Prevalence of objectively measured sedentary behavior in early years: Systematic review and meta-analysis

Longitudinal relationship between organised and non-organised physical activities and overall physical activity in children aged 3-11 years

Young children's physical activity (PA) has been decreasing while their sports participation has been increasing. Therefore, the aim of this research was to longitudinally examine whether and, if so, how organised and non-organised PA participation by early childhood education and care (ECEC)-aged children (T1; 3-8 years) predicted their accelerometer-measured PA at primary school age (T2; 7-11 years). Secondarily, changes in organised and non-organised PA participation over time were investigated. The cluster-randomised study participants comprised 501 Finnish children (52.3% girls: T1, Mage = 5.57 ± 1.06; T2, Mage = 8.80 ± 1.07). PA participation was queried via guardian questionnaire at T1 and T2. Organised PA participation was operationalised as non-participation, participation in one sport or multisport (two or more) participation; non-organised PA was operationalised as time spent outdoors on weekdays and on weekend days. PA at T2 was measured using accelerometers. The primary outcome was tested using linear regressions, while a paired sample t-test and Mann-Whitney U test assessed differences between T1 and T2. The results showed outdoor time and organised sports participation increased from T1 to T2. Moreover, outdoor time at T1 predicted more moderate-to-vigorous PA (MVPA) and less sedentary time at T2, while multisport participation predicted significantly more MVPA and less sedentary time at T2. Overall, being outdoors and multisport participation at younger ages appear to have predicted Finnish children's later (MV) PA and sedentary behaviour.

Parent-Child Associations in Accelerometer-Measured Physical Activity and Sedentary Behaviour: The FAMIPASS Study

Parent-child patterns in objectively measured movement behaviours were the highlight of this study. A total of 381 families (337 mothers, 256 fathers, 190 daughters, and 191 sons) from 36 randomly selected schools and kindergartens provided valid accelerometer data. Sedentary behaviour and physical activity (PA) were assessed using ActiGraph accelerometers. Spearman's rho was used to evaluate parent-child associations, while logistic regression analysis (the backward LR method) was used to recognize factors related to children's achievement of PA recommendations. Results indicated that girls engaged more in light PA, while boys showed higher levels of moderate and vigorous PA. Mothers spent less time sitting and more time in light PA compared to fathers, resulting in higher total PA levels. Father-son pairs showed a stronger association in total PA than mother-son pairs. Children aged 6-10 years and those with mothers who engaged in more vigorous PA were more likely to meet PA recommendations compared to younger children and those with less active mothers.

Correlates of Toddlers' Physical Activity Levels and Sedentary Behavior During Unstructured Outdoor Play in Early Childhood Education and Daycare Settings

Despite recent research showing that early childhood education and daycare settings (ECEC) have an important role in promoting toddlers' physical activity (PA), crucial information gaps remain regarding toddlers' PA and sedentary behavior (SB) in these outdoor settings. We aimed in this study to: (a) analyze PA patterns and SB during unstructured outdoor play time in preschool and daycare environments using accelerometry and systematic observation; (b) provide concurrent accelerometry and observational data to help validate the Observational System for Recording Physical Activity in Children-Preschool Version (OSRAC-P); and (c) examine individual, social and environmental correlates of PA and SB during toddlers' unstructured outdoor play time. We found that: (a) toddlers displayed high amounts of PA with no sex, BMI, and/or age differences in PA and SB levels,; (b) environmental variables (e.g., fixed equipment and playground density) were not associated with PA levels or SB intensity; (c) the OSRAC-P was a reliable and valid means of observing and analyzing toddlers' PA patterns during unstructured outdoor play time; and (e) different social patterns between boys and girls did not impact PA levels or patterns. Combining different measurement methods permitted an improved understanding of unstructured outdoor play in preschool and daycare settings.

Cross-sectional and longitudinal associations between the 24-hour movement behaviours, including muscle and bone strengthening activity, with bone and lean mass from childhood to adolescence

BACKGROUND

This study aimed to assess whether moderate-to-vigorous physical activity (MVPA), sport and exercise as a proxy measure of muscle and bone strengthening activity, sedentary behaviour, and sleep were associated with total-body-less-head (TBLH) bone mineral content (BMC) and TBLH lean mass cross-sectionally and longitudinally from age 6 to 9 years and age 9 to 11 years to age 15 to 17 years.

METHODS

We used longitudinal data from a population sample of Finnish children from the Physical Activity and Nutrition in Children study (age 6 to 9 years: n = 478, 229 females; age 9 to 11 years: n = 384, 197 females; age 15 to 17 years: n = 222, 103 females). Linear regression analysed the cross-sectional and longitudinal associations between accelerometer-assessed MVPA, sedentary time and sleep, and questionnaire-assessed sport and exercise participation and screen time with dual-energy X-ray absorptiometry-assessed TBLH BMC and lean mass.

RESULTS

In females, MVPA at age 6 to 9 years was positively associated with TBLH BMC at age 15 to 17 years (β = 0.008, p = 0.010). Sport and exercise at age 9 to 11 years was positively associated with TBLH BMC (β = 0.020, p = 0.002) and lean mass (β = 0.343, p = 0.040) at age 15 to 17 years. MVPA at age 9 to 11 years was positively associated with TBLH lean mass (β = 0.272, p = 0.004) at age 15 to 17 years. In males, sleep at age 6 to 9 years was positively associated with TBLH lean mass (β = 0.382, p = 0.003) at age 15 to 17 years. Sport and exercise at age 9 to 11 years was positively associated with TBLH BMC (β = 0.027, p = 0.012) and lean mass (β = 0.721, p < 0.001) at age 15 to 17 years.

CONCLUSIONS

Promoting engagement in the 24-hour movement behaviours in childhood, particularly sport and exercise to strengthen muscle and bone, is important in supporting bone and lean mass development in adolescence.

TRIAL REGISTRATION

NCT01803776; first trial registration date: 04/03/2013.

