Monitoring of Physical Activity in Young Children: How Much Is Enough?

Higher consumption of ultra-processed foods is associated with higher odds of overweight and obesity amongst under-five children: A national cross-sectional study in Lebanon

INTRODUCTION

Limited evidence exists on the relationship between ultra-processed food (UPF) consumption and overweight/obesity amongst young children. This study aimed to assess UPF consumption, its socioeconomic correlates and its association with overweight/obesity amongst under-five children in Lebanon.

MATERIALS AND METHODS

Data pertinent to children aged 6 months to 4.9 years (n = 893) from a cross-sectional national survey were used. Anthropometric measurements were obtained, and multi-component questionnaires were administered to mothers. Dietary intake was assessed using the 24-h recall approach. NOVA classification was used to assign food items into four groups according to the extent of industrial processing. Contributions of each group to total energy intake (EI) and macronutrient and micronutrient intakes were estimated. Regression models were conducted to explore the correlates of UPF consumption as well as the association between UPF consumption and overweight/obesity status.

RESULTS

UPFs were found to contribute 47% of daily EI. Girls and children with higher household income had significantly higher UPF intakes. Children whose mothers had an intermediate, high school, or technical diploma and were employed and whose fathers had higher education levels consumed significantly less EI from UPFs. Children whose %EI fell within the second and third tertiles of UPF intake had significantly higher odds of overweight/obesity as compared to those in the first tertile (adjusted odds ratio [AOR]: 1.21, 95% confidence interval [CI]: 1.09, 1.32 and AOR: 1.61, 95% CI: 1.47, 1.76, respectively), after adjusting for confounders.

CONCLUSION

The high intake of UPFs coupled with its association with overweight/obesity call for public health nutrition interventions aimed at improving feeding and dietary practices in this age group.

Effects of the dyadic FirstStep2Health intervention on parents' behaviour and anthropometric outcomes: a secondary analysis of a cluster randomised trial

OBJECTIVES

This study aimed to examine the preliminary efficacy of the FirstStep2Health versus usual care control on improving parents' lifestyle behaviours (moderate to vigorous physical activity, screen time, fruit/vegetable and fibre intake, skin carotenoids), nutrition and physical activity knowledge, self-efficacy, support, parenting style, feeding practices, home environment, anthropometric outcomes (body mass index, % body fat) and blood pressure from baseline to postintervention after adjusting for random cluster effects.

DESIGN

A cluster randomised controlled trial with 10 Head Start daycare centres (five intervention, five control) was conducted using computer-generated randomisation after baseline data collection.

SETTING

US Head Start daycare centres.

PARTICIPANTS

95 parent-child dyads (53 intervention, 42 control).

INTERVENTIONS

The 16-week, dyadic, FirstStep2Health intervention included: (1) a daycare-based child programme on healthy mindful eating and physical activity, (2) child letters to parents to connect school learning with home practice, (3) social media-based parent programme to assist parents to promote healthy eating and physical activity at home, (4) virtual group parent meetings via Zoom on topics related to healthy eating and physical activity and (5) weekly motivational messages to increase parental motivation to build a healthy home environment.

RESULTS

Mixed-effect models were used to examine intervention effects, adjusting for baseline outcome and cluster effects at the daycare and classroom levels. Intervention parents engaged in more moderate to vigorous physical activity (B=0.49, p=0.874) postintervention than controls, although not significantly. However, intervention parents showed significantly higher nutrition knowledge (B=0.87, p=0.009), physical activity knowledge (B=0.95, p=0.049), nutrition self-efficacy (B=0.74, p=0.025) and physical activity self-efficacy (B=0.86, p=0.013) compared with controls at postintervention. Fibre intake was also significantly higher (B=2.99, p=0.049), and intervention parents had lower % body fat (B=-2.56, p=0.005) and systolic blood pressure (B=-10.98, p=0.005) postintervention. No significant effects were found for fruits/vegetables intake, parental support for healthy behaviours, home physical activity environment or authoritative parenting style.

CONCLUSIONS

Future endeavours to proactively engage parents in a dyadic childhood obesity prevention approach such as the FirstStep2Health intervention are warranted to improve outcomes among both children and parents.

TRIAL REGISTRATION NUMBER

NCT04164277.

FirstStep2Health: A cluster randomised trial to promote healthy behaviours and prevent obesity amongst low-income preschoolers

OBJECTIVE

To evaluate the preliminary effects of a theory-based, multi-component intervention on improving healthy lifestyle behaviours and preventing obesity amongst low-income preschoolers.

METHODS

A cluster randomised controlled trial was conducted at 10 daycare centres. The 16-week FirstStep2Health intervention, grounded in the Actor-Partner Interdependence Model and the Social Cognitive Theory, included five components: a Facebook-based parent programme, three virtual parent meetings, three weekly motivational text messages, parent-child learning via weekly child letters and daycare centre-based child programme.

RESULTS

A total of 95 preschoolers (53 intervention and 42 control) participated. Preschoolers' mean age was 49.27 months, with 57.9% being female, 12.6% being Hispanic and 40% being African American. The intervention significantly decreased intervention preschoolers' fat intake (B = -33.76, p = 0.047) and % body fat (B = -1.18, p = 0.036) compared to the control. During year 2, there were significant intervention effects on increasing skin carotenoids (B = 87.06, p = 0.035). Although not statistically significant, the intervention showed positive effects on increasing preschoolers' fruit/vegetable intake; and decreasing screen time, body mass index z-score and proportion of overweight/obesity.

CONCLUSIONS

Even with some potential limitations (small sample size, measurement concerns and confounding with Coronavirus Disease 2019 pandemic), the study's results support the preliminary efficacy of the FirstStep2Health intervention in preventing obesity amongst low-income racially diverse preschoolers.

Organized Physical Activity Program Participation, Physical Activity, and Related Psychosocial Factors Among Urban Adolescents

The study purpose was to examine whether adolescents who participated in organized physical activity (PA) programs differed from nonparticipants in motivation, social support, and self-efficacy related to PA; PA (min/hr); and sedentary screen time behavior. Thirty-nine 5th-7th grade adolescents participated in organized PA programs; 41 did not. Approximately 56.3% were Black, and 52.5% had annual family incomes <$20,000. Compared to nonparticipants, those who participated reported significantly higher social support (M = 2.32 vs. 3.13, p < .001) and fewer hours watching television or movies on a usual weekend day (M = 2.49 vs. 1.59, p = .016); and had higher accelerometer-measured vigorous PA (M = 0.58 vs. 1.04, p = .009) and moderate-to-vigorous PA (M = 2.48 vs. 3.45, p = .035). Involving adolescents in organized PA programs may be important for improving their moderate-to-vigorous PA, vigorous PA, and related psychosocial factors, as well as reducing sedentary screen time behavior.

Barriers and facilitators of physical activity, sedentary and sleep behaviours in 3 to 4-year-old children from low-income families: a study protocol

BACKGROUND

This study will evaluate the barriers and facilitators that families experience in adhering to the 24-hour movement behaviours guidelines as outlined by World Health Organisation (WHO).

METHODS

The study is a mixed-methods study and will recruit between 20 to 30 low-income families with children aged 3- to 4-years living in Scotland. For the quantitative part, children will be asked to wear an Actigraph (GT3X +) accelerometer to measure physical activity, sedentary behaviour, and sleep. Parents/guardians will be asked to keep an activity diary outlining when their child has had to remove the device (i.e., showering, bathing, swimming) and record the child's screen time each day. Once the data has been analysed, a unique activity profile chart will be sent out to each family illustrating their child's 24-hour movement behaviours (i.e., time spent active, time spent sedentary and on screens, time spent sleeping). The activity profile will provide a day-by-day output as well as a weekly average for each of the 24-hour movement behaviours. Qualitative data will be collected using the Asynchronous Remote Communities method (ARC). The ARC involves participants completing activities using an online closed Facebook group. Parents/guardians of 3- to 4-year-old children will be asked to engage in group discussion tasks using the private and closed-group online platform (a minimum of 6 and a maximum of 8 families per discussion group). The quantitative data collated from the questionnaire and activity monitor will be presented through descriptive analysis and after the 6-week asynchronous process is complete, qualitative data will be collated and analysed using Braun and Clarke's reflexive approach to thematic analysis.

DISCUSSION

The data collected will provide an understanding of what barriers and facilitators parent's/guardians' experience in relation to adhering to the 24-hour movement behaviour guidelines. This could potentially lead to the design and implementation of support and interventions to help families struggling to adhere to the guidelines.

The influence of reliability and variability of objectively measured physical activity on associations with lower body muscle strength in young children

It is not known how extended or multiple monitoring periods affect associations between accelerometer-measured physical activity and outcomes. The aim of this study was to examine how accelerometer monitoring length influenced cross-sectional and prospective associations for physical activity with lower body muscle strength in young children. 176 Norwegian 2-6-year-old children had 3 valid 14-day periods of accelerometer monitoring (ActiGraph GT3×+) between September 2015 and May 2016 (baseline) as well as baseline and 4-year follow-up measurements of standing long jump. We analysed physical activity using a descriptor with 4 intensities using 6 different monitoring lengths both within and across monitoring periods (1 day, 3 days, 1 week, 2 weeks, 3 weeks, 6 weeks) and determined associations with lower body muscle strength using multivariate pattern analysis. We found that the strength of cross-sectional associations with lower body muscle strength improved for longer monitoring periods (explained variances = 7.7%, 9.8%, 11.8%, 15.8%, 18.4% and 22.9% for 1 day, 3 days, 1 week, 2 weeks, 3 weeks and 6 weeks of measurement). Longitudinal associations were weaker and less clear. Our findings suggest that multiple extended physical activity monitoring periods improve the validity of the study findings regarding associations between physical activity and relevant outcomes.

