Methodological considerations in using accelerometers to assess habitual physical activity in children aged 0-5 years

Comparing Hip, Wrist and Ankle-Worn ActiGraph Accelerometers for Measuring Physical Activity in Toddlers

BACKGROUND

Understanding the relationships among accelerometer placements and the agreements between cut points is essential to enhancing the accuracy of physical activity measurement for toddlers. This study aimed to compare the magnitudes and relationships of activity counts from hip, wrist and ankle ActiGraph GT9X accelerometers in toddlers and to assess the agreement between age-specific cut points at group and individual levels.

METHODS

Accelerometer data were collected from nine toddlers (three girls, 22.2 ± 6.1 months) during 12 weekly 20-min free-play sessions. Activity counts were downloaded using specific epoch lengths and filters according to the studies validating the cut points. One-way repeated ANOVAs were used to compare the activity counts per 15 s across placements. Interplacement relationships were examined using Spearman's rank correlation coefficients. Agreements were assessed with Bland-Altman plots between three sets of hip cut points and one wrist cut point. Ankle data were not analysed because of a lack of validated cut points.

RESULTS

The wrist placement yielded the highest counts, followed by ankle and hip. The correlation coefficient was strongest between hip and ankle vector magnitude counts (rs = 0.88), whereas relatively weaker between wrist and hip (rs = 0.65) and wrist and ankle (rs = 0.60). The Bland-Altman plots indicated that time estimates for sedentary, light and moderate-to-vigorous physical activity were significantly different between most cut points. At the individual level, considerable variations in interplacement correlations and physical activity time estimates were observed.

CONCLUSION

The strong correlation between hip and ankle activity counts suggests that the ankle could be a feasible sensor-wearing location. The moderate correlation between wrist and hip suggests that multiple accelerometers may be needed to enhance accuracy. Discrepancies across cut points indicate that more research is needed to validate cut points for accurately measuring physical activity in toddlers, especially considering individual differences in movement behaviours.

Exploring 24-Hour Movement Behaviors in Early Years: Findings From the SUNRISE Pilot Study in Tunisia

PURPOSE

The International Study of Movement Behaviors in the Early Years (SUNRISE) was conducted in Tunisia to assess the proportion of preschoolers who met the World Health Organization guidelines for physical activity, sedentary behavior, and sleep. The study also evaluated the feasibility of the methods for the SUNRISE study.

METHODS

Five kindergartens were recruited from urban and rural areas in Tunisia. Physical activity and sleep duration were assessed using a waist-worn ActiGraph. Screen time and sleep quality were assessed via an interview-administered parent questionnaire. The NIH Toolbox was used.

RESULTS

A total of 112 preschoolers were assessed (50 boys, age = 4.1 [0.58]). Only 18% of children met all recommendations of the World Health Organization guidelines, while 53% met the sedentary screen time (in minutes per day), and 41% met physical activity recommendation (in minutes per day). Eighty-one percent of children met the sleep duration recommendation (in minutes per day). There was good compliance with the ActiGraph protocol.

CONCLUSIONS

This pilot study provided important insights into the feasibility of the study and the movement behaviors of Tunisian preschool children. The results suggest there is a need to promote healthy levels of physical activity and sedentary screen time in children, which should be a priority in public health initiatives, including preschool curricula, in Tunisia.

Socioeconomic disparities in organized sports participation and physical activity among a population based sample of preschool children: a cross-sectional study

BACKGROUND

Encouraging children to participate in organized sports could increase physical activity and may promote lifelong healthy habits. There are socioeconomic disparities in organized sports participation in school-aged children and adolescents. However, it is not known if these socioeconomic disparities exist among preschool-aged children.

OBJECTIVE

The purpose of this study was to examine (i) the association between organized sports participation and physical activity (ii) differences in organized sports participation according to socioeconomic status among preschool children.

METHODS

The study sample was a representative population-based sample of 2935 preschool-aged children (48.3% girls; age range 2-6 years) in Stockholm, Sweden. Physical activity was measured using GT3X + accelerometers for one week at the fall of 2020 or in the spring of 2021 and organized sports participation was parent-reported. Parental education and a Stockholm based socioeconomic index were used to examine socioeconomic disparities. Linear regression was used to estimate associations between organized sports participation and physical activity and multinomial logistic regression was used to estimate the differences in organized sports participation over parental education and neighborhood socioeconomic index.

