG were negatively associated with FM%, FMI, and VAT, whilst on weekend days AvAcc was positively associated with BMI z-score, FMI, and VAT (p < 0.05 for all). Among adolescents, negative associations were found between weekend day AvAcc and IG and FM% and FMI (p < 0.05 for all), respectively.

CONCLUSIONS

This study confirms the importance of 24-h activity profile as a potentially protective factor against excess adiposity. The variability of movement behaviours during structured and less structured days should be considered when optimizing the 24-h movement behaviours to prevent childhood obesity.

Recent Secular Trends in Child and Adolescent Physical Activity and Sedentary Behavior Internationally: Analyses of Active Healthy Kids Global Alliance Global Matrices 1.0 to 4.0

Background: We examined recent global secular trends in 5 indicators of child and adolescent physical activity and sedentary behavior (Overall Physical Activity, Organized Sport and Physical Activity, Active Play, Active Transportation, and Sedentary Behavior) and 4 influences on these (Family and Peers, School, Community and Environment, and Government). Methods: Active Healthy Kids Global Alliance letter grades (A+ to F) were assigned numbers from 15 to 2, with 0 assigned for missing/incomplete grades. Trends from Active Healthy Kids Global Alliance Global Matrices 1.0 (2014) to 4.0 (2022) were analyzed using linear mixed-effects models with level of economic development and gender inequity considered as potential moderators. Results: Report card grades were generally relatively stable. Trends generally did not differ significantly by level of economic development (except for Active Transportation and Active Play), but gender inequality did significantly moderate trends for most of the indicators, with higher gender inequality associated with more adverse changes in grades. The number of “incomplete” grades decreased over time, but this did not reach statistical significance. Conclusions: While trends varied within and between countries, physical activity and sedentary behaviors, and the influences on these behaviors globally, were relatively stable over the past decade or so, albeit at undesirable levels.

Homes became the "everything space" during COVID-19: impact of changes to the home environment on children's physical activity and sitting

BACKGROUND

During the 2020 UK COVID-19 lockdown restrictions, children spent almost all of their time at home, which had a significant influence on their physical activity (PA) and sedentary behaviour. This study aimed to: 1) determine changes to the social and physical environment at home and children's home-based sitting, PA, standing and sitting breaks as a result of the COVID-19 restrictions; and 2) examine associations between changes at home and children's movement behaviours.

METHODS

One hundred and two children had their PA and sitting, standing and sitting breaks at home objectively measured pre-COVID-19 and during the first COVID-19 lockdown (June-July 2020). Children's parents (n = 101) completed an audit of their home physical environment and a survey on the home social environment at both time points. Changes in the home physical and social environment and behavioural outcomes were assessed using Wilcoxon signed ranked tests, paired t-tests, or chi-square. Repeated linear regression analyses examined associations between changes in homes and changes in the home-based behavioural outcomes.

RESULTS

During COVID-19, households increased the amount of seated furniture and electronic media equipment at home. The number of books and PA equipment decreased and fewer parents enforced a screen-time rule. Children's preference for physical activities and socialising at home decreased. Time at home and sitting at home increased during COVID-19, whilst PA, standing and sitting breaks decreased. Both MVPA and TPA were positively associated with child preference for PA, and negatively associated with attending school. Sitting was negatively associated with child preference for PA and child preference for socialising at home. Media equipment was negatively associated with sitting breaks, whilst PA equipment was positively associated with standing.

CONCLUSION

The COVID-19 restrictions forced children to spend almost all their time at home. Children's PA, standing, and sitting breaks at home declined during the restrictions, while sitting increased. Mostly negative changes occurred in homes, some of which impacted children's behaviours at home. To avoid the changes persisting post-lockdown, interventions are needed to reset and promote children's PA and discourage prolonged sitting time.

Day-level associations of physical activity and sedentary time in mother-child dyads across three years: a multi-wave longitudinal study using accelerometers

Understanding associations between mothers' and children's physical activity and sedentary behavior on more fine-grained timescales can provide insights into real-time intervention opportunities. This study examined the extent to which mothers' and their children's device-measured moderate-to-vigorous physical activity (MVPA) and sedentary time (SDT) were associated at the day level during non-school time. Mother-child dyads (N = 193; baseline Mean ages = 40.69 ± 6.11 [mother] and 9.57 ± 0.89 [child] years) provided 3,135 paired days of accelerometry data from six bi-annual waves across three years. Controlling for covariates, multilevel models revealed that mothers' and their children's MVPA and SDT were positively associated at the day level during non-school time, both on weekdays and weekends. During weekdays, the day-level association for SDT was stronger for older than younger children, and the day-level association for MVPA was stronger for boys than girls. Designing family-based interventions targeting school-age children and their mothers during non-school time across the week may be useful for promoting active lifestyles.

Physical activity and the 'pediatric inactivity triad' in children living with chronic kidney disease: a narrative review

The ‘paediatric inactivity triad’ (PIT) framework consists of three complex inter-related conditions that influence physical inactivity and related health risks. In those living with chronic kidney disease (CKD), a multi-factorial milieu of components likely confound the PIT elements, resulting in a cycle of decreased physical functioning and reduced physical activity. In this review, we explore and summarize previous research on each of the three principal PIT components (exercise deficit disorder, dynapenia, and physical illiteracy) in the pediatric CKD population. We found those living with CKD are significantly physically inactive compared to their peers. Physical inactivity occurs early in the disease process and progressively gets worse as disease burden increases. Although physical activity appears to increase post-transplantation, it remains lower compared to healthy controls. There is limited evidence on interventions to increase physical activity behaviour in this population, and those that have attempted have had negligible effects. Studies reported profound reductions in muscle strength, physical performance, and cardiorespiratory fitness. A small number of exercise-based interventions have shown favourable improvements in physical function and cardiorespiratory fitness, although small sample sizes and methodological issues preclude the generalization of findings. Physical activity must be adapted and individualized to the needs and goals of the children, particularly those with acute and chronic medical needs as is the case in CKD, and further work is needed to define optimal interventions across the life course in this population if we aim to prevent physical activity declining further.

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.