Using unsupervised machine learning to quantify physical activity from accelerometry in a diverse and rapidly changing population

Accelerometers are widely used to measure physical activity behaviour, including in children. The traditional method for processing acceleration data uses cut points to define physical activity intensity, relying on calibration studies that relate the magnitude of acceleration to energy expenditure. However, these relationships do not generalise across diverse populations and hence they must be parametrised for each subpopulation (e.g., age groups) which is costly and makes studies across diverse populations and over time difficult. A data-driven approach that allows physical activity intensity states to emerge from the data, without relying on parameters derived from external populations, offers a new perspective on this problem and potentially improved results. We applied an unsupervised machine learning approach, namely a hidden semi-Markov model, to segment and cluster the raw accelerometer data recorded (using a waist-worn ActiGraph GT3X+) from 279 children (9-38 months old) with a diverse range of developmental abilities (measured using the Paediatric Evaluation of Disability Inventory-Computer Adaptive Testing measure). We benchmarked this analysis with the cut points approach, calculated using thresholds from the literature which had been validated using the same device and for a population which most closely matched ours. Time spent active as measured by this unsupervised approach correlated more strongly with PEDI-CAT measures of the child's mobility (R2: 0.51 vs 0.39), social-cognitive capacity (R2: 0.32 vs 0.20), responsibility (R2: 0.21 vs 0.13), daily activity (R2: 0.35 vs 0.24), and age (R2: 0.15 vs 0.1) than that measured using the cut points approach. Unsupervised machine learning offers the potential to provide a more sensitive, appropriate, and cost-effective approach to quantifying physical activity behaviour in diverse populations, compared to the current cut points approach. This, in turn, supports research that is more inclusive of diverse or rapidly changing populations.

Outdoor Kindergartens: A Structural Way to Improve Early Physical Activity Behaviour?

BACKGROUND

Studies have shown that outdoor play in nature is associated with a higher physical activity level than indoor play. We aimed to examine the effect of outdoor versus conventional kindergartens on objectively measured physical activity.

METHOD

Using a pre-test-post-test design, we collected data in four kindergartens that provided a rotating outdoor and conventional kindergarten setting. Step counts were measured during one week in the outdoor setting and one week in the conventional setting. Differences in step counts between the outdoor and conventional setting were analysed using a paired t-test.

RESULTS

In total, 74 children were included. There was no statistically significant difference in total daily step counts between children in the two settings. When we looked at step counts during kindergarten hours, we saw that children were more physically active in the outdoor setting compared to the conventional setting (mean difference: 1089, p < 0.0001). When we looked at activity during time outside the kindergarten, we discovered that children had a lower step count in the outdoor setting as compared to the conventional setting (mean difference -652, p = 0.01).

CONCLUSION

This study indicates that children are more physically active during the time they spend in outdoor kindergartens compared to conventional kindergartens, but may compensate with more inactivity outside kindergarten hours.

Preschool Children's Physical Activity and Community Environment: A Cross-Sectional Study of Two Cities in China

Research on the relationship between preschool children's physical activity (PA) and community environment is limited and inconclusive, yet understanding this relationship is important to acquire sufficient information to guide the development of intervention programs. This study aims to objectively measure preschool children's PA and examine associations between PA and the community environments. A total of 471 preschool children aged 3-6 years old were recruited from eight kindergartens in Beijing and Zhengzhou. PA was measured by accelerometers. Light PA (LPA), moderate PA (MPA), and vigorous PA (VPA) were computed on the basis of cutoff points developed for preschool children. Moderate-to-vigorous PA (MVPA), and total PA (TPA) were obtained by calculation. Children's active transportation modes were indicated by the frequency of active trips (FAT) reported by parents. The community environment was collected by parental scales. Multivariate linear regression was used to analyze the associations between PA and the community environment. In total, 304 preschool children (mean age 5.07 ± 0.94 years, 50.66% boys) were included in the final analysis. Children spent an average of 77.58 ± 18.78 min/day in MVPA and 173.26 ± 30.38 min/day in TPA. Linear regression showed that 'parental perception of appropriate walking distance' was associated with nearly half of the indicators of the children's PA. 'Public activity facilities near the community' was associated with FAT for overall children (B = 0.099, 95% CI = 0.014, 0.183). 'Community transportation environment' was associated with overall children's average day LPA (B = 4.034, 95% CI = 0.012, 8.056), weekend LPA (B = 8.278, 95% CI = 1.900, 14.657), MPA (B = 4.485, 95% CI = 0.613, 8.357), TPA (B = 14.777, 95% CI = 2.130, 27.424), and FAT for girls (B = -0.223, 95% CI = -0.443, -0.003). Furthermore, 'community personal safety' was associated with boys' weekday VPA (B = -3.012, 95% CI = -5.946, 0.079). Parental perception of appropriate walking distances, improvement of PA facilities, community personal safety, and the community transportation environment all contribute to the prevention of preschool children's PA patterns deterioration.

The Feel4Diabetes intervention: effectiveness on 24-hour physical behaviour composition in families at risk for diabetes development

The Feel4Diabetes project conducted a 2-year intervention aiming to encourage healthy behaviours in families in six European countries. Within this paper, the intervention effect was evaluated after the first intervention year on 24-hour physical behaviour composition in Belgian families at risk for type 2 diabetes. Parents’ and children’s levels of physical activity (PA) and sedentary behaviour (SB) were objectively measured and sleep duration was self-reported. Valid data were obtained in 82 children (mean age: 8.2 ± 0.84; 50.0% boys) and 72 parents (mean age: 40.1 ± 5.5; 27.8% fathers). Data were analysed using a compositional data approach, and mixed models were used to take clustering into account. Results showed that for children, the mean baseline composition of the 24-hour day in sleep, SB, light and moderate-to-vigorous PA for the intervention group was (11 hours 18 minutes; 6 hours 33 minutes; 5 hours 02 minutes, 1 hour 08 minutes) and for the control group (11 hours 18 minutes; 6 hours 35 minutes; 5 hours 04 minutes; 1 hour 06 minutes), respectively. For parents, the mean baseline composition was for the intervention group (8 hours 12 minutes; 9 hours 36 minutes; 5 hours 43 minutes; 27 minutes) and for the control group (8 hours 00 minute; 9 hours 00 minute; 6 hours 27 minutes; 33 minutes). No significant intervention effects were found on 24-hour physical behaviour composition of either parents or children (p = 0.19 and p = 0.21, respectively). A relatively small study population and a poor attendance rate among parents could maybe explain the lack of effectiveness. More effective strategies are needed to retain vulnerable families in interventions. Furthermore, future approaches to improve the 24-hour physical behaviour composition should maybe focus more specifically on PA, SB and sleep, and involve teachers, children and parents in the design of the intervention. Trial registration: NCT02393872 in ClinicalTrials.gov.

Examining Relationships among Chinese Preschool Children's Meeting 24-Hour Movement Guidelines and Fundamental Movement Skills

Background: Few studies have investigated associations between meeting 24-Hour Movement Guidelines and preschool children’s fundamental movement skills (FMS). This study aimed to investigate the associations between Chinese preschoolers meeting various combinations of the Guidelines and FMS, as well as examining gender differences across those outcomes. Methods: A total of 322 preschool children (181 boys and 141 girls) aged 3−6 years old were recruited from five early-childhood education and care services in China. Children’s 7-day physical activity (PA) was assessed using accelerometry, and screen time (ST) and sleep duration were reported by their parents. FMS were assessed by Test of Gross Motor Development 3. Descriptive statistics and gender differences in children’s meeting the Guidelines and FMS were calculated using t-tests for continuous variables and Chi-square tests for categorical variables. Results: Most preschoolers met the sleep and ST guidelines, but only 22.3% met the PA guidelines; 4% of preschoolers did not meet any of the recommendations, while 9.3% met all three recommendations. Boys reported significantly higher compliance with all combined recommendations. There were positive associations between meeting the PA guidelines and both locomotor (β = 0.49; p < 0.001) and object control skills (β = 0.21; p < 0.001). A significantly positive relationship was identified between meeting PA + sleep guidelines and locomotor skills (β = −0.16; p = 0.02). A significantly negative association was observed between preschoolers’ meeting sleep + ST guidelines and locomotor skills (β = 0.31; p = 0.001). Conclusion: Few preschoolers met all three movement behavior guidelines. The findings suggest that PA levels, especially MVPA, are important for the promotion of FMS. Meanwhile, the impacts of ST and sleep on motor development cannot be neglected.

Environmental correlates of sedentary behaviors and physical activity in Chinese preschool children: A cross-sectional study

OBJECTIVE

This cross-sectional study examined environmental correlates of sedentary behavior (SB) and physical activity (PA) in preschool children in the urban area of Tianjin, China.