RESULTS

The study population had a mean age of 4.5 years (SD = 0.9), consisted of 48.3% girls and spent in average 46.5 min (SD = 15.4) engaged in moderate to vigorous physical activity per day. Additionally, 1,658 children (56.5%) did not participate in organized sports. Participation in organized sports once a week or more was associated with a 2.8-min increase in average daily moderate to vigorous physical activity (95% CI; 1.56, 4.06), compared to not participating. Further, both living in a higher socioeconomic index area and higher parental education was associated with higher organized sports participation.

CONCLUSIONS

Participation in organized sports indicates a modest contribution to physical activity among preschool-aged children. However, participation in organized sports varies according to neighborhood socioeconomic index and parental education. These findings highlight the importance of targeting organized sport participation according to socioeconomic gradients, to moderate inequities in access and opportunity to organized sport.

Effects of a physical activity-enhanced curriculum on increasing physical activity and improving physical fitness in preschoolers: Study protocol for a cluster randomized controlled trial (KID-FIT study)

Objective

Physical activity (PA) is critical for healthy development in preschoolers, with long-lasting benefits that can affect later life. The World Health Organization (WHO) recommends that children aged 5-17 years should engage in 60 min of moderate-to-vigorous PA per day. However, physical inactivity in children is on the rise globally, with declines in PA starting at the age of 4 years. Increasing PA during early childhood is important to delay adiposity rebound, promote behavioral changes, improve physical fitness, and facilitate future PA engagement. However, limited evidence has been established on the effects of school-based PA interventions on preschoolers. This study examines the effects and sustainability of a preschool-based PA intervention on increasing PA, improving physical fitness and health in preschoolers, with the exercise dose benchmarked to the WHO PA guidelines.

Methods

This assessor-blinded, two-arm cluster randomized controlled trial will include 3300 preschoolers (aged 5-6 years) from 110 kindergartens in Hong Kong, China. Kindergartens will be randomized into intervention and control groups in a 1:1 ratio. The control kindergartens will continue their usual curriculum of ∼2.5 h PA/week, whereas preschoolers in the intervention kindergartens will engage in an additional 75-min game-based PA class twice per week (extra 2.5 h PA/week) over the preschool year. This multi-component intervention will also target parents, teachers, and the kindergarten environment to further encourage PA in preschoolers and their families. Objectively measured PA, cardiorespiratory fitness and other physical fitness components (muscle strength and power, agility, balance, flexibility, body composition), and psychological health will be examined at the start (0 month) and end (10 months) of the preschool year. Maintenance effects will be assessed after preschoolers' transition into primary school (16 months). Generalized estimating equations or other appropriate statistical models will be used to examine the treatment effects with adjustment for baseline values.

Study impact

This study will investigate the effects of a preschool-based PA intervention with PA dose benchmarked to the WHO recommendations on promoting PA, physical fitness, and health in preschoolers, and its sustainability after preschoolers' transition into primary education. The findings will raise public awareness on the importance of PA in young children, and will inform policy making to facilitate early childhood educational reforms to incorporate adequate PA into preschool curriculums to improve children's health in the long run.

Trial registration

ClinicalTrials.gov (NCT05521490).

Accelerometer Monitoring Duration for Reliable Estimates of Physical Activity, Sedentary Behavior, and Step Counts in Preschoolers

PURPOSE

This study aims to establish the reliability of accelerometer-based measurements for physical activity, sedentary behavior, and step counts in preschoolers and determine the optimal monitoring duration necessary for reliable data.

METHODS

The study analyzed data from 434 preschoolers (ages 3-5) who wore waist-worn ActiGraph wGT3X-BT accelerometers for 7 days as part of the Sunrise Study in Spain. Two-way mixed effects intraclass correlation coefficients were calculated for various combinations of daily wear time and number of valid days to assess reliability. The Spearman-Brown prophecy formula was applied to determine the required days to achieve reliability scores of 0.7, 0.8, and 0.9.

RESULTS

The findings showed that reliability improved with increased wear time, although intraclass correlation coefficients values were weaker around 7 to 9 hours per day. To achieve a reliability score of 0.7, moderate to vigorous physical activity required 3 to 4 days, light physical activity required 4 to 7 days, and sedentary behavior required 8 to 13 days. Steps per day required 7 to 9 days for a reliability score of 0.7, while other step outcomes needed 10 to 13 days.