Managing Screen Use in the Under-Fives: Recommendations for Parenting Intervention Development

The impact of excessive screen use on children's health and development is a public health concern and many countries have published recommendations to limit and guide the use of screen media in childhood. Despite this, international studies report that the majority of parents and children do not adhere to screen use recommendations. Existing research aiming to understand children' screen use has largely focused on older children, and on demographic and structural aspects of the child's environment. Parents play a central role in determining young children's screen use and identify numerous barriers to developing healthy screen use practices with their children. However, no clear models exist that incorporate key parenting factors in understanding children's screen use, which presents an impediment to intervention development. Likewise, while some evidence exists for interventions to improve children's screen use behaviours, most are focused on older children and parental involvement has generally been limited. In this paper, we overview key factors associated with screen use in young children (< 5 years) and summarise the existing evidence base for interventions designed to support healthy screen use. This paper proposes a conceptual model linking aspects of parenting and the socio-ecological environment to young children's screen use. Our proposed model could be used to design longitudinal studies of screen use predictors and outcomes, and inform intervention development. Finally, the paper provides key recommendations for future research, intervention development and testing.

Adherence to the World Health Organization's physical activity recommendation in preschool-aged children: a systematic review and meta-analysis of accelerometer studies

BACKGROUND

The World Health Organization (WHO) recommend that preschool-aged children should engage in 180 min of total physical activity (TPA) including 60 min of moderate-to-vigorous physical activity (MVPA) each day. No systematic reviews or meta-analyses have pooled adherence to the recommendation across multiple studies. This study aimed to estimate the prevalence of preschool-aged children achieving the WHO's physical activity recommendation for young children, and determine if the prevalence differed between boys and girls.

METHODS

Primary literature searches were conducted on six online databases and a machine learning assisted systematic review was used to identify relevant studies. Studies written in English reporting on the prevalence of children aged 3-5 years achieving overall WHO physical activity recommendation or the individual TPA or MVPA aspects of the recommendation measured using accelerometers were eligible for inclusion. Random effects meta-analysis was used to determine the prevalence of preschools achieving the overall WHO recommendation and the individual TPA and MVPA aspect of the recommendation, and to determine difference in prevalence between boys and girls.

RESULTS

Forty-eight studies reporting on 20,078 preschool-aged children met the inclusion criteria. Based on the most commonly employed accelerometer cut-points across all aspects of the recommendation, 60% (95% Confidence Interval [CI] = 37%, 79%) of preschool-aged children adhered to the overall physical activity recommendation, 78% (95% CI = 38%, 95%) adhered to the TPA aspect of the recommendation, and 90% (95% CI = 81%, 95%) adhered to the MVPA aspect of the recommendation. There was substantial variability is prevalence estimates between different accelerometer cut-points. Girls were significantly less likely to achieve the overall recommendation and the MVPA aspect of the recommendation than boys were.

CONCLUSIONS

Although there was substantial variability in estimated prevalence of preschool-aged children adhering the WHO physical activity recommendation between various accelerometer cut-points, the weight of available evidence suggests that the majority of young children are adhering to the overall recommendation and the individual TPA and MVPA aspects of the recommendation. Large-scale, intercontinental surveillance studies are needed to further strengthen the evidence regarding the prevalence of preschool-aged children achieving physical activity recommendation globally.

Muscle disuse as hindlimb unloading in early postnatal mice negatively impacts grip strength in adult mice: a pilot study

Physical inactivity has many detrimental effects on health, yet the impact of physical inactivity in early life on muscle health in adulthood remains unknown. Early postnatal malnutrition has prolonged effects into adulthood and we propose that early postnatal (P) physical inactivity would have similar negative effects. To test this hypothesis, we exposed postnatal mice (∼P28, C57BL/6J) to 14 days of physical inactivity (shortly after weaning, from ∼P28 to P42 days of age) in the form of muscle disuse with hindlimb unloading (HU). After this early-life physical inactivity, they were allowed to normally ambulate until 5 mo of age (P140, adulthood) when they underwent 14 days of HU with and without 7-day recovery. They were then tested for physical function (grip strength) and muscles were extracted and weighed. Immunofluorescence was carried out on these muscle cross sections for analysis of myofiber cross-sectional area (fCSA), macrophage density (CD68+ cells), and extracellular matrix (ECM) area. Muscle weights and fCSA and myofiber diameter were used to quantify changes in muscle and fiber size. Compared with age-matched controls, no notable effects of early-life physical inactivity (HU) on skeletal muscle and myofiber size were observed. However, a significant reduction in adult grip strength was observed in those exposed to HU early in life. This was associated with reduced muscle macrophages and increased ECM area. Exposure to a short period of early life disuse has negative enduring effects into adulthood impacting grip strength, muscle macrophages, and muscle composition as low muscle quality.NEW & NOTEWORTHY We demonstrate that early life disuse resulted in less grip strength in adulthood. Analysis of muscle composition demonstrated no loss of whole muscle or myofiber size indicating lower muscle quality akin to premature aging. This poor muscle quality was characterized by altered muscle macrophages and extracellular matrix area. We demonstrate intriguing correlations between this loss of grip strength and muscle macrophages and also area of noncontractile tissue in the muscle.

The association between sedentary behavioral characteristics and poor vision among Chinese children and adolescents

Introduction

To understand the features of sedentary behavior of Chinese children and adolescents and its relationship with poor visual acuity, a self-administered "Questionnaire on Sedentary Behavior of Children and Adolescents" was used to survey 4,203 students in grades 4-12 in six administrative regions of China.

Results

(1) The average time spent in sedentary behaviors (SB) of Chinese children and adolescents was about 8.1 h per day, of which the academic sedentary time was the longest, accounting for 79.2% of total sedentary time. The total time spent on SB and the time spent on studying SB were more in the upper grades and less in screen SB and cultural leisure SB, respectively. There were significant sex differences in total SB time (p < 0.05) and weekend sedentary behaviors time (SB-WD) (p < 0.01) among Chinese children and adolescents, with girls being more likely to be higher than boys. There were also significant differences in sedentary time across different regions (p < 0.05), and the longest total sedentary time in East China. (2) Reduction parents' sedentary time and limitation of sedentary behaviors and the use of electronics among children and adolescents can effectively reduce sedentary time among Chinese children and adolescents. (3) Sedentary time was significantly higher in children and adolescents with poor vision than in those with normal vision (p < 0.01), and study SB and screen SB were important independent factors affecting vision. (4) Timing of breaks in SB can play a positive role in promoting vision health.