METHODS

Data were collected from the Physical Activity and Health in Tianjin Chinese Children study, involving healthy children 3-6 years old and their families. In all children (n = 980), leisure-time SB (LTSB) and leisure-time PA (LTPA) were reported in min/day by parents. In a subgroup (n = 134), overall sedentary time, light PA, and moderate-to-vigorous PA (MVPA) were objectively measured using ActiGraph accelerometry (≥3 days, ≥10 h/day). Environmental correlates were collected using a questionnaire that included home and neighborhood characteristics (e.g., traffic safety, presence of physical activity facilities) and children's behaviors. Potential correlates were identified using linear regression analysis.

RESULTS

Multiple linear regression analysis showed that "having grandparents as primary caregivers" (βs and 95% confidence intervals (95%CIs) for overall sedentary time: 29.7 (2.1-57.2); LTSB (ln): 0.19 (0.11-0.28)) and "having a television (for LTSB (ln): 0.13 (0.00-0.25)) or computer (for LTSB (ln): 0.13 (0.03-0.23)) in the child's bedroom" were both associated with higher SB. Furthermore, "having grandparents as primary caregivers" was associated with less MVPA (β (95%CI): -7.6 (-14.1 to -1.2)), and "active commuting to school by walking" correlated with more MVPA (β (95%CI): 9.8 (2.2-17.4)). The path model showed that "more neighborhood PA facilities close to home" was indirectly related to higher LTPA (ln), which was partly mediated by "outdoor play" (path coefficients (95%CI): 0.005 (0.002-0.008)) and "going to these facilities more often" (path coefficients (95%CI): 0.013 (0.008-0.018)). Traffic safety was not a correlate.

CONCLUSION

Family structure and media exposure in the home maybe important factors in shaping preschoolers' PA patterns. Built environmental correlates could indirectly influence preschoolers' LTPA through parental help with engaging in active behaviors.

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.

Determinants of High Fat Mass Index in Preschoolers Living in Brazilian Urban Areas

OBJECTIVE

Determine the social, environmental, and personal factors associated with high fat mass index in preschoolers.

DESIGN

A quantitative, exploratory, and cross-sectional study.

SETTING AND PARTICIPANTS

Fifty-one Brazilian preschoolers from public schools living in urban areas.

MAIN OUTCOME MEASURE(S)

The preschoolers' fat mass index was determined using dual-energy radiological absorptiometry. The quality of home and school environments were accessed using the Early Childhood Home Observation for Measurement of the Environment and Early Childhood Environment Rating Scales. The physical activity levels were recorded by accelerometers. The daily energy intake was recorded and sociodemographic data using the Brazilian Economic Classification criterion. Data on exposure time to screens and parental obesity were collected according to the parents' reports.

ANALYSIS

Data analyses were performed using simple and multiple regressions models.

RESULTS

Parental obesity (β, 0.516; 95% confidence interval [CI], 2.078-5.133), high quality of environmental stimulation of home (β, 0.429; 95% CI, 1.294-4.023), and high exposure time to screens (β, 0.256; 95% CI, 0.215-2.554) explained 43% of preschoolers' high fat mass index.

CONCLUSIONS AND IMPLICATIONS

Identification of parental obesity, high quality of environmental stimulation of home, and high exposure time to screens as the most important determinants of the high fat mass index in preschoolers from Brazilian urban areas.

Effect of a Fundamental Motor Skills Intervention on Fundamental Motor Skill and Physical Activity in a Preschool Setting: A Cluster Randomized Controlled Trial

PURPOSE

To determine the effect of a 12-week fundamental motor skill (FMS) program on FMS and physical activity (PA) on preschool-aged children.

METHOD

A cluster randomized controlled trial. The intervention (PhysicaL ActivitY and Fundamental Motor Skills in Pre-schoolers [PLAYFun] Program) was a 12-week games-based program, delivered directly to the children in childcare centers by exercise physiologists. Children in the control arm received the usual preschool curriculum. Outcomes included FMS competence (Test of Gross Motor Development-2) and PA (accelerometer) assessed at baseline, 12 weeks, and 24 weeks (12-wk postintervention).

RESULTS

Fifty children (mean age = 4.0 [0.6] y; 54% male) were recruited from 4 childcare centers. Two centers were randomized to PLAYFun and 2 centers were randomized to the waitlist control group. Children attended on average 2.0 (1.0) 40-minute sessions per week. The PLAYFun participants demonstrated significant increases in object control (P < .001) and total FMS (P = .010) competence at week 12, compared with controls in a group × time interaction. Girls, but not boys, in PLAYFun significantly increased moderate to vigorous PA after the intervention (P = .004). These increases were not maintained 12-week postcompletion of PLAYFun.

CONCLUSIONS

The PLAYFun Program is effective at improving FMS competence in boys and girls and increasing PA in girls. However, improvements are not maintained when opportunities to practice are not sustained.

Parents' Inadequate Estimate of Their Children's Objectively Physical Activity Level

This study aimed to investigate parents' estimation of their preschool children's leisure-time physical activity (PA) and the correlation between parents' reported participation in PA with their children in leisure time and their children's PA levels. A total of 244 Norwegian preschool children aged 4-6 and their parents were enrolled in the study. According to standard protocols, the children's PA level was measured with Actigraph GT1M accelerometers. The parents completed a questionnaire that provided information about their estimation of their children's PA and their reported participation in their children's PA. Correlation analyses and scatter plots showed no significant association between parents' estimation of their children's PA level at leisure time and the children's objectively measured PA level. Only 5% of the parents estimated their children's PA level correctly. In general, the parents overestimated their children's PA levels by three times. Furthermore, the results found no significant correlation between children's PA levels at leisure time and parents' reported participation in PA with their children. Our findings indicate that parents' self-estimation of their children's PA is inaccurate, which is problematic. Considering that the PA levels of many children are too low to fulfill internationally established health recommendations, parents' 'wrong' perception about their children's PA urgently needs to be addressed and rectified.

Is body fat mass associated with worse gross motor skills in preschoolers? An exploratory study

We compared the motor competence between overweight/obese and eutrophic preschoolers with similar physical activity levels, age, socioeconomic status, maternal education, quality of the home environment and quality of the school environment. We also investigated to what extent excess body fat mass explains gross motor skills in preschoolers. A cross-sectional quantitative and exploratory study was conducted with 48 preschoolers assigned into eutrophic and overweight/obese groups. Overweight/obese preschoolers had worse Locomotor subtest standard scores than the eutrophic ones (p = 0.01), but similar Object Control subtest and Gross Motor Quotient scores (p > 0.05). Excess body fat mass explained 12% of the low Locomotor subtest standard scores in preschoolers (R2 = 0.12; p = 0.007). Excess body fat mass was associated with worse locomotor skills when the model was adjusted for physical activity levels, age, socioeconomic status, maternal education, quality of the home environment and quality of the school environment. Thus, excess body fat mass partly explains lower locomotor skills in preschoolers.

Physical environmental opportunities for active play and physical activity level in preschoolers: a multicriteria analysis

BACKGROUND

Active play opportunities seems to influence the level of physical activity during childhood. However, a gap remains about which environmental opportunities including the daycare physical environment could have a positive impact on the level of physical activity in preschoolers.

OBJECTIVES

(1) To develop an index to measure the environmental opportunities of free active play for preschoolers of middle-income countries; (2) to check the relationship and contribution of the index to explain objectively the level of physical activity.

METHODS

A quantitative, cross-sectional, exploratory study with 51 preschool children. The established criteria for the index according to the literature were: (1) Outdoor time on typical days of the week. (2) Outdoor time on a typical weekend day. (3) The presence of internal space and external environment in the child's home that allows playing. (4) Presence of patio with space for games at the school. (5) Presence of a playground with a toy at the school. We applied multi-attribute utility theory for the determination of the multicriteria index of physical environmental opportunities. Pearson's correlation analysis and simple linear regression were used to verify the association between the index and the physical activity level.

RESULTS

The index showed a positive correlation with the level of physical activity, e.g., the average time of MVPA (r = 0.408, p = 0.003). The univariate linear regression demonstrated that the quality of physical environmental opportunities for physical activity explained 20% of the preschooler's classification as active and 16% of the time in moderate to vigorous physical activity (p < 0.001).

CONCLUSION

Physical environmental opportunities for active play have a positive effect on physical activity in preschoolers and should be encouraged in different social segments.

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.

Inactive Lifestyles among Young Children with Innocent Murmurs or Congenital Heart Disease Regardless of Disease Severity or Treatment

BACKGROUND

Sedentary lifestyle morbidities are common among children with congenital heart disease (CHD). Understanding the physical activity trajectory from early childhood could enhance intervention timing/effectiveness.

METHODS

154 children (56% male) were recruited at 12-47 months of age for this prospective, longitudinal, observational study. Physical activity and sedentary behaviour (7-day accelerometry) and motor skill (Peabody Developmental Motor Scales-2) were assessed every 8 months until 5 years of age and then annually. Mixed effect repeated measures regression models described outcome trajectories across study assessments.