CONCLUSION

The study provides evidence-based recommendations on the monitoring duration required for reliable estimates of physical activity, sedentary behavior, step counts, and sleep duration in preschoolers using accelerometers. These findings are crucial for researchers and practitioners aiming to accurately assess and promote physical activity in early childhood.

Geographic disparities in physical activity, sedentary behavior, sleep time, and gross motor skills in Nigerian preschoolers

Background

Adherence to physical activity guidelines is crucial for children's physical, social, and cognitive well-being. While previous research shows that about 77% of preschoolers meet the World Health Organization (WHO) physical activity guidelines, differences in outcomes based on geographic locations are unclear. This study examines disparities in physical activity, sedentary behavior, sleep, and gross motor skills between rural and urban preschoolers.

Methods

The study involved 131 healthy preschoolers (3.4 ± 0.8 years) from Lagos State, Nigeria. Participants wore ActiGraph GT3X+ accelerometers on their hips for at least 72 h per week. Socio-demographic data were collected using a parent-reported survey. Physical activity (light, moderate-vigorous) and sedentary time were measured using accelerometers, while gross motor skills were assessed using a modified version of the NIH Toolbox. Independent sample t-tests tested the difference between the two groups.

Results

No significant difference in sleep time (t = -0.22, p = 0.83) was found between urban and rural preschoolers. However, significant differences were observed in sedentary time (t = -3.49, p < 0.01, d = -0.67), light-intensity physical activity (LPA; t = 3.07, p < 0.01, d = 0.62), moderate-to vigorous-physical activity (MVPA; t = 4.77, p < 0.01, d = 0.91), and all gross motor skills (p < 0.05). Urban children exhibited more sedentary time and lower gross motor skill scores.

Conclusion

Rural preschoolers demonstrated higher physical activity levels and better gross motor skills than urban preschoolers. There is a pressing need for intervention programs to enhance physical activity and gross motor skills and reduce sedentary time among urban preschoolers.

Methodological Choices on 24-h Movement Behavior Assessment by Accelerometry: A Scoping Review

BACKGROUND

There are no reviews describing current measurement protocols and accelerometer processing decisions that are being used in 24-h MovBeh studies, across the lifespan. We aim to synthesise information on methods for assessing 24-h movement behaviors using accelerometry across all age groups.

MAIN BODY

PubMed, PsycINFO, SPORTDiscus, and EMBASE were searched until December 2022. Observational or intervention reports describing accelerometry methods in studies on combinations of movement behaviors, with a 24-h protocol across all ages, were included. This review included 102 studies: three studies in toddlers, 15 in preschoolers, 17 in children, 23 in adolescents and 44 in adults and older adults. The Actigraph GT3X was the most commonly used device; the majority of the included reports collected data for seven days, including three weekdays and one weekend day, with a ≥ 16 h/day per 24-h period for valid data. The criteria for non-wear time varied between ≥ 20 and  ≥ 90 min of consecutive zero counts, depending on the age group. The most common epoch used was 15 or 60 s for youth and adults, respectively. The choice of sleep algorithms and SB/PA cut-points, of the included reports, depended on age and the original validation/calibration study. To deal with non-compliant participants, exclusion of non-compliant participants from the analysis was most frequently used. Most studies used diaries/logs to complement the accelerometer data.

CONCLUSIONS

Accelerometer protocols and methodological decisions varied considerably between reports. Therefore, consensus on methodological decisions is needed to improve precision and comparability between studies, which is challenging given the complexity of the procedures, the number of available brands and types of accelerometers, and the plethora of programming options.

Physical activity and screen time: prospective associations with child emotional and behavioral well-being during the COVID pandemic

BACKGROUND

Physical activity (PA) and screen time (ST) were examined longitudinally over 66 months to evaluate their association with child emotional and behavioral health during the early months of the COVID pandemic.

METHODS

Data are from 288 racially/ethnically diverse low-income children ages 2-4 years enrolled in the NET- Works studies (2012-2020). Baseline, 12-, 24-, 36- and 66-month measures of PA and ST were collected before the onset of the COVID pandemic. During the pandemic shutdown, parents completed a measure of their child's emotional and behavioral health (Strengths and Difficulties Questionnaire, SDQ). Longitudinal associations were examined between children's previous five-year PA and ST patterns and emotional and behavioral problems during the COVID shutdown.