Conclusion

There were significant grade, sex, and regional differences in the SB of Chinese children and adolescents, and sedentary time was strongly related to the prevalence of poor vision detection rate.

Home- and Community-Based Interventions for Physical Activity and Early Child Development: A Systematic Review of Effective Strategies

This systematic review examined the effects of home/family and community-based interventions on physical activity (PA) and developmental outcomes in early childhood. A search strategy was employed using four electronic databases (Academic Search Complete, CINAHL Complete, MEDLINE, and SPORTDiscus). Interventions investigating weight status (i.e., BMI), physical activity, sedentary behavior, and/or motor proficiency that took place in home, family, or community settings were assessed. Studies were eligible if they were peer-reviewed, available in English, published between 2011 and 2021, and if samples consisted of healthy young children (2-5 years old). There were 24 studies retained (8351 participants) spanning from the United States (n = 12), Australia (n = 3), Canada (n = 2), Switzerland (n = 2), Finland (n = 2), Netherlands (n = 1), and other Eastern European countries (n = 2). There were 19 studies that incorporated home/family-based approaches and 14 studies that incorporated community-based approaches. Studies ranged in intervention duration from 6 weeks to 24 months. It suggests that improving PA participation in young children was especially challenging to solicit improvement (only 25% of all studies found significant improvement in PA after intervention). Distributing educational material to parents/families, consistent, direct contact with parents, and encouraging community engagement were identified as effective strategies to promote physical activity, healthy weight status, and motor skills in young children.

Correlates of sedentary behavior in Asian preschool-aged children: A systematic review

This systematic review aims to identify the multilevel correlates of sedentary behavior (SB) and its sub-domains among preschool-aged children aged 0-7 years in Asia. We systematically searched for studies published from 2000 onwards using terms related to SB correlates and Asia in six databases. Eligible studies were observational and used quantitative methods to examine correlates of total, and domain-specific SB (screen viewing [SV] and non-screen-based SB) in Asian children living in Asia. Two reviewers independently screened identified references. Following quality assessment of included studies, we performed narrative synthesis to summarize the evidence on the intrapersonal, interpersonal, environmental correlates of total and domain-specific SB (PROSPERO: CRD42018095268). Twenty-two studies from 4 regions and 12 countries/territories were included. Out of the 94 correlates explored, the following associations were consistent: older age, being a boy, non-Chinese ethnicity (Southeast Asia), younger maternal age, higher maternal and paternal television-viewing time with higher SV; higher SV at earlier age with higher SV and total SB; and presence of TV/computer in the bedroom with higher leisure-time SB. We encourage more studies from low- and middle-income Asian countries with an increased focus on different SB domains, further exploration of environmental correlates, and the use of objective measurements to capture SB.

Levels and Correlates of Objectively Measured Sedentary Behavior in Young Children: SUNRISE Study Results from 19 Countries

PURPOSE

There is a paucity of global data on sedentary behavior during early childhood. The purpose of this study was to examine how device-measured sedentary behavior in young children differed across geographically, economically, and sociodemographically diverse populations, in an international sample.

METHODS

This multinational, cross-sectional study included data from 1071 children 3-5 yr old from 19 countries, collected between 2018 and 2020 (pre-COVID). Sedentary behavior was measured for three consecutive days using activPAL accelerometers. Sedentary time, sedentary fragmentation, and seated transport duration were calculated. Linear mixed models were used to examine the differences in sedentary behavior variables between sex, country-level income groups, urban/rural settings, and population density.

RESULTS

Children spent 56% (7.4 h) of their waking time sedentary. The longest average bout duration was 81.1 ± 45.4 min, and an average of 61.1 ± 50.1 min·d-1 was spent in seated transport. Children from upper-middle-income and high-income countries spent a greater proportion of the day sedentary, accrued more sedentary bouts, had shorter breaks between sedentary bouts, and spent significantly more time in seated transport, compared with children from low-income and lower-middle-income countries. Sex and urban/rural residential setting were not associated with any outcomes. Higher population density was associated with several higher sedentary behavior measures.

CONCLUSIONS

These data advance our understanding of young children's sedentary behavior patterns globally. Country income levels and population density appear to be stronger drivers of the observed differences, than sex or rural/urban residential setting.

Classroom Teacher Efficacy Toward Implementation of Physical Activity in the D-SHINES Intervention

BACKGROUND

Given levels of sedentary behavior among youth, teachers have been called upon to increase physical activity (PA) by implementing classroom PA breaks. School-based interventions enacted in classroom settings have shown promise in increasing youth PA. Yet little is known about how teacher efficacy toward implementing classroom PA breaks may influence intervention effects.

PURPOSE

Therefore, the purpose of this study was to examine how the Dearborn School Health through Integrated Nutrition and Exercise Strategies (D-SHINES) intervention, implemented across 8 schools, influenced classroom teacher's efficacy toward providing classroom PA breaks.

METHODS

A mixed-methods design examined classroom teachers' efficacy toward implementing classroom PA breaks and used semi-structured interviews to better understand teachers' efficacy and implementation.

RESULTS

Quantitative results indicated that teacher efficacy significantly increased over the intervention period and that general and institutional efficacy predicted higher amounts of PA breaks offered. Qualitative results suggested that to enhance teachers' facilitation of classroom PA breaks, one must tap into the institutional, student, and educational factors that constitute teacher efficacy.

IMPLICATIONS FOR SCHOOL HEALTH

Designing interventions that focus on teacher efficacy toward classroom PA may be a viable way to increase PA breaks in schools. Implications for the whole school, whole community, whole child model are discussed.