Momentary intentions and perceived behavioral control are within-person predictors of sedentary leisure time: preliminary findings from an ecological momentary assessment study in adolescents

Previous studies among adolescents conceptualize behavioral cognitions [e.g., intentions and perceived behavioral control (PBC)] as stable trait-like factors despite evidence suggesting they vary momentarily. We examined whether intentions and PBC momentarily relate to subsequent sedentary time during non-school periods. Healthy adolescents (N = 15, ages 11-15) reported their intentions and PBC regarding sedentary leisure behaviors via ecological momentary assessment (EMA) up to seven times/day for 14 days. Sedentary time in the two hours following each EMA prompt was measured by ActivPAL accelerometers. When participants reported greater sedentary intentions (within-person β = 1.1, 95% CI 0.2, 2.1, p = 0.0213) and sedentary PBC (within-person β = 1.7, 95% CI 0.6, 2.8, p = 0.0029), they accumulated greater sedentary time. This demonstrates that sedentary intentions and PBC are acutely associated with sedentary time among adolescents. Our findings highlight the potential for implementing just-in-time activity interventions among adolescents during at-risk periods within the day, characterized by deviations from one's usual intentions and PBC levels.

24-Hour Movement Behaviors in Children with Chronic Disease and Their Healthy Peers: A Case-Control Study

Background: Time spent in 24-h movement behaviors is important to health and wellbeing in childhood, but levels of these behaviors in children with chronic disease are unknown. Methods: A case-control-study included 80 children with chronic disease; 20 with type 1 diabetes mellitus (T1DM), 20 with juvenile idiopathic arthritis (JIA), 20 with congenital heart disease (CHD), 20 with cystic fibrosis (CF); pair-matched individually for age, sex, and timing of measures with 80 healthy children. Habitual time spent in movement behaviors and step counts were all measured with an activPAL accelerometer over 7 days. Comparisons against recommendations and differences between the groups were made. Results: Time spent in physical activity and step counts/day were significantly lower in T1DM and CHD groups compared to controls. Only 20/80 children with chronic disease and 29/80 controls met step count recommendations. Sedentary time was significantly higher in children with CF compared to controls. Time spent asleep was slightly greater in children with chronic disease, significant only for the JIA group. Sleep disruption was consistently greater in those with chronic disease, reaching significance for T1DM, CHD, and CF groups. Conclusions: For some groups of children with chronic disease, 24-h movement behaviors may differ substantially from recommendations, and slightly but systematically from their healthy peers. Optimizing levels of 24-h movement behaviors should confer a number of benefits for child health, development, and wellbeing.

Physical Activity in High School Classrooms: A Promising Avenue for Future Research

Adolescence represents a sensitive period whereby lifestyle factors such as physical activity can have profound, long-lasting effects on development and later life habits. However, adolescence constitutes a period of frequent sedentary behaviour. Among children, integrating physical activity into elementary school classrooms has been shown to reduce sedentary behaviour and improve academic achievement and overall physical and mental health. However, this promising area of research has not extended to adolescents and high school classrooms. In this paper, we describe the benefits of conducting research on the impact of physically active high school classrooms, and highlight the challenges and potential misconceptions associated with research in this field. Specifically, we review research on the role of physical activity in adolescent development, the benefits of classroom-based physical activity for children, and discuss the factors that may have led researchers to focus on classroom-based physical activity primarily for children, despite the potentially similar benefits for adolescents.

Changes in sedentary behavior patterns during the transition from childhood to adolescence and their association with adiposity: a prospective study based on compositional data analysis

Background

To date, no longitudinal study using a compositional approach has examined sedentary behavior (SB) patterns in relation to adiposity in the pediatric population. Therefore, our aims were to (1) investigate the changes in SB patterns and adiposity from childhood to adolescence, (2) analyze the prospective compositional associations between changes in SB patterns and adiposity, and (3) estimate the changes in adiposity associated with substituting SB with physical activity (PA) of different intensities.

Methods

The study presents a longitudinal design with a 5-year follow-up. A total of 88 participants (61% girls) were included in the analysis. PA and SB were monitored for seven consecutive days using a hip-worn accelerometer. Adiposity markers (fat mass percentage [FM%], fat mass index [FMI], and visceral adiposity tissue [VAT]) were assessed using the multi-frequency bioimpedance analysis. The prospective associations were examined using compositional data analysis.

Results

Over the follow-up period, the proportion of time spent in total SB increased by 154.8 min/day (p < 0.001). The increase in total SB was caused mainly by an increase in middle and long sedentary bouts, as these SB periods increased by 79.8 min/day and 62.0 min/day (p < 0.001 for both), respectively. FM%, FMI, and VAT increased by 2.4% points, 1.0 kg/m², and 31.5 cm² (p < 0.001 for all), respectively. Relative to the remaining movement behaviors, the increase in time spent in middle sedentary bouts was significantly associated with higher FM% (β_ilr1 = 0.27, 95% confidence interval [CI]: 0.02 to 0.53) at follow-up. Lower VAT by 3.3% (95% CI: 0.8 to 5.7), 3.8% (95% CI: 0.03 to 7.4), 3.9% (95% CI: 0.8 to 6.9), and 3.8% (95% CI: 0.7 to 6.9) was associated with substituting 15 min/week spent in total SB and in short, middle, and long sedentary bouts, respectively, with an equivalent amount of time spent in vigorous PA.

Conclusions

This study showed unfavorable changes in SB patterns and adiposity status in the transition from childhood to adolescence. Incorporating high-intensity PA at the expense of SB appears to be an appropriate approach to reduce the risk of excess adiposity in the pediatric population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-021-00755-5.

Obesity, Lifestyle Behaviors, and Dietary Habits of Saudi Adolescents Living in Riyadh (ATLS-2 Project): Revisited after a Ten-Year Period

Objective: Undesirable lifestyle behaviors are associated with many adverse health outcomes. This study revisited the lifestyle behaviors, dietary habits, and overweight/obesity status of Saudi adolescents from Riyadh during the year 2019/2020. We report on the rationale, design, and methodology of the current study and provide preliminary findings of the changes that occurred between the two cross-sectional studies within the span of a ten-year period. Methods: A comparison was made between two cross-sectional studies, one conducted in 2009/2010 and the other in 2019/2020, using the same design, methods, and instruments. A multistage stratified cluster random sampling technique was used to select adolescents attending public and private secondary schools. Measurements included demographics, weight, height, waist circumference, physical activity (using valid questionnaire and accelerometer), sedentary time, sleep duration, and dietary habits. Results: The total number of participants was 1262 adolescents, of which 52.4% were male, with a mean (SD) age of 16.4 ± 0.95 years. About 41% of paternal and 39.1% of maternal education levels were university degrees. Over 37% of the families earned more than SAR 20,000/month. Body mass index and waist circumference of males was larger than that of females and the overall prevalence of overweight/obesity was 40.5% with significance (p < 0.001) difference between males (47.3%) and females (32.8%). Between 2009/2010 and 2019/2020 datasets, there were significant changes in age (p < 0.001), waist circumference (p < 0.001), screen time (p < 0.001), moderate-intensity physical activity (p < 0.001), vigorous-intensity physical activity (p < 0.001), total physical activity (p < 0.001), and consumption of breakfast (p = 0.015) and fruits (p = 0.002). Conclusion: The most notable change between the two studies was a significant reduction in the prevalence of physical inactivity among Saudi adolescents, which was due to increased levels of moderate-intensity physical activity among Saudi females, as a result of recent positive sociopolitical changes occurring in the country over the past four years. The findings provided rich information that can be used to explore trends in overweight/obesity, lifestyle behaviors, and dietary habits among Saudi adolescents over the past ten-year period.