RESULTS

Children whose objectively measured PA met recommendations at all five visits during the previous 66 months had poorer emotional and behavioral health, compared to less consistently active children (SDQ Emotions 0.91 points higher, 95% CI = 0.22, 1.6, p = 0.046; SDQ Conduct 1.1 points higher, 95% CI = 0.45, 1.8; p = 0.007). Child ST was not significantly associated with emotional or behavioral health.

CONCLUSION

Future longitudinal research should examine the effects of changes in children's habitual PA on children's emotional and behavioral well-being.

IMPACT

To prevent declines in psychological and behavioral well-being among children who are currently regularly physically active, it is important to support their continued engagement in PA during periods when external barriers to PA are high. Increases in physical activity among children who are currently more sedentary may help limit the negative effects of stressors on children's emotional and behavioral well-being, but further research is needed.

The Performance of Ankle- and Waist-Based Accelerometry in Quantifying Physical Activity Intensity Among 6- to 24-Month-Year-Olds: A Semistructured Laboratory Study

OBJECTIVES

We aim to quantify the performance of accelerometry in objectively measuring physical activity (PA) intensity among infants and toddlers.

METHODS

Thirty-eight 6- to 24-month-olds participated in a 30-min, semistructured lab visit. Twenty-three (61%) children could walk independently. Children engaged in a variety of activities while wearing accelerometers on each ankle and at the waist. Visits were video recorded, and study team members independently coded the first three 5-s epochs of each minute for PA intensity using a 5-level scale ranging from 1 = completely sedentary to 5 = moderate-to-high intensity. Interrater agreement for PA classifications was excellent (median kappa per child = 0.85). A series of logistic regression models were fit to find the vector magnitude threshold per 5-s epoch that differentiated activity intensity above each PA level with ≥ 80% sensitivity.

RESULTS

Analyses included 3191 epochs; a median of 88 epochs per child. The classification performance applying all thresholds concurrently for the five PA intensity levels was poor for each wear location (agreement < 50%, kappa < 0.25). Classification improved when concatenating intensity levels, with the best performance comparing sedentary (levels 1-2) to nonsedentary (levels 3-5) and using data from the left ankle device: agreement ≥ 77.6%, kappa ≥ 0.44. Applying those novel thresholds to predict the total time spent in level 3-5 activities over all coded epochs using linear regression performed as well as using the sum of vector magnitude across epochs when using data from the left ankle device. Overall, the performance of the left ankle wear location was similar to the right ankle wear location and superior to the waist location.

CONCLUSIONS

Ankle-worn accelerometry had adequate validity to classify in-the-moment nonsedentary behaviours and total time spent nonsedentary over a time interval among this sample of infants and toddlers. While caution is warranted when generalizing these lab-based findings to naturalistic settings, findings provide insight into objective measures of PA for this age range.

Adherence to the 24-h Movement Behaviors Guidelines and Associations With Cognitive and Behavioral Self-Regulation Among Brazilian Preschoolers

BACKGROUND

Adherence to 24-h movement guidelines has been associated with early health benefits, including neurodevelopmental outcomes. However, the associations between these guidelines and Cognitive (CSR) and Behavioral (BSR) self-regulation in preschoolers are underexplored. This study investigated the associations between adherence to 24-h movement guidelines and CSR and BSR in Brazilian preschoolers.

METHODS

A total of 223 preschoolers (4.76 ± 0.32 years old; 50.67% boys) participated. Physical activity (PA) was assessed with Actigraph wGT3X. Parents reported children's sleep and screen time. CSR was evaluated through iPad games, and BSR was assessed using the Head, Toes, Knees, Shoulders test revised.

RESULTS

Boys showed higher adherence to the PA recommendation than girls (52.2% vs. 32.7%, χ2 = 0.003), whereas a higher percentage of girls did not adhere to any recommendations (23.6% vs. 12.4%, χ2 = 0.029). Positive association was found between adherence to combined PA and screen time with cognitive flexibility (β = 4.091 [95% CI: 0.699, 7.754]). Adherence to PA was associated with lower BSR scores (β = -7.104 [-13.52, -0.623]), as was adherence to combined PA and sleep duration (β = -8.813 [-15.794, -1.397]).