Objectively Measured Physical Activity and Sedentary Time of Suburban Toddlers Aged 12-36 Months

Low levels of physical activity may predispose children to the development of obesity and related chronic diseases in later life. The aims of this study were as follows: (1) quantitatively describe the levels of habitual physical activity in a contemporary sample of suburban children aged 12 to 36 months; (2) assess for gender differences in physical activity and sedentary behavior; (3) examine the specific effects of ethnicity, gender and overweight status on the objectively measured physical activity; and (4) quantify the tracking of physical activity in a subset of children over 1 year. During year one, 142 participants wore the GT3X Actigraph for 3 days. At a 1-year follow-up, a subset of 25 participants wore the Actigraph for 7 consecutive days. GLM and t-tests as appropriate were carried out to assess the influence of gender on the physical activity level. Spearman rank correlations, percentage agreement and kappa statistics assessed the tracking of physical activity. The results showed no significant gender differences in any anthropometric measurements, sedentary behavior or MVPA (p > 0.05). There were also no significant gender, ethnicity or overweight interaction for sedentary behavior, time spent in light PA and time spent in MVPA (p > 0.05). For tracking, there was a moderate strength of agreement for MVPA. Considering the disproportionate effects of obesity in minority groups, culturally appropriate interventions targeting the reduction in sedentary behavior are urgently required.

Parent-perceived neighbourhood environment, parenting practices and preschool-aged children physical activity and screen time: a cross-sectional study of two culturally and geographically diverse cities

BACKGROUND

Preschool-aged children's physical activity (PA) and screen time (ST) are important health-related behaviours likely influenced by PA opportunities, parental perceptions of neighbourhood safety and parenting practices pertaining to PA and ST. How these factors interact to impact on young children's PA and ST, and whether their effects are generalisable across cultures and geographical location is not known. This study addressed these knowledge gaps by conducting pooled analyses of comparable data from two culturally and geographically diverse samples - Chinese parent-child dyads from an ultra-dense city (Hong Kong, China) and Latino parent-child dyads from a low-density city (Houston, USA).

METHODS

The analytical sample consisted of 164 Hong Kong Chinese and 84 US Latino parent-child dyads with data on socio-demographic characteristics, parent-perceived neighbourhood destinations and facilities for children's PA, physical and social safety-related neighbourhood attributes, PA-related parenting practices and child's ST and accelerometer-assessed PA. Generalised linear models with robust standard errors accounting for neighbourhood-level clustering were used to estimate associations and interaction effects.

RESULTS

Hong Kong Chinese children accumulated less PA than US Latino children, although the latter had more ST. Hong Kong Chinese parents reported more parenting practices promoting inactivity. Neighbourhood PA opportunities were positively related to children's PA only if parental perceptions of neighbourhood safety were favourable, and the associations of physical neighbourhood environment characteristics with children's PA and ST depended on PA-related parenting practices. Community cohesion was positively related to children's PA and negatively related to ST, while parental promotion of ST was positively associated with children's ST. Correlates of children's PA and ST did not differ by city.

CONCLUSIONS

The substantial differences in activity patterns between Hong Kong Chinese and US Latino preschool-aged children observed in this study are likely due to a combination of cultural and built environmental factors. However, the fact that no between-city differences in correlates of PA and ST were detected indicates that both populations of children are equally affected by parent-perceived neighbourhood environmental characteristics and parenting practices. Overall, this study highlights the importance of considering how various individual-, home- and neighbourhood physical and social factors interact to influence young children's health-promoting activity levels.

Association between sedentary behavior and low back pain; A systematic review and meta-analysis

Background: Sedentariness is a substantial risk for many chronic diseases. We aimed to investigate the correlation of sedentary behavior and its indicators with low back pain (LBP) among adults and children.

Methods: Original articles published up to April 28, 2020, using PubMed, Embase, Web of Science and Scopus were evaluated. Odds ratio (OR, 95% CI) was considered the overall effect size for desired associations.

Results: We reviewed 49 English articles with analytical observational study design, of which, 27 studies with cross sectional/survey design were retained in the meta-analysis. Among adults, sedentary lifestyle was a considerable risk factor for LBP (OR=1.24, 1.02-1.5); prolonged sitting time (OR=1.42, 1.09-1.85) and driving time (OR=2.03, 1.22-3.36) were the significant risk factors. Sedentary behavior was associated with LBP in office workers (OR=1.23). Moreover, excess weight (OR=1.35, 1.14-1.59) and smoking (OR=1.28, 1.03-1.60) were associated with LBP. Among children, sedentary lifestyle was a remarkable risk factor for LBP (OR=1.41, 1.24- 1.60); prolonged TV watching (OR=1.23, 1.08-1.41) and computer/mobile using and console playing time (OR=1.63, 1.36-1.95) were significant risk factors for LBP. Consumption of coffee, however, has yield conflicting results to be considered as a risk factor. Moreover, the researches on the correlation between sedentariness and high-intensity LBP are scarce and inconclusive.

Conclusion: Sedentary behavior, whether in work or leisure time, associates with a moderate increase in the risk of LBP in adults, children and adolescents.

A systematic review of the validity, reliability, and feasibility of measurement tools used to assess the physical activity and sedentary behaviour of pre-school aged children

Physical activity (PA) and sedentary behaviour (SB) of pre-school aged children are associated with important health and developmental outcomes. Accurate measurement of these behaviours in young children is critical for research and practice in this area. The aim of this review was to examine the validity, reliability, and feasibility of measurement tools used to assess PA and SB of pre-school aged children.Searches of electronic databases, and manual searching, were conducted to identify articles that examined the measurement properties (validity, reliability or feasibility) of measurement tools used to examine PA and/or SB of pre-school aged children (3-7 years old). Following screening, data were extracted and risk of bias assessment completed on all included articles.A total of 69 articles, describing 75 individual studies were included. Studies assessed measurement tools for PA (n = 27), SB (n = 5), and both PA and SB (n = 43). Outcome measures of PA and SB differed between studies (e.g. moderate to vigorous activity, step count, posture allocation). Most studies examined the measurement properties of one measurement tool only (n = 65). Measurement tools examined included: calorimetry, direct observation, combined heart rate and accelerometry, heart rate monitors, accelerometers, pedometers, and proxy report (parent, carer or teacher reported) measures (questionnaires or diaries). Studies most frequently assessed the validity (criterion and convergent) (n = 65), face and content validity (n = 2), test-retest reliability (n = 10) and intra-instrument reliability (n = 1) of the measurement tools. Feasibility data was abstracted from 41 studies.Multiple measurement tools used to measure PA and SB in pre-school aged children showed some degree of validity, reliability and feasibility, but often for different purposes. Accelerometers, including the Actigraph (in particular GT3X versions), Actical, ActivPAL and Fitbit (Flex and Zip), and proxy reported measurement tools used in combination may be useful for a range of outcome measures, to measure intensity alongside contextual information.