Influence of Parenting Style on Body Mass Index, Physical Activity, and Sedentary Time

The purpose of the current study was to determine the influence of parenting style on body mass index (BMI) percentile, physical activity (PA), and sedentary time (ST) in children. Accelerometers were used to assess PA and ST in 152 fifth-grade children. Parenting style was assessed by the child participants’ responses to modified questions from the Parenting Style Inventory II and dichotomized as authoritative or non-authoritative. Multiple linear regression analyses were utilized to identify significant predictors of outcomes of interest. Parenting style did not predict ST or any intensity of PA; however, BMI percentile and gender were significant predictors of moderate-intensity PA, vigorous-intensity PA, and moderate-to-vigorous intensity PA (P < .01). BMI percentile was predicted to be lower in females with authoritative mothers (P < .01). While authoritative and non-authoritative parenting style did not predict objectively measured PA or ST in early adolescents, authoritative parenting style did predict BMI percentile in female participants.

Associations between physical activity, sedentary time and cardiovascular risk factors among Dutch children

Introduction

Physical activity (PA) plays an important role in the prevention of cardiovascular diseases, especially in children. Previous studies which investigated the role of PA and sedentary time (ST) in cardiovascular disease used different measurements and found inconsistent results. The current study used recommended standardized measures and provides an overview of PA and ST among Dutch primary school children and their associations with cardiovascular risk factors.

Methods

503 children (55% girls, mean age (± SD) 10 ± 1y) were included. PA (total PA, lightPA and moderate to vigorous PA (MVPA)) and ST were measured with the Actigraph GT3X accelerometer. PA in different domains was measured with the BAECKE questionnaire. Cardiovascular risk factors included BMI z-score, waist circumference, blood pressure (z-score) and estimated cardiorespiratory fitness (CRF) as measured with the 20 meter shuttle run test.

Results

Children spent 57 ± 20 min/day (8%) on MVPA and 42% of the children reached the MVPA guideline of 60 min/day. Total PA and MVPA (h/day) were negatively associated with BMI z-score (B = -0.452, p = 0.011) and waist circumference (B = -3.553, p = 0.011) and positively associated with CRF (B = 2.527, p = <0.001). ST was positively associated with BMI z-score (B = 0.108, p = 0.048) and waist circumference (B = 0.920, p = 0.033). No significant associations were found between total PA or PA intensities and blood pressure.

Conclusion

This study used standardized measures of PA and therefore created an accurate overview of PA, ST and their associations with cardiovascular risk factors. PA and ST were associated with BMI z-score, waist circumference and CRF. The findings emphasize the importance of promoting MVPA in children, but also highlight the potential benefits of reducing ST to improve cardiovascular risk factors.

Trial registration

ClinicalTrials.gov NCT03440580.

Age-varying Bi-directional Associations Between Momentary Affect and Movement Behaviors in Children: Evidence From a Multi-wave Ecological Momentary Assessment Study

BACKGROUND

The bi-directional associations between affective states and movement behaviors (e.g., physical activity, sedentary behavior) have been observed in children. It is unclear if the strength of these bi-directional associations varies with age as children transition from childhood to adolescence.

PURPOSE

This multi-wave ecological momentary assessment (EMA) study investigates the acute time-varying associations between affect and movement behaviors among youth.

METHODS

Children (N = 195, baseline mean age = 10.72, range = 8-12 years, mean BMI-z = 0.49, 51% female) participated in a six-wave EMA study across three years. Each EMA survey captured momentary positive and negative affect. Time spent in moderate-to-vigorous physical activity (MVPA) and sedentary time in the 15-min window before and after each EMA survey was calculated using accelerometry data. Time-varying effect models (TVEM) examined the acute bi-directional associations between momentary positive/negative affect and MVPA/sedentary time across ages 8 to 14.

RESULTS

Children provided 14,246 valid activity-matched EMA surveys across all waves. TVEM plots revealed that the directionality and the strength (time-varying slopes) of associations between momentary affect and activity levels vary across ages. Positive affect was associated with higher MVPA levels and lower sedentary time at younger ages, whereas negative affect linked to lower MVPA levels and more sedentary time at older ages.

CONCLUSIONS

The acute associations between momentary affect and (in)activity levels may vary as a function of children's age. Applying TVEM to intensive longitudinal data could provide valuable information for developing age-tailored interventions that promote healthy lifestyles among children and adolescents.

The use of coping strategies "shift-persist" mediates associations between physical activity and mental health problems in adolescents: a cross-sectional study

Background

Self-perceived mental health problems among adolescents has had an upward trend. Concurrently, adolescents’ physical activity (PA) has been falling whilst sedentary time (SED) has increased. There is a lack of research using accelerometer measured PA and SED to study their relationships to perceived stress and psychosomatic symptoms, both frequently observed mental health problems among adolescents. Whether coping strategies is one of the mechanisms underlying such relationship is less clear.

Methods

A total of 2283 13-year olds were enrolled in the baseline examination of the STARS (STudy of Adolescence Resilience and Stress) study in Western Sweden. Light-, moderate-, vigorous-intensity PA (LPA, MPA and VPA) and SED were measured using hip-worn ActiGraph GT3X+ accelerometer. A total of 1284 adolescents provided valid accelerometer data (at least 4 days with ≥10 h per day). PA and SED during school-time and leisure-time were analysed separately. Surveys were utilized to monitor perceived stress, psychosomatic symptoms and the use of coping strategies “shift-persist”. Logistic regression and mediation analyses were performed adjusting for gender, ethnicity, socioeconomic status and puberty development.