CONCLUSION

This study highlighted differences in adherence to movement behavior guidelines between boys and girls, as well as demonstrated that different combinations of these behaviors can affect preschoolers' cognitive and behavioral levels of self-regulation in distinct ways.

Optimal levels of sleep, sedentary behaviour, and physical activity needed to support cognitive function in children of the early years

BACKGROUND

Sleep, sedentary behaviour, physical activity, and the composition of these movement behaviours across the 24-h day are associated with cognitive function in early years children. This study used a Goldilocks day compositional data analysis approach to identify the optimal duration of sleep, sedentary behaviour, light physical activity, and moderate-to-vigorous physical activity associated with desired cognitive function outcomes in early years children.

METHODS

This cross-sectional study included 858 children aged 2.8-5.5 years from the Sleep and Activity Database for the Early Years. 24-h movement behaviours (sleep, sedentary behaviour, light physical activity, moderate-to-vigorous physical activity) were measured using ActiGraph accelerometers. Cognitive function was measured using three tasks from the Early Years Toolbox: visual-spatial working memory, response inhibition, and expressive vocabulary. A Goldilocks day compositional data analysis approach was used in R software to identify the optimal time-use compositions associated with the best 10% of the cognitive function scores.

RESULTS

The movement behaviour composition and the relative time spent in sleep and sedentary behaviour but not different intensities of physical activity were significantly associated with working memory (P ≤ 0.01). The movement behaviour composition and relative time spent in sleep, sedentary behaviour, and different intensities of physical activity were not significantly associated with response inhibition or expressive vocabulary (P > 0.2). Therefore, optimal time use was only determined for working memory. Optimal daily durations for working memory were observed with 11:00 (hr:min) of sleep, 5:42 of sedentary behaviour, 5:06 of light physical activity, and 2:12 of moderate-to-vigorous physical activity.

CONCLUSION

Working memory was the only cognitive function outcome related to the 24-h movement behaviour composition. Optimal sleep for working memory was consistent with current recommended durations, while optimal moderate-to-vigorous physical activity greatly exceeded minimal recommended levels. Optimal sedentary behaviour was longer and light physical activity was shorter than the sample average.

Evaluation of the ActiMotus Software to Accurately Classify Postures and Movements in Children Aged 3-14

BACKGROUND

ActiMotus, a thigh-accelerometer-based software used for the classification of postures and movements (PaMs), has shown high accuracy among adults and school-aged children; however, its accuracy among younger children and potential differences between sexes are unknown. This study aimed to evaluate the accuracy of ActiMotus to measure PaMs among children between 3 and 14 years and to assess if this was influenced by the sex or age of children.

METHOD

Forty-eight children attended a structured ~1-hour data collection session at a laboratory. Thigh acceleration was measured using a SENS accelerometer, which was classified into nine PaMs using the ActiMotus software. Human-coded video recordings of the session provided the ground truth.

RESULTS

Based on both F1 scores and balanced accuracy, the highest levels of accuracy were found for lying, sitting, and standing (63.2-88.2%). For walking and running, accuracy measures ranged from 48.0 to 85.8%. The lowest accuracy was observed for classifying stair climbing. We found a higher accuracy for stair climbing among girls compared to boys and for older compared to younger age groups for walking, running, and stair climbing.

CONCLUSIONS

ActiMotus could accurately detect lying, sitting, and standing among children. The software could be improved for classifying walking, running, and stair climbing, particularly among younger children.

A comparison of the physical activity levels of 3-to-6-year-old children with autism spectrum disorder and children with typical development

Background

Physical activity during early development is closely related to health. Differences in physical activity between young children with autism spectrum disorder and those with typical development are unclear. The purpose of this study was to compare the physical activity levels in children with autism spectrum disorder and typically developing children from the same area, including their sedentary physical activity, light physical activity, moderate-to-vigorous physical activity, and number of days in which the moderate-to-vigorous physical activity guideline recommendation of 60 min per day was met.

Methods

A total of 77 participants aged 3-6 years were included: 41 children with autism spectrum disorder (mean age = 61.41 ± 10.69 months) and 36 children with typical development (mean age = 60.36 ± 10.16 months). The physical activity of the children was measured using an ActiGraph GT3x accelerometer.