RESULTS

Children had an innocent heart murmur (n=28), CHD with insignificant hemodynamics not requiring treatment (n=47), CHD treated by catheterization or surgery without cardiopulmonary bypass (n=31), or CHD treated surgically with bypass (n=48). Motor skill was age appropriate (Peabody 49.0±8.4) but participants had lower physical activity (143±41 mins/day) and higher sedentary time (598±89 mins/day) than healthy peers, starting at 18 months of age. Movement behaviours were not related to treatment group (p>0.10), and physical activity was below the recommended 180 mins/day. Over time, physical activity, sedentary time and motor skill were primarily related to the baseline measure of each outcome (p<0.001).

CONCLUSIONS

Children with simple or complex CHD or innocent heart murmurs have an increased risk for sedentary lifestyles. Their physical activity and sedentary behaviours are established prior to 2 years of age, persist until school age, and are unrelated to motor skill. These results emphasize the need for interventions targeting the youngest children seen in a cardiac clinic, regardless of CHD diagnosis or innocent murmur.

The Use of a Nonrefundable Tax Credit to Increase Children's Participation in Physical Activity in Alberta, Canada

BACKGROUND

Potential income disparities were examined in the (1) awareness and uptake of the Children's Fitness Tax Credit (CFTC), and (2) physical activity (PA) of children from families who did and did not claim the credit in Alberta, Canada in 2012 and 2014.

METHODS

Secondary analyses of 3 cross-sectional data sets of grade 5 students (10-11 y) were performed, including Alberta Project Promoting healthy Living for Everyone Schools 2012 (N = 1037), and Raising healthy Eating and Active Living Kids Alberta 2012 (N = 2676), and 2014 (N = 3125). Parents reported whether they claimed the CFTC in the previous year, their education and household income, and their child's gender and PA. Children self-reported their PA from the previous 7 days. In Alberta Project Promoting healthy Living for Everyone Schools, children also wore pedometers. Analyses adjusted for clustering within schools and demographic factors.

RESULTS

Higher income families (≥$50,000/y) were more likely to be aware of and to have claimed the CFTC compared with low-income families (<$50,000/y). The CFTC was associated with organized PA with larger associations for higher-income families (odds ratio = 9.03-9.32, Ps < .001) compared with lower-income families (odds ratio = 3.27-4.05, Ps < .01). No associations existed for overall PA or pedometer steps with the CFTC.

CONCLUSIONS

Income disparities exist in the awareness, uptake, and potential impact of the CFTC. Tax credits are not effective in promoting overall PA.

Laurent CW, Spencer RMC. Unhealthy Diet Is Associated With Poor Sleep in Preschool-Aged Children

Unhealthy dietary choices are associated with poor sleep in children through adults. Yet, how diet and sleep are related in early childhood, when diet is reliant on parent choices around food availability, is unknown. The authors aimed to explore how frequency of fruit, vegetable, fast food, and soda consumption are associated with preschool children's sleep quality. They also considered how parenting factors may impact the relationship between children's sleep and diet. Actigraphy data were collected from 383 children 33-70 months old. Caregivers reported on child food and beverage frequency, demographics, and health items. Parenting strategies were assessed using the Parenting Scale. Multiple linear regression was used to examine associations between sleep and dietary measures with socioeconomic status, race-ethnicity, physical activity, and body mass index as covariates. Shorter nap duration was associated with more frequent consumption of fruits and vegetables (B = -3.6, p = .03). Shorter nighttime and 24-hr sleep durations were associated with more frequent consumption of fast food (B = -6.5, p = .01; B = -5.8, p = .01). Shorter nighttime sleep and later sleep onset were associated with more frequent soda consumption (B = -9.2, p = .01; B = 0.23, p = .001). Use of ineffective parenting strategies was negatively associated with fruit and vegetable consumption (r = -.29, p = .01) and positively associated with soda consumption (r = .25, p = .02) but was unrelated to sleep measures. Thus, ineffective parenting strategies may underlie child access to unhealthy foods, which, in turn, contributes to poor sleep. Encouraging healthier dietary habits and educating caregivers on how to reinforce such practices may lead to better sleep outcomes in early childhood.

The Importance of Parents' Income and Education Level in Relation to Their Preschool Children's Activity Level at Leisure

Previous research indicate that socioeconomic status positively corresponds with adults’ and adolescents’ physical activity levels. This study investigated the relationship between parents’ education and income, and preschool children’s physical activity level. A total of 244 Norwegian preschool children aged four to six and their parents were enrolled in the study. The children wore an Actigraph GT1M accelerometer for seven consecutive days to measure their physical activity level. Parents completed a questionnaire that provided information about their education level and income level. To examine the relationship between the parents’ education and income and their children’s physical activity level at leisure, the Kruskal-Wallis H test was conducted. The results revealed that neither mothers’ nor fathers’ education level or income, were associated with their children’s minutes in moderate to vigorous physical activity (MVPA) at leisure. The preschool curriculum of Norway may be one explanation why socioeconomic status was not linked to physical activity in this study. Another possibility is that this study was limited to full-time students with two parents. More research is needed to determine whether parent income or education is linked to physical activity among more diverse or older children in Norway.

Physical Activity Levels among Preschool-Aged Children in Family Child Care Homes: A Comparison between Hispanic and Non-Hispanic Children Using Accelerometry

Obesity prevalence among Hispanic children is twice that of non-Hispanic white children; Hispanic children may also engage in less physical activity (PA) compared to non-Hispanic white children. A large number of U.S. preschool-aged children are cared for in Family Child Care Homes (FCCH), yet few studies have examined PA levels and ethnicity differences in PA levels among these children. We examine baseline data from a cluster-randomized trial (Healthy Start/Comienzos Sanos) to improve food and PA environments in FCCHs. Children aged 2-to-5-years (n = 342) wore triaxial accelerometers for two days in FCCHs. Variables examined include percentage of time (%) spent in sedentary, and light, moderate, and vigorous PA. The full dataset (n = 342) indicated sedentary behavior 62% ± 11% of the time and only 10% ± 5% of the time spent in moderate-to-vigorous PA. Among children in the upper-median half of wear-time (n = 176), Hispanic children had significantly greater % sedentary time vs. Non-Hispanic children (66.2% ± 8.3% vs. 62.6% ± 6.9%, p = 0.007), and lower % light PA (25.4% ± 6.3% vs. 27.7% ± 4.9%, p = 0.008) and moderate PA (5.5% ± 2.1% vs. 6.4% ± 2.2%, p = 0.018). Our results highlight that PA levels were lower among our sample compared to previous studies, and that Hispanic children were more sedentary and less active compared to non-Hispanic white children.

Slow wave sleep in naps supports episodic memories in early childhood

Naps have been shown to benefit visuospatial learning in early childhood. This benefit has been associated with sleep spindles during the nap. However, whether young children's naps and their accompanying physiology benefit other forms of declarative learning is unknown. Using a novel storybook task, we found performance in children (N = 22, mean age = 51.23 months) was better following a nap compared to performance following an equivalent interval spent awake. Moreover, performance remained better the following day if a nap followed learning. Change in post-nap performance was positively associated with the amount of time spent in slow wave sleep during the nap. This suggests that slow wave sleep in naps may support episodic memory consolidation in early childhood. Taken in conjunction with prior work, these results suggest that multiple features of brain physiology during naps may contribute to declarative memory processing in early childhood.

Objective Measurement of Physical Activity Attributed to a Park-Based Afterschool Program

BACKGROUND

Only 24% of US youth meet physical activity recommendations set by the Centers for Disease Control and Prevention. Research demonstrates that community-based programs provide underresourced minority youth with opportunities for routine physical activity, although limited work draws from accelerometry data. This study objectively assessed youth physical activity attributable to participation (vs nonparticipation) days in a park-based afterschool program in Miami-Dade County, Miami, FL.

METHODS

Participants' (n = 66; 60% male; 57% white Hispanic, 25% non-Hispanic black, 14% Black Hispanic, mean age = 10.2 y) physical activity was assessed April to May 2019 over 10 days across 7 park sites using Fitbit (Charge 2) devices. Separate repeated-measures multilevel models were developed to assess the relationship between program daily attendance and total (1) moderate to vigorous physical activity minutes and (2) step counts per day.

RESULTS

Models adjusted for individual-level age, sex, race/ethnicity, poverty, and clustering by park showed significantly higher moderate to vigorous physical activity minutes (β = 25.33 more minutes per day; 95% confidence interval, 7.0 to 43.7, P < .01) and step counts (β = 4067.8 more steps per day; 95% confidence interval, 3171.8 to 4963.8, P < .001) on days when youth did versus did not attend the program.

CONCLUSIONS

Study findings suggest that park-based programs may support underserved youth in achieving daily physical activity recommendations.

Validation of the Physical Activity Questions in the World Health Organization Health Behavior in School-Aged Children Survey Using Accelerometer Data in Japanese Children and Adolescents

BACKGROUND

An international physical activity (PA) questionnaire is beneficial to make cross-country comparisons among children and adolescents. This study assesses the validity of the PA questions in the World Health Organization Health Behavior in School-Aged Children (WHO HBSC) survey in Japanese children and adolescents.

METHODS

Participants were fifth- to sixth-grade Japanese primary school students (67 students aged 10.8 [0.5] y) and first- to third-grade junior high school students (108 students aged 13.0 [0.7] y). The Japanese version of the PA questions in the WHO HBSC (WHO HBSC-J) was used. To assess the validity of the PA questions, the authors used a partial correlation adjusted for sex, age, and relative weight between the answers to the survey questions and objectively measured moderate to vigorous PA (MVPA) by an accelerometer.