Results

We observed that more time spent in PA was associated with less stress in adolescents. The associations were observed for LPA (Odds ratio for LPA per 60 min: 0.557 (95% CI 0.399–0.776), VPA (Odds ratio for VPA per 15 min: 0.688 (95% CI 0.588–0.806) and MVPA (Odds ratio for MVPA per 15 min: 0.795 (95%CI 0.718–0.879) during leisure time, but not during school time. Similar associations were observed between leisure time PA and psychosomatic symptoms. The associations remained statistically significant even after adjusting for the confounders. Further, our data showed that adolescents who engaged more time in PA during leisure time were more likely to adopt the coping strategies of “shift-persist”. Mediation analysis showed that the use of “shift-persist” mediated the associations between leisure time PA and stress/psychosomatic symptoms.

Conclusions

Leisure time physical activity, irrespective of intensity, may facilitate successful coping with stress and stress-related mental health problems in adolescents.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11158-0.

Effects of Classroom Active Desks on Children and Adolescents' Physical Activity, Sedentary Behavior, Academic Achievements and Overall Health: A Systematic Review

The purpose of this systematic review was to examine the effects of active desks in the school setting on sedentary behavior, physical activity, academic achievements and overall health among children and adolescents aged 5-17 years. A systematic literature search was conducted using five databases until October 2020. Twenty-three studies were included. Studies reported an increase of around 36% in energy expenditure for cycling desks and between 15% and 27.7% for upright active desks. Children increased inhibitory control and selective attention capacity while using cycling desks. A heterogeneous quality of design and of results were observed limiting comparisons and conclusions for each active desk. Despite the lack of strong methodology for the included studies, active desks appear to be a promising intervention in classrooms to improve health-related outcomes in children aged 5-17 years. Due to weak methodology, future studies with stronger study designs and methodology are needed to better inform policy and practice about the role of classroom active desks on health-related outcomes in children and adolescents.

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.

Latent Class Analysis of Lifestyle Risk Factors and Association with Overweight and/or Obesity in Children and Adolescents: Systematic Review

Background: Multiple modifiable lifestyle factors are well-known contributors to many health problems. Objectives: This study aims to determine the association between latent class analysis (LCA) of modifiable lifestyle risk factors with being overweight and/or obese for children and/or adolescents. Methods: Articles were selected from six databases, without limitation regarding language or date. The review included studies that identify latent classes of modifiable lifestyle risk factors [e.g., physical activity (PA), diet, sedentary behavior (SB), and/or unhealthy behavior] by LCA to determine the association between latent classes with being overweight and/or obese. The methodology of the selected studies was evaluated using the JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies. Owing to the heterogeneity between latent classes of modifiable lifestyle risk factors with obesity and/or being overweight, the results are described narratively. Results: Using a selection process in two phases, nine articles were included. All of the included studies were of high methodological quality. The studies were conducted in six different countries: the USA, Brazil, Canada, Portugal, Italy, and Australia. Sample sizes ranged from 166 to 18.587 children and adolescents, and in terms of age (range 5-19 years). Across study clusters characterized by low consumption of fruit and vegetables, and high consumption of fatty foods, sugar snack foods, sweets, chips and fries, low PA (<1 hour each day), and high SB (screen time and TV >2 hours/day), sleep time (<10 hours/day) were positively associated with being overweight and/or obese. Conclusion: Overall there is good evidence to support that the modifiable lifestyle risk factors clustered together by LCA should be novel targets for the treatment of obesity and its associated comorbidities.

Intervention Effects of the Health Promotion Programme "Join the Healthy Boat" on Objectively Assessed Sedentary Time in Primary School Children in Germany

Sedentary behaviour (SB) in children is related to negative health consequences that can track into adulthood. The programme "Join the Healthy Boat" promotes reduced screen time and a less sedentary lifestyle in schoolchildren. This study investigated the effects of the programme on children's SB. For one year, teachers delivered the programme. A total of 231 children (7.0 ± 0.6 years) participated in the cluster-randomised study; there were 154 one year later at follow-up. Children's SB was assessed using multi-sensor accelerometery, screen time via parental questionnaire. Effects were analysed using (linear) mixed effects regression models. At baseline, children spent 211 (±89) min daily in SB, at follow-up 259 (±109) min/day with no significant difference between the intervention (IG) and control group (CG). SB was higher during weekends (p < 0.01, for CG and IG). However, at follow-up, daily screen time decreased in IG (screen time of >1 h/day: baseline: 33.3% vs. 27.4%; follow-up: 41.2% vs. 27.5%, for CG and IG, respectively). This multi-dimensional, low-threshold intervention for one year does not seem to achieve a significant reduction in children's SB, although screen time decreased in IG. Therefore, it should be considered that screen time cannot be the key contributor to SB and should not solely be used for changing children's SB. However, if screen time is targeted, interventions should promote the replacement of screen time with active alternatives.

Electronic Devices as Correlates of Sedentary Behavior and Screen Time Among Diverse Low-Income Adolescents During the School Year and Summer Time

Excessive screen time among adolescents increases risk for overweight and obesity. Having electronic devices in the adolescent's bedroom is associated with more screen time. The present study expanded on previous studies by also examining portable personal electronic devices and social media membership as correlates of screen time use and total sedentary time in the school year and summer among diverse low-income adolescents. Adolescents aged 10-17 years were recruited from lower-income areas; n=150 (34 African Americans, 23 American Indians, 16 Asian/Pacific Islanders, 39 Latinos, and 38 White/non-Hispanics) completed surveys and wore accelerometers in both the school year and summer. Total sedentary time was computed from accelerometers. Recreational screen time was assessed with a 3-item validated scale. Adolescents reported the presence of 6 electronic devices in their bedrooms, ownership of 4 portable devices, and social media membership. General linear modeling was conducted for both time periods, with demographic covariates and interactions with sex and race/ethnicity. More electronic devices in bedrooms were related to more screen time during the school year and summer, and to more total sedentary time in summer. Personal electronics were related only to more screen time in the school year. Social media membership was related to more total sedentary time in summer, but only among African Americans, American Indians, and non-Hispanic Whites. Electronic devices in bedrooms was confirmed as a risk factor for sedentary behavior among low-income adolescents of color. Social media membership and use should be further studied with diverse adolescents.

Longitudinal Changes in Children's Accelerometer-derived Activity Pattern Metrics

PURPOSE

The objective of this study was to quantify age-related changes in accelerometer-derived day-level physical activity and sedentary behavior pattern metrics (i.e., number, length, and temporal dispersion of bouts and breaks) across 3 yr of middle childhood. Differences by child sex and weekend versus weekday were examined.