Longitudinal differences in levels and bouts of sedentary time by different day types among Australian toddlers and pre-schoolers

The aim of the present study was to characterize sedentary time (ST) and sedentary bouts among young children, across a typical week and by day type (childcare days, non-childcare days and weekends), over a 12-month period.ST % (ST/accelerometer wear time*100) and number of sedentary bouts/hours were assessed using accelerometers at two time-points 12-months apart in 153 toddlers and 74 pre-schoolers. Differences between baseline and follow-up according to the whole week and the different day types were calculated using linear mixed models with adjustment for age, sex, socio-economic status and zBMI.During the weekend, toddlers had more 20-30 min/h sedentary bouts at follow-up than at baseline (MD: 0.03). In pre-schoolers, ST % (MD:-8.4), the number of 1-4 min/h (MD:-1.45), 5-9 min/h (MD: -0.46) and 10-19 min/h sedentary bouts (MD:-0.11) were lower at baseline, compared to follow-up, on non-childcare days; as were the number of 5-9 min/h sedentary bouts on weekends (MD:0.40). P < 0.05 for all.This study found that longer sedentary bouts (20-30 min/h) tended to decrease among toddlers and pre-schoolers, whereas ST and shorter sedentary bouts increased over 12-months, particularly among pre-schoolers on non-childcare weekdays. Non-childcare days, and home environment may be targeted for intervention to reduce ST and sedentary bouts among pre-schoolers.

Weekday-Weekend Sedentary Behavior and Recreational Screen Time Patterns in Families with Preschoolers, Schoolchildren, and Adolescents: Cross-Sectional Three Cohort Study

Background: Excessive recreational screen time (RST) has been associated with negative health consequences already being apparent in preschoolers. Therefore, the aim of this study was to reveal parent-child sedentary behavior, and RST patterns and associations with respect to the gender, age category of children, and days of the week. Methods: Our cross-sectional survey included 1175 parent-child dyads with proxy-reported RST data collected during a regular school week during the spring and fall between 2013 and 2019. The parent-child RST (age and RST) relationship was quantified using Pearson’s (r_P) correlation coefficient. Results: Weekends were characterized by longer RST for all family members (daughters/sons: +34/+33 min/day, mothers/fathers: +43/+14 min/day) and closer parent-child RST associations than on weekdays. The increasing age of children was positively associated with an increase in RST on weekdays (+6.4/+7.2 min per year of age of the daughter/son) and weekends (+5.8/+7.5 min per year of age of the daughter/son). Conclusions: Weekends provide a suitable target for implementation of programs aimed at reducing excessive RST involving not only children, but preferably parent-child dyads.

Objectively Measured Sedentary Levels and Bouts by Day Type in Australian Young Children

BACKGROUND

This study aimed to understand whether a higher number of sedentary bouts (SED bouts) and higher levels of sedentary time (SED time) occur according to different day types (childcare days, nonchildcare weekdays, and weekends) in Australian toddlers (1-2.99 y) and preschoolers (3-5.99 y).

METHODS

The SED time and bouts were assessed using ActiGraph GT3X+ accelerometers. The sample was composed of 264 toddlers and 343 preschoolers. The SED bouts and time differences were calculated using linear mixed models.

RESULTS

The toddlers' percentage of SED time was higher on nonchildcare days compared with childcare days (mean difference [MD] = 2.3; 95% confidence interval, 0.7 to 3.9). The toddlers had a higher number of 1- to 4-minute SED bouts on nonchildcare days compared with childcare days. The preschoolers presented higher percentages of SED time during nonchildcare days (MD = 3.1; 95% confidence interval, 1.6 to 4.5) and weekends (MD = 1.9; 95% confidence interval, 0.4 to 3.4) compared with childcare days. The preschoolers presented a higher number of SED bouts (1-4, 5-9, 10-19, and 20-30 min) during nonchildcare days and weekends compared with childcare days. No SED times or bout differences were found between nonchildcare days and weekends, neither SED bouts >30 minutes on toddlers nor on preschoolers.

CONCLUSION

The SED time and bouts seem to be lower during childcare periods, which means that interventions to reduce sedentary time should consider targeting nonchildcare days and weekends.

Psychological Correlates of Sedentary Screen Time Behaviour Among Children and Adolescents: a Narrative Review

PURPOSE OF REVIEW

The aims of this narrative review were to (1) synthesise the literature on the relationship between screen time and important mental health outcomes and (2) examine the underpinning factors that can influence this association.

RECENT FINDINGS

Paralleling the rise of mental health issues in children and adolescents is the ubiquitous overuse of screens, but it is unclear how screen time is related to important mental health outcomes and whether this association differs by gender, age and screen type.

METHODS

Medline/PubMed, PsychINFO and Google Scholar databases were searched on December 2019 for articles published mainly in the last 5 years. The search focused on two main concepts: (i) screen time and (ii) mental health outcomes including anxiety, depression, psychological and psychosocial well-being and body image concerns.

RESULTS

Sixty studies were included in the review. Higher levels of screen time were associated with more severe depressive symptoms. We found moderate evidence for an association between screen time and poor psychological well-being and body dissatisfaction especially among females. Relationships between screen time and anxiety were inconsistent and somewhat gender specific. Social media use was consistently associated with poorer mental health. Higher levels of screen time are generally associated with poorer mental health outcomes, but associations are influenced by screen type, gender and age. Practitioners, parents, policy makers and researchers should collectively identify and evaluate strategies to reduce screen time, or to use screens more adaptively, as a means of promoting better mental health among children and adolescents.

Associations between daily ambient temperature and sedentary time among children 4-6 years old in Mexico City

BACKGROUND

Sedentary behavior is a worldwide public health concern. There is consistent and growing evidence linking sedentary behavior to mortality and morbidity. Early monitoring and assessment of environmental factors associated with sedentary behaviors at a young age are important initial steps for understanding children's sedentary time and identifying pertinent interventions.