Results

There were no significant differences in daily sedentary physical activity (439.70 ± 54.98 vs. 450.42 ± 53.67) or moderate-to-vigorous physical activity (46.62 ± 18.93 vs. 47.47 ± 18.26) between the two groups. The average daily moderate-to-vigorous physical activity of the two groups did not reach 60 min, and they had similar proportions of participants who reached 60 min a given number of times (24.4% vs. 25%). Daily light physical activity was significantly higher in the autism spectrum disorder group (263.96 ± 43.17 vs. 242.32 ± 37.91, p < 0.05). The moderate-to-vigorous physical activity of both groups was similar and lower than the recommended minimum physical activity.

Conclusion

Targeted interventions should be considered in early intervention programs for children with autism spectrum disorder to increase their moderate-to-vigorous physical activity.

Feasibility and potential efficacy of a family-based intervention on promoting physical activity levels and fundamental movement skills in preschoolers: A cluster randomised controlled trial

Physical activity (PA) is crucial for preschool-aged children's health and development. However, limited evidence exists regarding the feasibility of implementing home-based interventions and how program components influence parent cognitions and practices and child PA. This study evaluated the feasibility and potential efficacy of a family-based PA intervention on objectively measured PA, fundamental movement skills (FMS), parental efficacy, support, goal setting and parent-child co-activity. Guided by social cognitive theory, an 8-week cluster randomised controlled trial was conducted in Hong Kong. The trial included parental workshops, FMS training, PA homework, social media activity sharing and exercise equipment provision. Data were collected at baseline (Time 1; April 2019) and at the end of the intervention period (Time 2; approximately 2 months later) from 108 parent-child pairs in five preschools. The intervention led to increased moderate-to-vigorous PA and FMS in children, along with improved parental self-efficacy, goal setting, supportiveness and co-participation. However, parental PA did not show significant changes. Parents expressed high satisfaction, supporting the need for tailoring interventions to address the unique needs and preferences of young children and their parents. Reinforcing the parental role and providing informative materials and training can promote healthy lifestyles in early childhood.

Long-form recording of infant body position in the home using wearable inertial sensors

Long-form audio recordings have had a transformational effect on the study of infant language acquisition by using mobile, unobtrusive devices to gather full-day, real-time data that can be automatically scored. How can we produce similar data in service of measuring infants' everyday motor behaviors, such as body position? The aim of the current study was to validate long-form recordings of infant position (supine, prone, sitting, upright, held by caregiver) based on machine learning classification of data from inertial sensors worn on infants' ankles and thighs. Using over 100 h of video recordings synchronized with inertial sensor data from infants in their homes, we demonstrate that body position classifications are sufficiently accurate to measure infant behavior. Moreover, classification remained accurate when predicting behavior later in the session when infants and caregivers were unsupervised and went about their normal activities, showing that the method can handle the challenge of measuring unconstrained, natural activity. Next, we show that the inertial sensing method has convergent validity by replicating age differences in body position found using other methods with full-day data captured from inertial sensors. We end the paper with a discussion of the novel opportunities that long-form motor recordings afford for understanding infant learning and development.

The sleep and activity database for the early years (SADEY) study: design and methods

BACKGROUND

Canada, Australia, the World Health Organization and other countries have released 24-hour movement guidelines for the early years which integrate physical activity, sedentary behaviour, and sleep, focusing on supporting children to achieve a healthy 24-hour day. The guideline evidence synthesis, however, highlighted the dearth of high-quality evidence, particularly from large-scale studies. The Sleep and Activity Database for the Early Years (SADEY) project aims to assemble a large, pooled database of 24-hour movement behaviours and health indicators in young children (birth to 5.99 years), to advance knowledge in these areas. This paper describes the SADEY design and methods.

METHODS

Data sets were identified with > 100 children and device-measured (hip-worn ActiGraph accelerometers) physical activity and sedentary behaviour, parent-reported or device-measured sleep, and at least one health outcome: physical (BMI, waist circumference, blood pressure), social-emotional (Strength and Difficulties Questionnaire), cognitive (Early Years Toolbox), or motor development (Test of Gross Motor Development 2). Led by the University of Wollongong co-ordinating centre, the SADEY project collates the datasets to create a pooled database.

FINDINGS

To date, 13 studies from 7 countries have been included in the database. Ethics clearance and data sharing agreements have been secured for all studies and the SADEY 1.0 database is being assembled including ~ 8,000 participants.