METHOD

Children (N = 169, 54% female, 56% Hispanic; 8-12 yr old at enrollment) participated in a longitudinal study with six assessments across 3 yr. Day-level moderate-to-vigorous physical activity (MVPA; i.e., total minutes, number of short (<10 min) bouts, proportion of long (≥20 min) bouts, temporal dispersion) and sedentary behavior (i.e., total minutes, number of breaks, proportion of long (≥60 min) bouts, temporal dispersion) pattern metrics were measured using a waist-worn accelerometer (Actigraph GT3X).

RESULTS

Random intercept multilevel linear regression models showed that age-related decreases in the number of short MVPA bouts per were steeper for girls than for boys (b = -1.28; 95% confidence interval (CI), -1.93 to -0.64; P < 0.01) and on weekend days than on weekdays (b = -1.82; 95% CI, -2.36 to -1.29; P < 0.01). The evenness of the temporal dispersion of MVPA across the day increased more on weekend days than on weekdays as children got older (b = -0.02; 95% CI, -0.02 to -0.01; P < 0.01). Girls had steeper age-related decreases in the number of sedentary breaks per day (b = -2.89; 95% CI, -3.97 to -1.73; P < 0.01) and the evenness of the temporal dispersion of sedentary behavior across the day (b ≤ 0.01; 95% CI, <0.01 to 0.01; P < 0.01) than did boys. Changes in sedentary behavior metrics did not differ between weekend days and weekdays.

CONCLUSION

Strategies to protect against declines in short physical activity bouts and promote sedentary breaks, especially among girls and on weekend days, could reduce cardiometabolic risks.

Impacts of a Standing Desk Intervention within an English Primary School Classroom: A Pilot Controlled Trial

Traditional classroom furniture dictates that children predominantly sit during class time. This study evaluated the impact of providing standing desks within a deprived UK primary school setting over 8 months using mixed-method approaches. All children within a Year 5 class (9–10-year-olds, n = 30) received an adjustable sit–stand desk, while another Year 5 class (n = 30) in a nearby school retained traditional furniture as a control classroom. At baseline, 4 months, and 8 months, activPAL monitors (PAL Technologies, Glasgow, UK) were worn for 7 days to provide time spent sitting and standing. Behavior-related mental health, musculoskeletal discomfort surveys, and a cognitive function test battery were also completed at all three timepoints. Intervention experiences from pupils and the teacher were captured using focus groups, interviews, and classroom observations. At both 4 months and 8 months, multi-level models revealed a reduction in class time sitting in the intervention group compared to the control group ((β (95%CI) 4 months −25.3% (−32.3, −18.4); 8 months −19.9% (−27.05, −12.9)). Qualitative data revealed challenges to teaching practicalities and a gradual decline in behavior-related mental health was observed (intervention vs. control: 4 months +5.31 (+2.55, +8.08); 8 months +7.92 (+5.18, +10.66)). Larger trials within similar high-priority settings are required to determine the feasibility and cost-effectiveness of providing standing desks to every child in the classroom.

School-Based Multicomponent Intervention to Promote Physical Activity and Reduce Sedentary Time of Disadvantaged Children Aged 6-10 Years: Protocol for a Randomized Controlled Trial

Background

In our modern society, physical activity (PA) is decreasing and sedentary time (ST) is increasing, especially for children from disadvantaged neighborhoods. School-based interventions to promote PA and decrease ST are therefore required among this population in order to change children’s lifestyle habits. Moreover, attentional capacities and academic achievement can be enhanced by chronic PA during childhood. The relationships between these variables have been poorly studied with this population.

Objective

The objective of this study is to present the rationale and methods for a randomized controlled trial among 6-10-year-old children with low socioeconomic status that will (1) evaluate the effectiveness of a school-based intervention designed to promote PA and reduce ST and (2) study the relationships between PA, ST, motor skills, attentional capacities, and academic achievement.

Methods

A randomized controlled trial was conducted in 2 eligible primary schools. During academic year 2016-2017, 1 school was randomly assigned as the experiment one and the other was assigned as the control one. Five assessments times were used: baseline (T1 [November 2016] to T2 [June 2017]), follow-up (T3 [November 2017] to T4 [June 2018]), and final assessment (T5 [June 2019]). The school-based intervention included various components on different levels of the socioecological model: (1) curriculum-based program for children; (2) sensitization workshops and newsletters for parents; (3) training workshops for teachers; (4) environmental adaptation of playgrounds and reorganization of recess time; (5) time adaptation of lunch breaks; and (6) collaboration with political groups. PA, ST, motor skills, and attentional capacities were evaluated and academic achievement was recorded.

Results

The presented intervention and its different assessments have been successfully implemented. In order to achieve the 2 objectives of this randomized controlled trial, data analyses are about to be completed.

Conclusions

The implementation of this randomized controlled trial can help to determine effective strategies to promote PA in the context of increasing prevalence of physical inactivity among children with sedentary lifestyle which will be useful for researchers, stakeholders, and public policy makers.

Trial Registration

ClinicalTrials.gov NCT03983447; https://clinicaltrials.gov/ct2/show/NCT03983447

International Registered Report Identifier (IRRID)

RR1-10.2196/17815

Validation of the Activity Preference Assessment: a tool for quantifying children's implicit preferences for sedentary and physical activities

BACKGROUND

High levels of sedentary behavior and low physical activity are associated with poor health, and the cognitive determinants of these behaviors in children and adolescents are not well understood. To address this gap, we developed a novel, non-verbal, computer-based assessment to quantify the degree to which youth prefer to be sedentary relative to physically active in their leisure time.

METHODS

The Activity Preference Assessment (APA) uses a forced-choice paradigm to understand implicit decision-making processes when presented with common sedentary and physical activities. The APA bias score ranges from - 100 to + 100, with positive scores indicating a relative preference for sedentary activities, and negative scores representing a preference for physical activities. In 60 children ages 8-17 years, we assessed the validity of this behavioral task against a free-choice play observation, accelerometry-measured activity, anthropometrics and body composition, and cardiorespiratory fitness. We explored neighborhood, family, and individual-level factors that may influence implicit activity preferences. Test-retest reliability was assessed over one week.

RESULTS

The majority of children (67%) preferred sedentary relative to physical activities. APA bias scores were positively associated with sedentary time during free-choice play. In girls, bias scores were negatively associated with average daily MVPA. APA bias scores were positively associated with body fat and negatively associated with cardiorespiratory fitness. These findings were independent of age, sex, and race/ethnicity. Neighborhood access to physical activity spaces, the number of people in the home, perceived physical self-competence (e.g., coordination, strength), and self-reported depressive symptoms were associated with activity preferences. The intra-class correlation for test-retest reliability was r = 0.59.