OBJECTIVE

This study examines the association between daily temperature (maximum, mean, minimum, and diurnal variation) and all-day sedentary time among 4-6 year old children in Mexico City (n = 559) from the year 2013 to 2015.

METHODS

We developed a spatiotemporally resolved hybrid satellite-based land use regression temperature model and calculated percent daily sedentary time from aggregating 10-second epoch vertical counts captured by accelerometers that participants wore for one week. We modeled generalized additive models (GAMs), one for each temperature type as a covariate (maximum, mean, minimum, and diurnal variation). All GAMs included percent all-day sedentary time as the outcome and participant-level random intercepts to account for repeated measures of sedentary time. Our models were adjusted for demographic factors and environmental exposures.

RESULTS

Daily maximum temperature, mean temperature, and diurnal variation have significant negative linear relationships with all-day sedentary time (p<0.01). There is no significant association between daily minimum temperature and all-day sedentary time. Children have on average 0.26% less daily sedentary time (approximately 2.2 minutes) for each 1°C increase in ambient maximum temperature (range 7.1-30.2°C), 0.27% less daily sedentary time (approximately 2.3 minutes) for each 1°C increase in ambient mean temperature (range 4.3-22.2°C), and 0.23% less daily sedentary time (approximately 2.0 minutes) for each 1°C increase in diurnal variation (range 3.0-21.6°C).

CONCLUSIONS

These results are contrary to our hypothesis in which we expected a curvilinear relationship between temperature (maximum, mean, minimum, and diurnal variation) and sedentary time. Our findings suggest that temperature is an important environmental factor that influences children's sedentary behavior.

How Many Days are Necessary to Represent Typical Daily Leg Movement Behavior for Infants at Risk of Developmental Disabilities?

BACKGROUND

Movement characteristics can differentiate between infants at risk and infants with typical development. However, it is unknown how many days are needed to accurately represent typical daily behavior for infants at risk of developmental disabilities when using wearable sensors. To consider the balance between participant burden and the amount of data collected and optimizing the efficiency of data collection, our study determined (1) how many days were necessary to represent typical movement behavior for infants at risk of developmental disabilities and (2) whether movement behavior was different on weekend days and weekdays.

METHODS

We used Opal wearable sensors to collect at least 5 days of 11 infants' leg movement data. The standard (average of 5 days) was compared with four methods (average of the first 1/2/3/4 days) using the Bland-Altman plots and the Spearman correlation coefficient. We also compared the data from the average of 2 weekend days to the average of the first 2 weekdays for 8 infants.

RESULTS

The Spearman correlation coefficient comparing the average of the first 2 days of data and the standards were all above 0.7. The absolute differences between them were all below 10% of the standards. The Bland-Altman plots showed more than 90% of the data points comparing the average of 2 days and the standards fell into the limit of agreement for each variable. The absolute difference between weekend days and weekdays for the leg movement rate, duration, average acceleration, and peak acceleration was 15.2%, 1.7%, 6.8% and 6.3% of the corresponding standard, respectively.

CONCLUSION

Our results suggest 2 days is the optimal amount of data to represent typical daily leg movement behavior of infants at risk of developmental disabilities while minimizing participant burden. Further, leg movement behavior did not differ distinctly across weekend days and weekdays. These results provide supportive evidence for an efficient amount of data collections when using wearable sensors to evaluate movement behavior in infants at risk of developmental disabilities.

Sedentary time and blood pressure in Australian toddlers: The get-up study longitudinal results

Epidemiological data suggests that the genesis of cardiovascular disease occurs during childhood. Sedentary time (ST) is a main driver of high blood pressure (BP) in adolescents and adults. However, associations between ST and cardiovascular health in young children are uncertain. Prospective associations between ST and BP were assessed among 172 toddlers (88 boys), aged 19.5 ± 3.9 months at baseline, recruited from the GET-UP! Study, Australia and followed over a 12-month period. BP was measured with a digital monitor and z-scores were computed by age and sex for systolic and diastolic BP. Total ST was measured over 7 days using Actigraph accelerometers and expressed over a 24-h period. Multilevel linear regression models were used to assess regression coefficients and standard errors, predicting BP at follow-up from ST at baseline. Analyses controlled for socio-economic status, height, age, gender, group (intervention or control) and zWC at baseline. Adjusted analyses showed that total ST did not predict systolic or diastolic BP (β = 0.0009, p = 0.368 and β = 0.002, p = 0.05, respectively). Most likely, longer follow-up periods might be needed to confirm or rule out our results, as the effects of cumulative ST over time on BP values are prone to manifest later in life and track into adolescence and adulthood.

Gender differences in barriers to physical activity among adolescents

BACKGROUND AND AIMS

Great attention is now being paid to effective policies and programs to promote physical activity among adolescents, girls consistently found to be less active than boys. The aim of this study was to assess gender differences in perceived barriers for physical activity practice and their relationship with physical activity levels and physical condition among adolescents.

METHODS AND RESULTS

A cross-sectional study was conducted in February-April 2017 among students (n = 368) in the last year of two state high schools in Florence (Italy). Participants underwent the measurements of anthropometric parameters (height, weight, waist, and hip circumferences), blood pressure and administration of 3 standardized questionnaires (International Physical Activity Questionnaire, Mediterranean Diet Score Quiz, and Barriers to Being Active Quiz). Gender differences were assessed using a multivariate logistic regression model (adjusted for age and body mass index). The prevalence of participants who reached recommended levels was lower among girls compared to boys (OR 0.27; 95% CI 0.17-0.43). The number of perceived barriers to physical activity was higher among girls than among boys (OR 1.52; 95% CI 1.29-1.79), lack of energy for exercise and lack of willpower being the two barriers most frequently reported by girls. At multivariable adjusted logistic regression analysis, gender (female), and positivity of at least one perceived barrier (score ≥ 5) were independently selected as the main determinants of non-compliance with WHO criteria for physical activity.

CONCLUSIONS

Exercise professionals should be aware of the barriers that young girls can face during exercise prescription and be able to contrast them with useful individual strategies.