DISCUSSION

SADEY will be used to address questions of global importance to public health policy and practice, for example - Is the mix of movement behaviours across the 24-hour day associated with healthy development?, What is the optimal mix of these behaviours?, and; What factors can be targeted to support young children in achieving the optimal mix of 24-hour movement behaviours? Additionally, SADEY seeks to develop and disseminate protocols, develop capacity on the device-based measurement of movement behaviours, and seeks partnerships with stakeholders that promote knowledge translation on movement behaviours to support healthy development among young children.

Compliance with the 24-h movement behaviors guidelines among urban and rural Brazilian preschoolers

BACKGROUND

The importance of movement behaviors for health is well-known, although few studies have examined the compliance with movement guidelines in preschoolers from different living contexts. This study reported the compliance with the 24-h movement behaviors guidelines among low-income Brazilian preschoolers from rural and urban areas, according to age.

METHODS

A total of 453 preschoolers (n = 222 urban), aged between 3 and 5 years, provided physical activity (PA) data (Actigraph wGT3X). Sleep duration, and screen time were parent-reported. Preschoolers were classified as compliant/non- compliant with the 24-h movement guidelines, according to age. The association between prevalence of compliance with the recommendations and the children's living setting were estimated (SPSS; 27.0).

RESULTS

Preschoolers were active (mean = 299.19 ± 76.42; and 369.76 ± 95.56 min/day in urban and rural areas, respectively), though moderate-to-vigorous physical activity (MVPA) time was below the 60 daily minutes recommended in both urban and rural settings (mean = 38.39 ± 21.36; and 47.32 ± 24.28, respectively). None of the urban children complied with the three recommendations simultaneously, while in the rural area, only 2.6% were compliant. Single movement behaviors compliances in the urban setting were 6.8%, 28.8% and 5.4% for PA, sleep, and screen time, respectively; while for rural settings were 16.5%, 21.2%, and 7.4%. Living in the rural area was related to the compliance with PA recommendation for the 5-year-old preschoolers.

CONCLUSION

In both urban and rural Brazilian areas, very few preschoolers are compliant with the guidelines, and more than one third of the children do not comply with any of the recommendations. Strategies and programs to promote compliance with movement behaviors guidelines should consider children's living setting and their age groups.

Investigating young children's physical activity through time and place

BACKGROUND

Previous research indicates the start of primary school (4-5-year-old) as an essential period for the development of children's physical activity (PA) patterns, as from this point, the age-related decline of PA is most often observed. During this period, young children are exposed to a wider variety of environmental- and social contexts and therefore their PA is influenced by more diverse factors. However, in order to understand children's daily PA patterns and identify relevant opportunities for PA promotion, it is important to further unravel in which (social) contexts throughout the day, PA of young children takes place.

METHODS

We included a cross-national sample of 21 primary schools from the Startvaardig study. In total, 248 children provided valid accelerometer and global positioning (GPS) data. Geospatial analyses were conducted to quantify PA in (social) environments based on their school and home. Transport-related PA was evaluated using GPS speed-algorithms. PA was analysed at different environments, time-periods and for week- and weekend days separately.

RESULTS

Children accumulated an average of 60 min of moderate-to-vigorous PA (MVPA), both during week- and weekend days. Schools contributed to approximately half of daily MVPA during weekdays. During weekends, environments within 100 m from home were important, as well as locations outside the home-school neighbourhood. Pedestrian trips contributed to almost half of the daily MVPA.

CONCLUSIONS

We identified several social contexts relevant for children's daily MVPA. Schools have the potential to significantly contribute to young children's PA patterns and are therefore encouraged to systematically evaluate and implement parts of the school-system that stimulate PA and potentially also learning processes. Pedestrian trips also have substantial contribution to daily MVPA of young children, which highlights the importance of daily active transport in school- and parental routines.

Pre-school-based behaviour change intervention to increase physical activity levels amongst young children: a feasibility cluster randomised controlled trial

Background

A significant rise in childhood obesity worldwide over the past three decades highlights the urgent need for early interventions, especially in preschools as key settings for child development. This study aimed to assess the feasibility and fidelity of a randomised controlled trial of "I'm an Active Hero" (IAAH), a theory- and evidence-based multi-component behaviour change intervention targeting physical activity and sedentary behaviour amongst preschool-aged children.