RESULTS

A significant positive correlation was found between accelerometer-measured MVPA and the number of reported days with at least 60 minutes/day of MVPA in primary school students (r = .39, P = .002) and junior high school students (r = .32, P < .001).

CONCLUSION

The HBSC-J has moderate validity for evaluating MVPA in Japanese primary school and junior high school students.

The Role of Children's Dietary Pattern and Physical Activity in the Association Between Breastfeeding and BMI at Age 5: The GECKO Drenthe Cohort

Objectives

Breastfeeding is protective against childhood obesity, but the role of childhood lifestyle in this association is unclear. We investigated whether physical activity and dietary pattern at age 5 differed between breastfed and non-breastfed children, and how they relate to Body Mass Index (BMI) Z-scores.

Methods

1477 children of the Dutch GECKO Drenthe birth cohort were included. At one month, children were categorized as breastfed (receiving breast milk exclusively or in combination with formula milk) or non-breastfed (receiving formula milk exclusively). At age 5, height and weight were objectively measured, physical activity was measured by ActiGraph GT3x and dietary patterns were assessed with a parent-reported food pattern questionnaire, assessing the consumption frequency of selected food items at seven occasions over the day.

Results

Non-breastfed children had higher BMI Z-scores (0.36 ± 0.90 vs. 0.20 ± 0.80 SD, p = 0.002), more frequently consumed sugar-sweetened beverages (25.0 ± 10.5 vs. 22.5 ± 9.71 times per week, p < 0.001), and consumed relatively less whole-wheat or brown bread (p = 0.007). Differences in sugar-sweetened beverage consumption were most pronounced during main meals. Total fruit consumption, sedentary time and moderate-to-vigorous physical activity levels did not differ between the groups. Multivariable adjusted linear regression analyses showed that the differences in BMI-z score between non-breastfed and breastfed children were not explained by the differences in sugar-sweetened beverages or type of bread consumed.

Conclusions

Infant breastfeeding itself is indicative of healthy dietary behaviors in early life, and is also more likely to be followed by a favorable dietary pattern at toddler age. However, the differences in dietary habits between breastfed and non-breastfed children did not explain the difference in BMI Z-score at the age of 5.

Electronic supplementary material

The online version of this article (10.1007/s10995-020-03063-6) contains supplementary material, which is available to authorized users.

Association between 24-hour movement guidelines and physical fitness in children

BACKGROUND

Physical fitness levels in Japanese children are lower than those in the 1980s. Twenty-four hour movement guidelines were recently developed to improve both present and future health of children. This study examined whether meeting the 24 h movement guidelines was associated with physical fitness measures in primary school children.

METHODS

Participants were 243 Japanese children (9.4 ± 1.7 years). Moderate-to-vigorous physical activity (MVPA) was evaluated using accelerometry. Sleep duration and screen time were reported. Physical fitness was assessed by grip strength, sit-ups, sitting trunk flexion, and 20 m shuttle run test. Meeting the 24 h movement guidelines was defined as: 9-11 h / night of sleep, ≤2 h/day of screen time, and at least 60 min/day of MVPA. The associations between physical fitness and the recommendations were analyzed using analysis of covariance.

RESULTS

Children meeting the MVPA recommendation alone performed better on the 20 m shuttle run and sit-up test compared to those not meeting the recommendation (number of laps: 41 vs 36, P = 0.009 and number of repetitions: 16.3 vs 14.7, P = 0.021). Children meeting the combination of MVPA and sleep recommendation scored significantly higher on the sit-up test compared to those not meeting the recommendations (number of repetitions: 16.5 vs 15.0, P = 0.038) but the effect was similar to that of the MVPA reference only. Meeting all three 24 h movement guidelines was not associated with measures of fitness in this sample. Meeting the MVPA recommendation was associated with greater aerobic fitness and muscle endurance.

CONCLUSIONS

In order to enhance children's physical fitness, public health recommendations should primarily target MVPA.

Fundamental Movement Skills and Accelerometer-Measured Physical Activity Levels during Early Childhood: A Systematic Review

Early childhood is a key period for children to begin developing and practicing fundamental movement skills (FMS), while aiming to perform sufficient physical activity (PA). This study reviews the current evidence for the levels of achievement in FMS and PA measured using accelerometers among 4-5-year-old children and examines differences by gender. This review was conducted using the PRISMA framework. Keyword searches were conducted in Pubmed, Medline, Google Scholar and SPORTDiscus. Inclusion criteria included age: 4-5 years old; FMS measurement: Test of Gross Motor Development 2 and 3; PA measurement: objective methods; balance measurement: static single limb; study design: cross-sectional observational/descriptive, randomised control trials, intervention studies; language: English. Twenty-eight articles from twenty-one countries met the inclusion criteria and were split into either FMS and PA articles (n = 10) or balance articles (n = 18). Three articles showed children achieving 60 min of moderate to vigorous PA per day, two articles demonstrated significant differences between girls' and boys' performance of locomotor skills and five reported locomotor skills to be more proficient than object control skills at this age for both genders. Balance was measured in time (n = 12), points score (n = 3) or biomechanical variables (n = 3), displaying heterogeneity of not only measurement but also outcomes within these data, with static single limb balance held between 6.67 to 87.6 s within the articles. Four articles reported girls to have better balance than boys. There is little conclusive evidence of the current levels for FMS, PA and balance achievement in young children 4-5 years of age. The academic literature consistently reports low levels of FMS competence and mixed evidence for PA levels. Inconsistencies lie in balance measurement methodology, with broad-ranging outcomes of both low and high achievement at 4-5 years old. Further research is required to focus on increasing practice opportunities for children to improve their FMS, increase PA levels and establish sufficient balance ability. Consistent and comparable outcomes during early childhood through more homogenous methodologies are warranted.

Correlates of Meeting the Physical Activity, Sedentary Behavior, and Sleep Guidelines for the Early Years among Belgian Preschool Children: The ToyBox-Study

Physical activity, sedentary behavior, and sleep guidelines for preschool children were already established and integrated into the 24 h movement behavior guidelines in 2017. The aim of the current study was to investigate correlates of meeting or not meeting the physical activity, sedentary behavior, and sleep guidelines in Belgian preschool children. In total, 595 preschool children (53.3% boys, 46.7% girls, mean age: 4.2 years) provided complete data for the three behaviors and potentially associated correlates. Physical activity was objectively measured with accelerometers. Screen time, sleep duration, and correlates were reported by parents with the use of a questionnaire. Backward logistic regression was used to identify factors associated with meeting all guidelines for weekdays and weekend days. In the final model, older preschoolers (OR = 1.89), having a normal weight compared to being underweight (OR = 0.30), having parents that do not watch a lot of television (OR = 0.99), and having a father that attained higher education (OR = 1.91) were associated with meeting all guidelines on weekdays. For weekend days, a significant association was found for attending a sports club (OR = 1.08). Overall, only a few factors were associated with meeting the guidelines. A more comprehensive measurement of preschool children’s potential correlates of physical activity, sedentary behavior, and sleep is warranted.

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.

Minimum accelerometer wear-time for reliable estimates of physical activity and sedentary behaviour of people receiving haemodialysis

BACKGROUND

Low levels of physical activity are implicated in low life expectancies of people receiving maintenance haemodialysis. Accelerometers are increasingly being used to quantify activity behaviours of this population but guidance to quality-assure such data is lacking. The objective of this study was to provide data processing and reduction recommendations to ensure accelerometer-derived outcomes are sufficiently reliable for interpretative analysis.

METHODS

Seventy people receiving maintenance haemodialysis (age 55.9 ± 15.7 years, 34% women, 23% diabetic) from a single outpatient renal unit volunteered for the study. Participants wore Actigraph GT3x and ActivPAL monitors during waking hours over seven days. Reliability of accelerometer output (normalised to wear-time) was assessed via intraclass correlation coefficient (ICC). The Spearman-Brown prophecy formula was subsequently applied to the ICCs to derive the minimum required accelerometer wear-time for each behavioural outcome.

RESULTS

Monitor wear compliance was greater on dialysis compared to non-dialysis days (90% v 77%). Participants were significantly more active on non-dialysis days compared to dialysis days but there were no significant differences in estimated behaviours between days within the same condition. Average measure ICCs for all accelerometer outcomes were high (range 0.76-0.96). Computations indicated that habitual physical activity and sedentary behaviour could be estimated with a minimum reliability level of 0.80 from one dialysis day and two non-dialysis days, and at least eight hours monitor wear per day. Applying this rubric allowed 90% of participant data to be retained for further analysis.

CONCLUSIONS

Regardless of accelerometer, one dialysis and two non-dialysis days data with a minimum of eight hours wear each day should enable habitual activity of people receiving maintenance haemodialysis to be characterised with acceptable reliability. These recommendations reconcile the tension between wear-time criteria stringency and retention of an adequately representative sample.

Proportion of Japanese primary school children meeting recommendations for 24-h movement guidelines and associations with weight status

BACKGROUND

24-h movement guidelines were recently developed to improve both the present and future health of children. The purpose of the present study was to evaluate adherence to the three recommendations strongly associated with health in 24-h movement guidelines and their relationship with weight status (overweight/obesity or underweight) in Japanese primary school children.