CONCLUSIONS

The APA shows promise as a novel tool for quantifying children's relative preference for sedentary versus physical activities. Implicit bias scores from the APA are clinically meaningful, as shown by significant associations with adiposity and cardiorespiratory fitness. Future longitudinal studies should examine the directionality of the association between preferences and health markers, and the degree to which implicit activity preferences are modifiable. Importantly, the task only takes an average of 10 min to complete, highlighting a potential role as an efficient screening tool for the propensity to be sedentary versus physically active.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03624582 .

Effects of Installing Height-Adjustable Standing Desks on Daily and Domain-Specific Duration of Standing, Sitting, and Stepping in 3rd Grade Primary School Children

Background: Aim of this intervention study was to evaluate whether availability of standing desks in classrooms may reduce sitting time and enhance standing and stepping time during lessons and breaks. Further, we evaluated if differences in standing desk use differed by physical fitness (PF) levels of children.

Methods: To assess sitting, standing and stepping during a typical school week in 3rd grade primary school children (N = 52), activPAL monitors were used at baseline: T0, 1st follow-up: T1 and 2nd follow-up: T2. At baseline, PF was measured using the standing long jump and the 6-min jog-walk to assign children as having low PF (LPF) or high PF (HPF). Standing desks were assigned randomly to intervention and control groups at T1 (group 1) and T2 (group 2) with a cross-over design. Changes of sitting, standing and stepping were analyzed to investigate intervention effects at follow-up, using linear mixed models.

Results: At baseline, children spent about 60 and 30% of time sitting during lessons and breaks, respectively. After installing standing desks (T1), significantly lower proportions of sitting were observed in the intervention group 1 [−13.1%, 95%-CI: (−20.5; −5.72)] and the control group 2 [−9.78%, 95%-CI: (−17.3; −2.28)]. Compared to the baseline measurement (T0), lower proportions of sitting were particularly expressed during school breaks in group 1 and 2 after intervention in T1 [group 1: −10.3%, 95%-CI: (−16.4; −4.25)] or in T2 [group 2: −8.59%, 95%-CI: (−15.2; −1.94)]. In general, children with higher physical fitness were less sedentary and more active, but intervention effects did not differ by fitness levels.

Conclusion: Standing desks provide an opportunity to reduce sedentary time during lessons and breaks at school in primary school children, but do not directly increase PA of high intensity such as stepping. Future studies should consider potential bandwagon effects caused by structural interventions.

Temporal trends in leisure-time sedentary behavior among adolescents aged 12-15 years from 26 countries in Asia, Africa, and the Americas

Background

Multi-country studies examining trends in sedentary behaviors among adolescents have mainly focused on high-income or Western countries, and almost no data exists for the rest of the world. Thus, this study aims to examine temporal trends in adolescents’ leisure time sedentary behavior (LTSB) employing nationally representative datasets from 26 countries from five WHO-defined geographical regions.

Methods

Data from the Global School-based Student Health Survey 2003–2017 were analyzed in 17,734 adolescents [mean (SD) age: 13.7 (1.0) years; 49.0% boys]. LTSB was self-reported and included all types of sedentary behaviors, excluding time spent at school or doing homework. The prevalence and 95%CI of high LTSB (i.e., ≥3 h/day) was calculated for the overall sample and by sex for each survey. Crude linear trends in high LTSB were assessed by linear regression models. Interaction analyses were conducted to examine differing trends among boys and girls.

Results

Temporal variations in LTSB substantially diverged across countries, with results showing increasing (6/26 countries), decreasing (4/26) and stable trends. The sharpest increases in LTSB occurred in United Arab Emirates, Kuwait, and Thailand. Some countries did not show an increase in LTSB prevalence over time but had very high levels of LTSB (i.e., > 40%) across multiple years. Most countries showed no differences in LTSB trends between boys and girls.

Conclusions

Data from our study may serve as an important platform for policymakers, as well as local and national stakeholders, to establish country-specific and tailored strategies for reducing LTSB.

Cardiorespiratory Fitness in Youth: An Important Marker of Health: A Scientific Statement From the American Heart Association

Cardiorespiratory fitness (CRF) refers to the capacity of the circulatory and respiratory systems to supply oxygen to skeletal muscle mitochondria for energy production needed during physical activity. CRF is an important marker of physical and mental health and academic achievement in youth. However, only 40% of US youth are currently believed to have healthy CRF. In this statement, we review the physiological principles that determine CRF, the tools that are available to assess CRF, the modifiable and nonmodifiable factors influencing CRF, the association of CRF with markers of health in otherwise healthy youth, and the temporal trends in CRF both in the United States and internationally. Development of a cost-effective CRF measurement process that could readily be incorporated into office visits and in field settings to screen all youth periodically could help identify those at increased risk.

Tracking of total sedentary time and sedentary patterns in youth: a pooled analysis using the International Children's Accelerometry Database (ICAD)

Background

To gain more understanding of the potential health effects of sedentary time, knowledge is required about the accumulation and longitudinal development of young people’s sedentary time. This study examined tracking of young peoples’ total and prolonged sedentary time as well as their day-to-day variation using the International Children’s Accelerometry Database.

Methods

Longitudinal accelerometer data of 5991 children (aged 4-17y) was used from eight studies in five countries. Children were included if they provided valid (≥8 h/day) accelerometer data on ≥4 days, including ≥1 weekend day, at both baseline and follow-up (average follow-up: 2.7y; range 0.7–8.2). Tracking of total and prolonged (i.e. ≥10-min bouts) sedentary time was examined using multilevel modelling to adjust for clustering of observations, with baseline levels of sedentary time as predictor and follow-up levels as outcome. Standardized regression coefficients were interpreted as tracking coefficients (low: < 0.3; moderate: 0.3–0.6; high: > 0.6).

Results

Average total sedentary time at study level ranged from 246 to 387 min/day at baseline and increased annually by 21.4 min/day (95% confidence interval [19.6–23.0]) on average. This increase consisted almost entirely of prolonged sedentary time (20.9 min/day [19.2–22.7]). Total (standardized regression coefficient (B) = 0.48 [0.45–0.50]) and prolonged sedentary time (B = 0.43 [0.41–0.45]) tracked moderately. Tracking of day-to-day variation in total (B = 0.04 [0.02–0.07]) and prolonged (B = 0.07 [0.04–0.09]) sedentary time was low.

Conclusion

Young people with high levels of sedentary time are likely to remain among the people with highest sedentary time as they grow older. Day-to-day variation in total and prolonged sedentary time, however, was rather variable over time.