The Get-Up! study: adiposity and blood pressure in Australian toddlers

BACKGROUND

Because the elevated blood pressure (BP) in childhood is strongly associated with overweight and is a risk factor for later cardiovascular disease, a need to comprehend the early development of BP and its association with overweight is needed. We assessed differences of BP by weight status in Australian toddlers.

METHODS

From the Get-Up! Study in Australia, this sample included 265 toddlers (136 boys), aged 19.6 ± 4.2 months. BP was measured with a digital vital signs monitor. Participants were categorized as nonoverweight and overweight according to the World Health Organization definition for body mass index (BMI). Physical activity was captured with activPAL accelerometers, during childcare hours. To test differences in BP between nonoverweight and overweight children, we performed an analysis of covariance adjusting for sex, age, physical activity, and socioeconomic status.

RESULTS

Children with overweight showed higher z systolic BP values (P = .042 for BMI and P = .023 for waist circumference) when compared to nonoverweight children. However, no differences were found for z diastolic BP levels, between overweight and nonoverweight children. After adjustments for potential confounders (socioeconomic status, physical activity, sex, and age), there were no significant differences in BP variables between BMI and waist circumference groups.

CONCLUSIONS

No associations between adiposity and BP levels were found in this sample. The unadjusted results, however, showed that children with higher levels of adiposity (BMI and waist circumference) exhibited higher levels of BP. Additional research is needed to determine which environmental and genetic factors might contribute to pediatric hypertension, particularly among toddlers.

Correlates of sedentary time in young children: A systematic review

Background: Young children appear to spend large portions of their waking time being sedentary. Understanding the correlates of sedentary time would assist in developing effective interventions among young children. The purpose of this systematic review was to summarize the current literature on the correlates of objectively measured sedentary time in young children aged 1-5.99y. Methods: This review was registered with PROSPERO (registration no. CRD42017081374) and aligned with the PRISMA Statement for systematic reviews. Five electronic databases (MEDline, CINAHL Complete, PsycINFO, SportDiscus, Scopus) were searched up to October 26, 2017 for studies investigating correlates of sedentary time measured using objective devices. A semiquantitative approach was used to synthesize data. Results: Forty-five studies were retrieved comprising 13,430 participants, and 84 correlates of sedentary time in young children were evaluated. The associations between sex, sleep habits, daily patterns (childcare vs. non-childcare hours), childcare type and sedentary time were indeterminate. Thirty-nine correlates were consistently unrelated. Forty-one potential correlates were examined in too few studies (<4) to make confident conclusions. Parental sedentary behaviour was reported 3 times and maternal sedentary behaviour was reported once. Out of these four studies, three were positively associated with child sedentary time. Conclusions: Despite reviewing 45 studies that evaluated associations for 84 correlates, this review was unable to identify any consistent correlates of sedentary time in young children. Additional research is needed in this area to provide robust evidence of the correlates of sedentary time in young children, particularly for those examined in only a small number of studies.

Individual-, home- and preschool-level correlates of preschool children's sedentary time

BACKGROUND

Prechoolers' significant portions of sedentary time (ST) is a public-health concern due to its high prevalence and negative health consequences. However, few studies have explored correlates of preschoolers' ST covering individual-, home- and preschool- factors within one study. The aim of this study was to identify the associations between multiple individual-, home- and preschool-level factors and preschoolers' ST. In addition, it was studied how much individual-, home- and preschool-level factors explained the variance in children's ST.

METHODS

A total of 864 children aged three to six, their parents and 66 preschools participated in the cross-sectional DAGIS study, which occurred between 2015 and 2016. The children wore an accelerometer for 1 week. Guardians, principals and early educators completed questionnaires covering the potential correlates of children's ST, for example, temperament, practices, self-efficacy and regulations. Multilevel regression analyses were conducted in multiple steps; calculation of marginal and conditional R² values occurred in the final phase.

RESULTS

Of the 29 studied correlates, the following factors remained significant in the final models. Being a boy (p < 0.001) and having high levels of surgency temperament (p < 0.001) were associated with lower ST. Regarding the home setting, frequent co-visits in physical activity (PA) places (p = 0.014) were associated with lower ST. Higher parental perceived barriers related to children's outside PA (p = 0.032) was associated with higher ST. None of the preschool setting factors remained significant in the final model. Approximately 11% of the variance in children's ST was attributed to factors related to the individual level whereas 5% was attributed to home-level factors; and 2% to preschool-level factors.

CONCLUSIONS

This study identified a set of correlates of preschool children's ST. Interventions aimed at reducing children's ST should develop strategies targeting established correlates of preschoolers' ST covering individual-, home- and preschool-level factors. The preschool-level factors included in this study explained little the variance in children's ST. However, the included measures may not have captured the essential preschool-level factors that specifically influence children's ST. Therefore, more studies are needed regarding potential preschool-level factors.

Infants' and toddlers' physical activity and sedentary time as measured by accelerometry: a systematic review and meta-analysis

BACKGROUND

Early experiences in physical activity (PA) are important to shape healthy movement behaviours long-term; as such, it is critical that PA is promoted from infancy, and that detrimental behaviours (e.g., prolonged sedentary time [ST]) are minimized. The purpose of this systematic review and meta-analysis was to examine infants' and toddlers' movement behaviours across daytime hours.

METHODS

Seven online databases were searched for terms related to infants (< 12 months), toddlers (12-35.9 months), PA, ST, and accelerometry. Two independent reviewers examined 4873 articles for peer-reviewed original research, published in English, that assessed infants' (counts/min) and/or toddlers' PA or ST (min/day) using accelerometry across daytime hours. Infants' mean PA level (counts/min) was averaged across studies, and ranges were produced. Estimates of toddlers' movement behaviours were aggregated meta-analytically to produce average daily rates, and accelerometer placement, cut-point validity, device type, and epoch length were tested as a moderating variables.