METHODS

This cross-sectional study was based on 902 children. Weight status according to measured body mass index (BMI) was classified by the WHO growth reference. Meeting the 24-h movement guidelines was defined as: 9-11 h/night of sleep, ≤2 h/day of screen time, and at least 60 min/day of moderate-to-vigorous physical activity (MVPA).

RESULTS

The prevalence of children meeting the all three recommendations was 10.5% and 13.2% met none of the three recommendations. Children meeting all three behaviors recommendation, screen time and MVPA or sleep recommendations, or only screen time recommendation had lower odds ratios adjusted for age, gender and socioeconomic status of each school for overweight/obesity compared to children meeting none of the 3 recommendations.

CONCLUSIONS

The screen time recommendation or combinations including screen time recommendation were associated with overweight/obesity. On the other hand, none of the recommendations was associated with underweight.

Understanding physical activity and sedentary behaviour among preschool-aged children in Singapore: a mixed-methods approach

OBJECTIVES

This study investigated physical activity (PA) and sedentary behaviour (SB) among preschool-aged children in Singapore and potential correlates at multiple levels of the socioecological model from in-school and out-of-school settings.

DESIGN

A cross-sectional study using a mixed-methods approach.

PARTICIPANTS

Parent-child dyads from six preschools in Singapore.

METHODS

PA and SB of children (n=72) were quantified using wrist-worn accelerometers for seven consecutive days. Three focus group discussions (FGDs) among 12 teachers explored diverse influences on children's activities, and System for Observing Play and Leisure Activity in Youth (SOPLAY) assessed PA environment and children's activity levels at preschools. Seventy-three parents completed questionnaires on home and neighbourhood factors influencing children's PA and SB. Descriptive analyses of quantitative data and thematic analysis of FGDs were performed.

RESULTS

Based on accelerometry, children (4.4±1.1 years) spent a median of 7.8 (IQR 6.4-9.0) hours/day in SB, and 0.5 (0.3-0.8) hours/day in moderate-to-vigorous physical activity (MVPA). MVPA was similar throughout the week, and SB was slightly higher on non-school days. In preschools, SOPLAY showed more children engaging in MVPA outdoors (34.0%) than indoors (7.7%), and absence of portable active play equipment. FGDs revealed issues that could restrict active time at preschool, including academic requirements of the central curriculum and its local implementation. The teachers had varying knowledge about PA guidelines and perceived that the children were sufficiently active. In out-of-school settings, parents reported that their children rarely used outdoor facilities for active play and spent little time in active travel. Few children (23.5%) participated in extracurricular sports, but most (94.5%) reported watching screens for 1.5 (0.5-3.0) hours/day.

CONCLUSION

MVPA was low and SB was high in preschool-aged children in an urban Asian setting. We identified diverse in-school and out-of-school correlates of PA and SB that should be taken into account in health promotion strategies.

Reproducibility of objectively measured physical activity: Reconsideration needed

Reliability of accelerometer-determined physical activity (PA), and thus the required length of a monitoring period, appears to depend on the analytic approach used for its calculation. We compared reliability of objectively measured PA using different resolution of data in a sample of 221 Norwegian 2-6-year-old children providing 2-3 valid 14-day periods of accelerometer monitoring (ActiGraph GT3X+) during September-October, January-February, and May-June 2015-2016. Reliability (intra-class correlation [ICC]) was measured for 1-14 days of monitoring across the measurement periods using linear mixed effect modelling. These results were compared to reliability estimated using different resolution of data using the Spearman-Brown formula. The measured reliability improved only marginally with increased monitoring length and levelled off after 5-6 days. Estimated reliability differed substantially when derived from different resolution of data: 3.9-5.4, 6.7-9.2, 13.4-26.7 and 26.3-87.7 days of monitoring was required to achieve an ICC = 0.80 using an hour-by-hour, a day-by-day, a week-by-week and a period-by-period approach, respectively. Reliability could not be correctly estimated from any single resolution of data. We conclude that reconsideration is needed with regard to how reproducibility of objectively measured PA is analysed and interpreted.

Associations between Daily Step Counts and Physical Fitness in Preschool Children

Purpose: To investigate the relationships between daily step counts and physical fitness in preschool children. Methods: Preschoolers’ step counts were assessed by ActiGraph accelerometers consecutively for seven days. Physical fitness was assessed by a 20 m shuttle run test (cardiorespiratory fitness), the handgrip and standing long jump tests (musculoskeletal fitness), and the 2 × 10 m shuttle run test (speed/agility). A composite score was created from the mean of the standardized values of all physical fitness tests. Results: A total of 301 preschoolers (134 girls, mean age 57.40 ± 5.47 months; 167 boys, mean age 58.10 ± 5.34 months) were included in the final analysis. Compared with the lowest tertile, boys and girls in the highest tertile of step counts achieved high physical fitness with odds ratio (OR) being 5.39 (95% CI = 1.65–17.59) and 4.42 (95% CI = 1.30–14.99), respectively, after adjusting for confounders. Meanwhile, a relationship was observed for each 1000 steps/day increment being associated with 43% (OR = 1.43, 95% CI = 1.10–1.85) and 62% (OR = 1.62, 95% CI = 1.20–2.19) increment for high physical fitness in boys and girls, respectively. In addition, significant non-linear relationship was observed between daily steps and physical fitness in boys, which indicated that accumulated 8000 steps/day was associated with the highest ratio to achieve high physical fitness. Conclusions: Positive relationships between step counts and physical fitness were observed in preschool children, and the relationships were strongest for those who accumulated 8000 steps/day in boys. To confirm the findings in this study, well-designed and large-scale longitudinal studies are needed in the future.

Accelerometer-derived physical activity estimation in preschoolers - comparison of cut-point sets incorporating the vector magnitude vs the vertical axis

Background

ActiGraph accelerometers are a widely used tool to objectively measure physical activity (PA) behavior in young children and several validated cut-point sets exist to estimate time spent in different PA intensities (sedentary time, light PA, moderate-to-vigorous PA). Applying different cut-point sets leads to large and meaningful differences in results. So far, only cut-point sets validated for the vertical axis have been compared and only the influence on time spent in moderate-to-vigorous PA has been analyzed.

Methods

A range of validated cut-point sets with their respective epoch length was applied to analyze cross-sectional data of the Swiss Preschoolers’ Health Study (SPLASHY): 1) Vertical axis in combination with an epoch length of 15 s (VA-15), 2) Vertical axis in combination with an epoch length of 60 s (VA-60) and 3) Vector magnitude in combination with an epoch length of 60 s (VM-60). PA was measured for eight consecutive days using ActiGraph accelerometers (wGT3X-BT). Three days were required to be included in the analysis (minimum two weekdays and one weekend-day with at least ten hours recording per day).

Results

Four hundred forty-five preschoolers (mean age 3.9 ± 0.5 years; 46% girls) had valid accelerometer measurements. A longer epoch (VA-60 vs VA-15) resulted in 2% less sedentary time (ST), 18% more light PA (LPA) and 51% less moderate-to-vigorous PA (MVPA); using the vector magnitude compared to the vertical axis (VM-60 vs VA-60) resulted in 34% less ST, 27% more LPA and 63% more MVPA (all p ≤ 0.001). Comparing all three sets of cut-points, ST ranged from 4.0 to 6.2 h, LPA from 5.1 to 7.6 h and MVPA from 0.8 to 1.6 h.

Conclusions

Estimated time spent in different PA intensities was strongly influenced by the choice of cut-point sets. Both, axis selection and epoch length need to be considered when comparing different studies especially when they relate PA behavior to health. The differences in the prevalence of children fulfilling PA guidelines highlight the relevance of these findings.

Trial registration

Current Controlled Trials ISRCTN41045021 (date of registration: 21.03.2014).

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6837-7) contains supplementary material, which is available to authorized users.

Effectiveness of interventions to increase physical activity in individuals with intellectual disabilities: a systematic review of randomised controlled trials

BACKGROUND

People with intellectual disabilities (ID) often do not meet recommended guidelines for physical activity. The aim of this study was to systematically review available evidence that evaluated the effectiveness of interventions to increase physical activity in individuals with ID.

METHOD

Five electronic databases (MEDLINE, CINAHL, EMBASE, SPORTDiscus and Cochrane Central Register of Controlled Trials) were searched from inception of the database to July 2017 to identify randomised controlled trials that evaluated the effectiveness of interventions to improve physical activity among people with ID. Trials were included if they measured at least one objective measure of physical activity. Quality appraisal was completed by two independent reviewers using the Cochrane Risk of Bias Tool. The magnitude of treatment effect was estimated for each intervention by calculating the standardised mean difference (SMD) and associated 95% confidence interval.

RESULTS

Nine randomised controlled trials (976 participants, 501 women, age range 9 months to 83 years) were included. Four trials evaluated unimodal interventions and five trials evaluated multimodal health promotion programmes based on using supportive environments to enable sustained behavioural changes in physical activity. None of the trials were rated as low risk of bias as all had at least one item on the Cochrane Risk of Bias Tool that was considered to be high risk. No trials were able to implement participant blinding. Three trials found statistically significant beneficial effects of interventions for increasing physical activity. Results showed that a 10-week progressive resistance training programme led to maintenance of physical activity levels at 24 weeks in adolescents with Down syndrome (SMD 0.78, 95% CI 0.17 to 1.40). Additionally, a 12- to 16-month multicomponent diet and physical activity programme produced improvement in physical activity at programme completion in adults with ID (reported effect size of 0.29). Finally, an 8-month physical activity and fitness programme increased physical activity at 8 months in adults with ID (SMD 0.91, 95% CI 0.20 to 1.60). Findings regarding other interventions were inconclusive with small effects that were not statistically significant.