Sedentary behavior patterns and adiposity in children: a study based on compositional data analysis

BACKGROUND

Between-person differences in sedentary patterns should be considered to understand the role of sedentary behavior (SB) in the development of childhood obesity. This study took a novel approach based on compositional data analysis to examine associations between SB patterns and adiposity and investigate differences in adiposity associated with time reallocation between time spent in sedentary bouts of different duration and physical activity.

METHODS

An analysis of cross-sectional data was performed in 425 children aged 7-12 years (58% girls). Waking behaviors were assessed using ActiGraph GT3X accelerometer for seven consecutive days. Multi-frequency bioimpedance measurement was used to determine adiposity. Compositional regression models with robust estimators were used to analyze associations between sedentary patterns and adiposity markers. To examine differences in adiposity associated with time reallocation, we used the compositional isotemporal substitution model.

RESULTS

Significantly higher fat mass percentage (FM%; β_ilr1 = 0.18; 95% CI: 0.01, 0.34; p = 0.040) and visceral adipose tissue (VAT; β_ilr1 = 0.37; 95% CI: 0.03, 0.71; p = 0.034) were associated with time spent in middle sedentary bouts in duration of 10-29 min (relative to remaining behaviors). No significant associations were found for short (< 10 min) and long sedentary bouts (≥30 min). Substituting the time spent in total SB with moderate-to-vigorous physical activity (MVPA) was associated with a decrease in VAT. Substituting 1 h/week of the time spent in middle sedentary bouts with MVPA was associated with 2.9% (95% CI: 1.2, 4.6), 3.4% (95% CI: 1.2, 5.5), and 6.1% (95% CI: 2.9, 9.2) lower FM%, fat mass index, and VAT, respectively. Moreover, substituting 2 h/week of time spent in middle sedentary bouts with short sedentary bouts was associated with 3.5% (95% CI: 0.02, 6.9) lower FM%.

CONCLUSIONS

Our findings suggest that adiposity status could be improved by increasing MVPA at the expense of time spent in middle sedentary bouts. Some benefits to adiposity may also be expected from replacing middle sedentary bouts with short sedentary bouts, that is, by taking standing or activity breaks more often. These findings may help design more effective interventions to prevent and control childhood obesity.

Are There Any Differences between First Grade Boys and Girls in Physical Fitness, Physical Activity, BMI, and Sedentary Behavior? Results of HCSC Study

The transition from kindergarten to school is associated with a variety of negative changes. After entry to elementary school physical activity level decreases. Moreover, physical fitness level of children over the past decades have rapidly declined. Children are spending an increasing amount of time in the environments that require constant sitting. We evaluated the differences between boys and girls in physical fitness, frequency of undertaking of different forms of physical activity, prevalence of underweight and overweight, and time spent on sedentary behavior. A total of 212 first grade pupils (mean age 6.95 ± 0.43) from two standard urban schools in Poznań participated in the study. Compared to girls, boys obtained better results in 20-meter run (4.9 s and 5.0 s, p < 0.01), sit-ups (16.8 and 15.3, p < 0.05), six-minute run (829.7 m and 766.4 m, p < 0.001), and standing broad jump (106.8 cm and 99.7 cm, p < 0.01). In the sit-and-reach test girls achieved higher results than boys (17.0 cm and 14.4 cm, p < 0.001). There were no gender differences in prevalence of underweight and overweight. In conclusions, difference between genders should be taken into consideration during designing physical activity programs in the aspects of intensity and forms of physical activities.

A good beginning: study protocol for a group-randomized trial to investigate the effects of sit-to-stand desks on academic performance and sedentary time in primary education

BACKGROUND

Sedentary behavior is associated with health risks and academic under-achievement in children. Still, children spend a large part of their waking hours sitting at a desk at school. Recent short-term studies demonstrated the potential of sit-to-stand desks to reduce sitting time in primary education. The program of "A Good Beginning" was conceived to assess the long-term effects of sit-to-stand desks on sitting time in primary education, and to examine how sit-to-stand desks versus regular desks relate to academic performance, and measures of executive functioning, health and wellbeing. The present paper describes the design of this group-randomized trial, which started in 2017 and will be completed in 2019.

METHODS

Children of two grade-three groups (age 8-9) following regular primary education in Leiden, The Netherlands, were recruited. A coin toss determined which group is the experimental group; the other group is the control group. All children in the experimental group received sit-to-stand desks. They are invited and motivated to reduce sedentary time at school, however, it is their own choice to sit or stand. Children in the control group use regular desks. Otherwise, both groups receive regular treatment. Outcomes are assessed at baseline (T0) and at five follow-up sessions (T1-T5) alternately in winter and summer seasons over three academic years. Primary outcome measures are academic performance, and the proportion of sitting time at school, measured with a 3D accelerometer. Secondary outcome measures are a number of measures related to executive functioning (e.g., N-back task for working memory), health (e.g., height and weight for BMI), and wellbeing (e.g., KIDSCREEN-52 for Quality of Life).

DISCUSSION

A Good Beginning is a two-and-a-half-year research program, which aims to provide a better understanding of the long-term effects of sit-to-stand desks on sedentary time at school and the relation between sitting time reduction and academic performance, executive functioning, health and wellbeing. The findings may serve as useful information for policy making and practical decision making for school and classroom environments.

TRIAL REGISTRATION

The program of "A Good Beginning" is registered at the Netherlands Trial Register (NTR, https://www.trialregister.nl), number NL6166, registration date 24 November 2016.

Longitudinal changes in moderate-to-vigorous-intensity physical activity in children and adolescents: A systematic review and meta-analysis

Moderate-to-vigorous-intensity physical activity (MVPA) is important for childhood obesity prevention and treatment, yet declines with age. Timing and magnitude of the decline in MVPA in children and adolescents are unclear but important for informing effective obesity intervention development. This systematic review aimed to determine and compare the year-to-year changes in MVPA among children and adolescents. Longitudinal studies were identified by searching 10 relevant databases up to December 2018. Studies were eligible for inclusion if they reported accelerometer-assessed MVPA (min day^-1 ) separately for boys and girls and had follow-up duration of at least 1 year. After screening 9,232 studies, 52 were included representing 22,091 aged 3 to 18 year olds (boys=8,857; girls=13,234). Pooled-analysis of the relative change in MVPA per year showed a decline of -3.4% (95% CI, -5.9 to -0.9) in boys and -5.3% (95% CI, -7.6 to -3.1) in girls, across all age groups. There were notable declines in MVPA at age 9 for both boys (-7.8%, 95% CI, -11.2 to -4.4) and girls (-10.2%, 95% CI, -14.2 to -6.3). The relative decline in MVPA affects both sexes from an early age; however, it is greater among girls. Interventions to promote MVPA should start before adolescence.