RESULTS

Twenty-four studies from 16 countries (published 2011-2019), representing 3699 participants, were included in the systematic review. Five studies reported on infants' PA, which ranged from 78.2 to 2580.5 cpm. Across 20 studies, toddlers' total PA, light PA, moderate-to vigorous-intensity PA, and ST ranged from 72.9 to 636.5, 48.5 to 582.4, 6.5 to 89.9, and 172.7 to 545.0 min/day, respectively. After taking into account accelerometer placement, cut-point validity, device type, and epoch length, we found that toddlers engaged in 246.19 min/day (SE = 28.50; 95% CI: 190.34, 302.04) of total PA, 194.10 min/day (SE = 28.76; 95% CI: 137.73, 250.47) of light PA, and 60.16 min/day (SE = 5.88; 95% CI: 48.64, 71.69) of moderate-to vigorous-intensity PA. Toddlers engaged in 337.04 min/day (SE = 32.67; 95% CI: 273.01, 401.07) of ST.

CONCLUSIONS

With limited studies conducted in infants (n = 5), PA estimates are inconclusive and largely heterogeneous. Overall, toddlers tend to exceed the total PA recommendation of 180 min/day; however, very little of this time is spent at higher movement intensities. Even with high PA rates, toddlers still engage in substantial ST. More consistent and valid measurement protocols are needed to improve comparability across studies.

Objectively-measured sedentary time and physical activity in a bi-ethnic sample of young children: variation by socio-demographic, temporal and perinatal factors

Background

Evidence suggests that South Asian school-aged children and adults are less active compared to the white British population. It is unknown if this generalises to young children. We aimed to describe variability in levels of physical activity and sedentary time in a bi-ethnic sample of young children from a deprived location.

Methods

This observational study included 202 South Asian and 140 white British children aged 1.5 to 5y, who provided 3181 valid days of triaxial accelerometry (Actigraph GT3X+). Variability in sedentary time and physical activity levels were analysed by linear multilevel modelling. Logistic multilevel regression was used to identify factors associated with physical inactivity (failing to perform ≥180 min of total physical activity including ≥60 min moderate-to-vigorous physical activity (MVPA) per day).

Results

There were no significant ethnic differences in the overall levels of behaviours; South Asian and white British children spent half of daily time sedentary, just over 40% in light physical activity, and the remaining 7.5 to 8% of time in MVPA. Sedentary time was lower and physical activity levels were higher in older children, and levels of MVPA and vector magnitude counts per minute (CPM) were higher on weekends compared to weekdays. In South Asian children, sedentary time was lower on weekends. Sedentary time was lower and physical activity levels were higher in spring compared to winter in white British children, and in all seasons compared to winter in South Asian children. South Asian children born at high birth weight performed more MVPA, and in both ethnicities there was some evidence that children with older mothers were more sedentary and less active. Sedentary time was higher and light physical activity was lower in South Asian children in the highest compared to the lowest income families. South Asian girls performed less MVPA, registered fewer vector magnitude CPM, and were 3.5 times more likely to be physically inactive than South Asian boys.

Conclusions

Sedentary time and physical activity levels vary by socio-demographic, temporal and perinatal characteristics in young children from a deprived location. South Asian girls have the most to gain from efforts to increase physical activity levels.

Trial registration

The Pre-schoolers in the Playground (PiP) pilot randomized controlled trial is registered with the ISRCTN (ISRCTN54165860; http://www.isrctn.com).

Preschool group practices and preschool children's sedentary time: a cross-sectional study in Finland

OBJECTIVES

Preschool is an important setting for regulating sedentary time (ST). The preschool day in Finland follows daily structures by having morning and afternoon slots for group-based activities that can encourage children for movement (eg, free play and outdoor time) or be still (eg, teacher-led sessions and sitting-based circles). This study aims to explore if the weekly routines in preschool and if more frequent visits in places encouraging physical activity (PA) are associated with children's ST during preschool hours.

DESIGN

Cross-sectional DAGIS (Increased Health and Wellbeing in Preschools) study in the years 2015 and 2016.

SETTING

In Finland.

PARTICIPANTS

864 children (48% girls, 4.7 years) from 159 preschool groups in 66 preschools OUTCOME MEASURES: A total of 778 children wore required lengths of time (at least 240 min per preschool day, at least 2 days) the accelerometer during preschool hours. Each preschool group reported their weekly schedule during the week, and one early educator completed a questionnaire covering practices. The following five measures related to weekly structures were formed; times of outdoors (times per day), teacher-led sessions (times per day), free play (low, middle or high), organised PA lessons (no lessons at all/others) and mixed activities (no lessons at all/others), and the following five measures about the frequencies of visits in places encouraging PA; nature trips (times per week), play parks (times per week), neighbourhood sport facilities (no visits at all/others), visits to gym or other indoor facility (no visits at all/others) and field trips to neighbourhoods (times per week). Multilevel linear regression analyses were conducted to measure the associations.

RESULTS

Of all the tested associations, only more frequently conducted nature trips were associated with lower children's ST during preschool hours (β=-1.026; 95% CI -1.804 to -0.248).

CONCLUSION

Frequent nature trips in preschools may be important due to its association with lower preschool children's ST.

The Impact of Shorter, More Frequent Outdoor Play Periods on Preschoolers' Physical Activity during Childcare: A Cluster Randomized Controlled Trial

Children's physical activity levels are higher at the start of outdoor playtime, which suggests that shorter, more frequent play periods might result in greater amounts of daily physical activity. In this extension of the Supporting Physical Activity in the Childcare Environment (SPACE) cluster randomized controlled trial, we explored the impact of four 30-min daily outdoor unstructured play periods on preschoolers' moderate-to-vigorous-intensity physical activity (MVPA). Experimental childcare centres (n = 6) implemented four 30-min daily outdoor playtimes for 8 weeks, while control centres (n = 6) maintained their two 60-min outdoor sessions. Actical™ accelerometers were used to measure preschoolers' physical activity pre- and post-intervention for 5 days during childcare hours. Linear mixed effects models were used to determine the impact of the intervention on preschoolers' MVPA. Of the 185 preschoolers enrolled (54.20% female; mean age = 39.90 months, SD = 7.24), 127 (65 experimental and 62 control) were included in the analysis (30% and 9% loss to follow-up for experimental and control group preschoolers, respectively). No significant differences in MVPA were observed between groups over time (p = 0.36). Preschoolers' MVPA did not improve after the introduction of shorter outdoor play periods. The loss of data due to wear time noncompliance and participant attrition may have influenced these findings. Trial registration: ISRCTN70604107 (October 8, 2014).