CONCLUSIONS

There is inconsistent evidence of the effects of interventions for improving physical activity levels in individuals with ID. A progressive resistance training programme was found to maintain physical activity levels in adolescents with Down syndrome, while a multicomponent diet and physical activity programme and a physical activity and fitness programme were found to improve physical activity levels in adults with ID. Future trials using rigorous research designs are required to confirm these findings and establish whether other interventions designed to increase physical activity in people with ID are effective.

Effects of a combined physical and psychosocial training for children with cancer: a randomized controlled trial

BACKGROUND

Physical fitness and psychosocial function is often reduced in children during or shortly after cancer treatment. This study evaluates the effect of a combined physical exercise and psychosocial intervention on cardiorespiratory fitness, muscle strength, body composition, psychosocial function and health-related quality of life (HrQoL). In addition, intervention mediators, applicability and adherence were examined.

METHODS

This multicenter randomized controlled trial included 68 children with cancer [mean age 13.2 (SD: 3.1) years; 54% male] during treatment or within 12-months post-treatment. The 12-week intervention consisted of 24 individual physical exercise sessions supervised by a physiotherapist, and 6 psychosocial training sessions for children and 2 for parents. Physical fitness and psychosocial function were assessed at baseline, directly post-intervention and at 12 months' post-baseline. Generalized estimating equations were used to simultaneously assess intervention effects at short and long-term. Additionally, we evaluated within-group differences over time. Potential physical and psychosocial mediators in the intervention effect on HrQoL were examined using the product-of-coefficient test. Applicability and adherence were assessed by trainer-report.

RESULTS

This study was able to compare 26 children who received the study intervention, with 33 children who received usual care. No significant differences in the effects of the intervention were found on physical fitness and psychosocial function at short-term. At 12-months follow-up, significantly larger improvements in lower body muscle strength (β = 56.5 Newton; 95% CI: 8.5; 104.5) were found in the intervention group when compared to the control group. Within-group changes showed significant improvements over time in HrQoL and bone density in both groups. Intervention effects on HrQoL were not significantly mediated by physical fitness and psychological function. Intervention applicability was satisfactory with an average session attendance of 67% and 22% dropout (mainly due to disease recurrence).

CONCLUSIONS

This 12-week physical exercise and psychosocial training intervention for children with cancer was applicable and showed satisfactory adherence. We found no significant between-group differences in effect, except for a significant improvement in lower body muscle strength at long-term in the intervention group compared to the control group. Yet, both the intervention and the control group showed improvements in bone mineral density and HrQoL over time.

TRIAL REGISTRATION

The trial was registered at the Dutch Trial Registry ( NTR1531 ). Registered 12 November 2008.

Kindergarten: Producer or Reducer of Inequality Regarding Physical Activity Levels of Preschool Children

Several studies have shown that children have sub-optimal physical activity levels. Since preschool children (4-6 years-old) spend most of their time awake in kindergarten on weekdays, physical activity level at kindergarten is crucial. The study examines preschool children's physical activity level at kindergarten. Preschool children's activity level at kindergarten is also investigated related to activity level at leisure, gender, and mothers' education level, income, and age. Two hundred and forty four children (125 boys and 119 girls) supplied valid accelerometer data, and mothers' education level, income, and age were measured using a questionnaire. One-way ANOVA and linear regression were utilized as statistical analyses. The results demonstrated that physical activity level during kindergarten is the main contributor to preschool children's physical activity level on weekdays. Furthermore, boys were more active than girls, and preschool children's physical activity level at both leisure and at kindergarten were not associated with mothers' age, education level, or income. However, a positive association was found between physical activity level at leisure and physical activity level at kindergarten, in which physical activity level at kindergarten increases when physical activity level at leisure increases. Physical activity level was also significantly different between kindergartens. The study indicated that kindergartens increase inequality according to physical activity level among preschool children-contributing to creating differences according to low-active and high-active children.

"Oh oobe doo, I wanna be like you" associations between physical activity of preschool staff and preschool children

OBJECTIVE

Physical activity contributes to prevent serious diseases and ailments, and previous research indicates that lifestyle habits are likely to track from early childhood to adulthood. 90% of Norwegian children aged 1-5 are enrolled in preschools, and preschool staff can play an important role in children's activity levels. This study's aim was to identify whether any associations exist between preschool staff's characteristics (initiative, participation, attitudes, and activity levels) and children's activity in preschool.

METHOD

289 children aged 4-6 and 72 preschool staff from 13 randomly selected preschools in a region of Nord-Troendelag, Norway, were enrolled in the study. All participants wore an Actigraph accelerometer for seven consecutive days. Questionnaires were also utilized to identify correlates between preschool staff's attitudes and initiative in relation to children's physical activity, in addition to their participation in children's physical activity. A multilevel analysis, the linear mixed model (LMM), was used to elucidate associations between preschool staff and children's activity levels.

RESULTS

A significant association was found between preschool staff's average activity levels during preschool hours and children's corresponding activity levels during preschool hours (t = 2.57; p = 0.021; f2 = 0.013). There were, however, no significant associations identified between the attitudes (t = -0.44; p = 0.67), initiative (t = -0.14; p = 0.89), and participation (t = 0.66; p = 0.52) variables among preschool staff and children's activity levels during preschool hours.

CONCLUSION

The study demonstrated that a significant association exists between preschool staff's aggregated activity levels and 4-6-year-olds' individual activity levels. However, an observational study is requisite in order to determine whether the association is based on preschool staff's impact on children's physical activity or if it is the children that affect the preschool staff's activity levels, or a combination thereof.

Compliance with 24-h Movement Behaviour Guidelines among Belgian Pre-School Children: The ToyBox-Study

The 24-h day-containing physical activity, sedentary behaviour and sleep-in pre-school children has not yet been extensively investigated. The aim of the current study was to investigate pre-schoolers' compliance with the 24-h movement behaviour guidelines (i.e., three hours/day total physical activity, a maximum of one hour/day of screen time and 10⁻13 h sleep/night). In total, 595 pre-schoolers (53.3% boys, mean age: 4.2 years) provided complete data for the three behaviours. Physical activity was objectively measured with accelerometers, while screen time and sleep were parent-reported through questionnaires. The proportion of pre-schoolers complying with the 24-h movement behaviour guidelines was calculated on weekdays and on weekend days. Low compliance rates were found: 10.1% on weekdays and only 4.3% on weekend days. The majority of pre-schoolers complied with the sleep duration guidelines (>90% on weekdays and weekend days), followed by the screen time guidelines (61% on weekdays and 28% on weekend days). The lowest compliance rates were found for physical activity (<20% on weekdays and weekend days). Overall, low percentages of pre-schoolers complying with the 24-h movement behaviour guidelines were found, and the lowest compliance was found for physical activity.

Association between age at onset of independent walking and objectively measured sedentary behavior is mediated by moderate-to-vigorous physical activity in primary school children

OBJECTIVE

Age at onset of walking has been shown as an early predictor of physical activity in infants and children. However, little is known about whether age at onset of walking may predict sedentary behavior (SB). The aim of the present study was to examine the association between the timing of onset of walking and objectively measured SB, and whether this association is mediated by moderate-to-vigorous physical activity (MVPA) in children.

METHODS

The subjects were 388 elementary school children aged 6-12 years. Current weight and height data were collected. Birth weight and the age in months the child first walked independently were reported based on the parents' recall. Children's SB and physical activity were objectively measured using a triaxial accelerometer (Active style Pro HJA-350IT, OMRON). The following summary outcome variables were derived from accelerometer data: Time (min/day) spent in SB (≤1.5 metabolic equivalents [METs]) and MVPA (≥3.0 METs).

RESULTS

The mean ± SD time (min/day) spent in sedentary was 376 ± 62 and MVPA was 67.6 ± 20.8. Multiple linear regression analyses revealed that a later age at independent walking was associated with increased time spent in SB (β = 0.15, P < 0.001) and decreased time spent in MVPA (β = -0. 18, P < 0.001) after adjusting for gender, birth weight, current age, body weight, schools, and time spent wearing the accelerometer. When MVPA was introduced as a covariate in the model predicting SB, the association between the age at independent walking and time spent in SB was completely attenuated (β = 0.04, P = 0.215), while MVPA was significantly associated with SB (β = -0.61, P < 0.001).

CONCLUSIONS

Our results indicate that infants who walked at a later age spent more time in SB in childhood, and this association is mediated by MVPA. Appropriate interventions which focus on increasing MVPA and thereby reducing SB may be beneficial in infants who demonstrate a later age at onset of independent walking.

Not all sedentary behaviour is equal: Children's adiposity and sedentary behaviour volumes, patterns and types

OBJECTIVE

The importance of different constructs of sedentary behaviours in relation to childhood obesity is uncertain. Thus, this study aimed to investigate relationships between volume, patterns and types of sedentary behaviour and adiposity in children.