GRADE-ADOLOPMENT Process to Develop 24-Hour Movement Behavior Recommendations and Physical Activity Guidelines for the Under 5s in the United Kingdom, 2019

Background: This article summarizes the approach taken to develop UK Chief Medical Officers’ physical activity guidelines for the Under 5s, 2019. Methods: The Grading of Recommendations Assessment, Development and Evaluation (GRADE)-Adaptation, Adoption, De Novo Development (ADOLOPMENT) approach was used, based on the guidelines from Canada and Australia, with evidence updated to February 2018. Recommendations were based on the associations between (1) time spent in sleep, sedentary time, physical activity, and 10 health outcomes and (2) time spent in physical activity and sedentary behavior on sleep outcomes (duration and latency). Results: For many outcomes, more time spent in physical activity and sleep (up to a point) was beneficial, as was less time spent in sedentary behavior. The authors present, for the first time, evidence in GRADE format on behavior type–outcome associations for infants, toddlers, and preschoolers. Stakeholders supported all recommendations, but recommendations on sleep and screen time were not accepted by the Chief Medical Officers; UK guidelines will refer only to physical activity. Conclusions: This is the first European use of GRADE-ADOLOPMENT to develop physical activity guidelines. The process is robust, rapid, and inexpensive, but the UK experience illustrates a number of challenges that should help development of physical activity guidelines in future.

Adolescent Body Dissatisfaction in Contrasting Socioeconomic Milieus, Coming from a French and Luxembourgish Context

Purpose: To analyze the relationships between body mass index (BMI), ideal body, current declared body shape, and gap between ideal and declared body shape, and the associations that these have with social and cultural factors among 329 adolescents (11 to 15 years i.e., at two stages of adolescence, the early and late adolescence), attending an international school in Luxembourg, and 281 from Paris. Methods: A cross-sectional survey was conducted using an online questionnaire. Missing data were addressed using the data augmentation method in a Bayesian framework. Results: For both sets, higher the BMI and bigger their current body shape (CBS), the slimmer their ideal body shape, especially for those who perceive a link between body shape and beauty. For girls, slimness is a shared ideal; for boys, older they are, more they want a muscular body shape. Most students want slimmer bodies, but in affluent or intermediate social milieu students in relations to identification to personalities such as celebrities, while students from modest milieus, this is expressed in relation to success in love. In addition, they declared that their “talk diet with friends” were associated with large gap between ideal and declared body shape. Conclusions: A social control norm was revealed involving a displacement of values affecting body weight and health in the late stage of adolescence to early adolescence, especially for boys.

Overweight and obesity in sexual and gender minority adolescents: A systematic review

Population data indicate that sexual and gender minority adolescents may be at increased risk for excess weight gain compared with cisgender, heterosexual youth. However, no studies, to our knowledge, have systematically reviewed the literature on weight disparities in this population nor explored risk for overweight and obesity by sexual and gender minority subgroup across studies. The current systematic review, therefore, identified 21 studies that assessed the relationship between sexual and gender minority status and weight among adolescents. Results indicated an overall greater prevalence of overweight and obesity among sexual and gender minority adolescents compared with cisgender, heterosexual youth. However, cisgender sexual minority males demonstrated lower or no added risk for overweight and obesity, whereas cisgender sexual minority females demonstrated greater risk for overweight and obesity. Findings were mixed among gender minority adolescents. This study highlights weight disparities in sexual and gender minority youth, although important subgroup differences exist. Additional research is needed to elucidate the mechanisms that may contribute to differential weight trajectories in this population and to develop tailored approaches for prevention and treatment.

Sedentary Behaviors in Today's Youth: Approaches to the Prevention and Management of Childhood Obesity: A Scientific Statement From the American Heart Association

This scientific statement is about sedentary behavior and its relationship to obesity and other cardiometabolic outcomes in youth. A deleterious effect of sedentary behavior on cardiometabolic health is most notable for screen-based behaviors and adiposity; however, this relation is less apparent for other cardiometabolic outcomes or when sedentary time is measured with objective movement counters or position monitors. Increasing trends of screen time are concerning; the portability of screen-based devices and abundant access to unlimited programming and online content may be leading to new patterns of consumption that are exposing youth to multiple pathways harmful to cardiometabolic health. This American Heart Association scientific statement provides an updated perspective on sedentary behaviors specific to modern youth and their impact on cardiometabolic health and obesity. As we reflect on implications for practice, research, and policy, what emerges is the importance of understanding the context in which sedentary behaviors occur. There is also a need to capture the nature of sedentary behavior more accurately, both quantitatively and qualitatively, especially with respect to recreational screen-based devices. Further evidence is required to better inform public health interventions and to establish detailed quantitative guidelines on specific sedentary behaviors in youth. In the meantime, we suggest that televisions and other recreational screen-based devices be removed from bedrooms and absent during meal times. Daily device-free social interactions and outdoor play should be encouraged. In addition, parents/guardians should be supported to devise and enforce appropriate screen time regulations and to model healthy screen-based behaviors.

Associations of Sitting Behavior Patterns With Cardiometabolic Risk in Children: The Sit Less for Health Cross-Sectional Study

BACKGROUND

The objective of this study was to investigate the associations between sedentary behavior patterns and cardiometabolic risk in children using a monitor that accurately distinguishes between different postures.

METHODS

In this cross-sectional study, 118 children (67 girls) aged 11-12 years had adiposity, blood pressure, lipids, and glucose measured, and then they wore an activPAL device to record sitting, standing, and stepping for 7 consecutive days. Data were analyzed using multiple linear regression.

RESULTS

After adjustment for potential confounders and moderate to vigorous physical activity, the number of breaks in sitting was significantly negatively associated with adiposity (standardized β ≥ -0.546; P ≤ .001) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.415; P ≤ .01). Time in prolonged sitting bouts was significantly negatively associated with adiposity (β ≥ -0.577; P ≤ .001) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.432; P ≤ .05). Standing time was significantly negatively associated with adiposity (β ≥ -0.270; P ≤ .05) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.312; P ≤ .05).

CONCLUSIONS

This study suggests that increasing the number of breaks in sitting and increasing standing time are beneficially associated with cardiometabolic risk and should be considered in health promotion interventions in children.