METHODS

A case-control study was undertaken involving 234 children aged 10-13years who were either of a healthy-weight (74 boys, 56 girls) or classified as obese (56 boys, 48 girls). Percent body fat (by dual-energy X-ray absorptiometry) and waist-to-height ratio were assessed. Time, type (television, videogame, computer, eating, passive transport) and bout length of sedentary behaviours were measured using accelerometry and the Multimedia Activity Recall for Children and Adolescents. Time use (total daily energy expenditure, sleep, physical activity), age, household income and Tanner stage were covariates in sex-stratified partial least squares analyses.

RESULTS

Daily energy expenditure and income were negatively associated with adiposity for both sexes. Television time was consistently positively associated with adiposity. In boys only, prolonged bouts of sedentary behaviour and time spent playing video games/computer were positively linked with adiposity. Non-screen sedentary behaviour was negatively associated with adiposity in girls. Independent of total energy expenditure, total sedentary time was only inconsistently associated with fatness.

CONCLUSIONS

These data suggest that (1) characteristics of sedentary time other than duration are associated with adiposity in children, and (2) associations may be sex-specific.

Parental physical activity is associated with objectively measured physical activity in young children in a sex-specific manner: the GECKO Drenthe cohort

BACKGROUND

Physical activity (PA) is important in combating childhood obesity. Parents, and thus parental PA, could influence PA in young children. We examined whether the time spent at different intensities of PA and the type of parental PA are associated with the PA of children aged 4-7 years, and whether the associations between child-parent pairs were sex-specific.

METHODS

All the participants were recruited from the Groningen Expert Center for Kids with Obesity (GECKO) birth cohort (babies born between 1 April 2006 and 1 April 2007 in Drenthe province, the Netherlands) and were aged 4-7 years during measurement. PA in children was measured using the ActiGraph GT3X (worn at least 3 days, ≥10 h per day). PA in parents was assessed using the validated SQUASH questionnaire.

RESULTS

Of the N = 1146 children with valid ActiGraph data and 838 mothers and 814 fathers with valid questionnaire data, 623 child-parent pairs with complete data were analysed. More leisure time PA in mothers was associated with more time spent in moderate-to-vigorous PA (MVPA) in children (Spearman r = 0.079, P < .05). Maternal PA was significantly related to PA in girls, but not boys. More time spent in maternal vigorous PA, in sports activity, and leisure time PA, were all related to higher MVPA in girls (Spearman r = 0.159, r = 0.133 and r = 0.127 respectively, Pall < .05). In fathers, PA levels were predominantly related to PA in sons. High MVPA in fathers was also related to high MVPA in sons (r = 0.132, P < 0.5). Spending more time in light PA was related to more sedentary time and less time in MVPA in sons.

CONCLUSIONS

Higher PA in mothers, for instance in leisure activities, is related to higher PA in daughters, and more active fathers are related to more active sons. To support PA in young children, interventions could focus on the PA of the parent of the same sex as the child. Special attention may be needed for families where the parents have sedentary jobs, as children from these families seem to adopt more sedentary behaviour.

A School- and Home-Based Intervention to Improve Adolescents' Physical Activity and Healthy Eating: A Pilot Study

This study evaluated feasibility, acceptability, and preliminary efficacy of a 12-week Guys/Girls Opt for Activities for Life (GOAL) intervention on 10- to 13-year-old adolescents' body mass index (BMI), percent body fat, physical activity (PA), diet quality, and psychosocial perceptions related to PA and healthy eating. Parent-adolescent dyads from two schools were enrolled. Schools were assigned to either GOAL (38 dyads) or control (43 dyads) condition. The intervention included an after-school club for adolescents 2 days/week, parent-adolescent dyad meeting, and parent Facebook group. Intervention adolescents had greater autonomous motivation for PA and self-efficacy for healthy eating than control adolescents (both p < .05). Although between-group differences were not significant, close-to-moderate effect sizes resulted for accelerometer-measured moderate-to-vigorous PA and diet quality measured via 24-hr dietary recall (d = .46 and .44, respectively). A trivial effect size occurred for percent body fat (d = -.10). No differences emerged for BMI. Efficacy testing with a larger sample may be warranted.

Accelerometry to measure physical activity in toddlers: Determination of wear time requirements for a reliable estimate of physical activity

Accelerometry is widely used to evaluate physical activity in toddlers however recommendations regarding wear time are needed to understand physical activity behaviours in this age group. This study aimed to determine the minimum wear time to reliably evaluate physical activity in toddlers. Children from the 3D Birth Cohort (n = 255, 49.8% boys, 2.1 ± 0.2 years) were asked to wear an accelerometer (GT3X+, ActiGraph) for 7 days. Physical activity was expressed in active time (min/day) and counts per minute (CPM). Single day intraclass correlation coefficients (ICCs) were calculated to assess the effect of varying minimal wear time on reliability estimates. The Spearman-Brown formula was used to determine wear time required to achieve reliability levels of 70%, 80% and 90%. For active time, a reliability of 72.1% was achieved with wearing the accelerometer for ≥ 4 days of ≥ 6 h, which comprised 85.9% of the sample. For CPM, ≥ 4 days of ≥ 6 h provided a reliability of 74.7% and comprised 85.9% of the children. Results differed slightly when girls and boys were analysed separately, but restricting analyses to children with a weekend day did not. In summary, a minimum of 4 days with ≥ 6 h of accelerometry data provides a reliable estimate of physical activity in 2-year toddlers.

Reproducibility of domain-specific physical activity over two seasons in children

BACKGROUND

Knowledge of the reproducibility of domain-specific accelerometer-determined physical activity (PA) estimates are a prerequisite to conduct high-quality epidemiological studies. The aim of this study was to determine the reproducibility of objectively measured PA level in children during school hours, afternoon hours, weekdays, weekend days, and total leisure time over two different seasons.

METHODS

Six hundred seventy six children from the Active Smarter Kids study conducted in Sogn og Fjordane, Norway, were monitored for 7 days by accelerometry (ActiGraph GT3X+) during January-February and April-May 2015. Reproducibility was estimated week-by-week using intra-class correlation (ICC) and Bland-Altman plots with 95% limits of agreement (LoA).

RESULTS

When controlling for season, reliability (ICC) was 0.51-0.66 for a 7-day week, 0.55-0.64 for weekdays, 0.11-0.43 for weekend days, 0.57-0.63 for school hours, 0.42-0.53 for afternoon hours, and 0.42-0.61 for total leisure time. LoA across models approximated a factor of 1.3-2.5 standard deviations of the sample PA levels. 3-6 weeks of monitoring were required to achieve a reliability of 0.80 across all domains but weekend days, which required 5-32 weeks.

CONCLUSION

Reproducibility of PA during leisure time and weekend days were lower than for school hours and weekdays, and estimates were lower when analyzed using a week-by-week approach over different seasons compared to previous studies relying on a single short monitoring period. To avoid type 2-errors, researchers should consider increasing the monitoring period beyond a single 7-day period in future studies.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT021324947 . Registered on 7 April 2014.

The Daily Mile makes primary school children more active, less sedentary and improves their fitness and body composition: a quasi-experimental pilot study

BACKGROUND

The Daily Mile is a physical activity programme made popular by a school in Stirling, Scotland. It is promoted by the Scottish Government and is growing in popularity nationally and internationally. The aim is that each day, during class time, pupils run or walk outside for 15 min (~1 mile) at a self-selected pace. It is anecdotally reported to have a number of physiological benefits including increased physical activity, reduced sedentary behaviour, increased fitness and improved body composition. This study aimed to investigate these reports.

METHODS

We conducted a quasi-experimental repeated measures pilot study in two primary schools in the Stirling Council area: one school with, and one without, intention to introduce the Daily Mile. Pupils at the control school followed their usual curriculum. Of the 504 children attending the schools, 391 children in primary classes 1-7 (age 4-12 years) at the baseline assessment took part. The follow-up assessment was in the same academic year. Outcomes were accelerometer-assessed average daily moderate to vigorous intensity physical activity (MVPA) and average daily sedentary behaviour, 20-m shuttle run fitness test performance and adiposity assessed by the sum of skinfolds at four sites. Valid data at both time points were collected for 118, 118, 357 and 327 children, respectively, for each outcome.

RESULTS

After correction for age and gender, significant improvements were observed in the intervention school relative to the control school for MVPA, sedentary time, fitness and body composition. For MVPA, a relative increase of 9.1 min per day (95% confidence interval or 95%CI 5.1-13.2 min, standardised mean difference SMD = 0.407, p = 0.027) was observed. For sedentary time, there was a relative decrease of 18.2 min per day (10.7-25.7 min, SMD = 0.437, p = 0.017). For the shuttle run, there was a relative increase of 39.1 m (21.9-56.3, SMD = 0.236, p = 0.037). For the skinfolds, there was a relative decrease of 1.4 mm (0.8-2.0 mm, SMD = 0.246, p = 0.036). Similar results were obtained when a correction for socioeconomic groupings was included.

CONCLUSIONS

The findings show that in primary school children, the Daily Mile intervention is effective at increasing levels of MVPA, reducing sedentary time, increasing physical fitness and improving body composition. These findings have relevance for teachers, policymakers, public health practitioners, and health researchers.