Methods

Two preschools in Taif city, Saudi Arabia were randomly assigned to either the intervention (n = 3 classrooms) or the usual curriculum control group (n = 3 classrooms). The intervention ran for 10 weeks from February to April 2023 and consisted of teacher-led physical activity and sedentary behaviour sessions in preschools, with an additional interactive home component. Primary outcome measures included intervention fidelity, recruitment rates, attrition rates, and compliance with trial procedures. Secondary outcomes included body mass index (BMI), objectively measured physical activity, and sedentary time via the ActiGraph GT3X accelerometer. Outcomes were measured at baseline and at 10 weeks in both study arms.

Results

The preschool intervention component had high fidelity (93.3%), but the home component fidelity was lower (74%). A cluster-level recruitment rate of 12% (13/112 centres) was attained, whilst the individual-level recruitment rate stood at 36% (52/143 children, mean age of 4.16 years; 23 girls). Attrition was 10%. Compliance varied with 90% for BMI, 71% for accelerometery, and 45% for questionnaires. The intervention group showed small decreases in BMI, slight increases in physical activity, and decreases in sedentary time at follow-up compared to the control group. Parents, facilitators, and assistant teachers considered the intervention to be feasible and beneficial.

Conclusion

The IAAH intervention was feasible to implement in Saudi Arabian preschools. Facilitators showed high fidelity in delivering it. However, preliminary data did not demonstrate effectiveness. A more comprehensive evaluation across a broader population is warranted. The intervention could be revised to optimise recruitment, compliance, and fidelity of the home-based component. Successful elements from this pilot should be retained whilst adaptations to implementation are made to strengthen key areas.Clinical trial registration: ClinicalTrials.gov, NCT05754359.

Exploring Factors Associated With Accelerometer Validity Among Ethnically Diverse Toddlers

PURPOSE

Studying physical activity in toddlers using accelerometers is challenging due to noncompliance with wear time (WT) and activity log (AL) instructions. The aims of this study are to examine relationships between WT and AL completion and (1) demographic and socioeconomic variables, (2) parenting style, and (3) whether sedentary time differs by AL completion.

METHODS

Secondary analysis was performed using baseline data from a community wellness program randomized controlled trial for parents with toddlers (12-35 mo). Parents had toddlers wear ActiGraph wGT3x accelerometers and completed ALs. Valid days included ≥600-minute WT. Analysis of variance and chi-square analyses were used.

RESULTS

The sample (n = 50) comprised racial and ethnically diverse toddlers (mean age = 27 mo, 58% male) and parents (mean age = 31.7 y, 84% female). Twenty-eight families (56%) returned valid accelerometer data with ALs. Participants in relationships were more likely to complete ALs (P < .05). Toddler sedentary time did not differ between those with ALs and those without.

CONCLUSIONS

We found varied compliance with WT instructions and AL completion. Returned AL quality was poor, presenting challenges in correctly characterizing low-activity counts to improve internal validity of WT and physical activity measures. Support from marital partners may be important for adherence to study protocols.

How energy balance-related behaviours, temperament, stress and overweight associate: a cross-sectional study of Finnish preschoolers

OBJECTIVE

This study aimed to (1) examine the clustering of energy balance-related behaviours (EBRB) and (2) investigate whether EBRB clusters, temperament and hair cortisol concentration (HCC) associate with overweight.

DESIGN

We assessed food consumption using food records, screen time (ST) using sedentary behaviour diaries, sleep consistency and temperament (negative affectivity, surgency, effortful control) using questionnaires and HCC using hair samples. Accelerometers were used to assess physical activity (PA) intensities, sleep duration and sleep efficiency. Researchers measured each child's weight and height. We used finite mixture models to identify EBRB clusters and multilevel logistic regression models to examine the associations between EBRB clusters, temperament, HCC and overweight.

SETTING

The cross-sectional DAGIS survey, data collected in 2015-2016.

PARTICIPANTS

Finnish 3-6-year-olds (n 864) recruited through preschools.

RESULTS

One-third of the participants were categorised into the cluster labelled 'Unhealthy diet, excessive screen time', characterised by unhealthy dietary choices (e.g. greater consumption of high-fat, high-sugar dairy products) and longer ST. Two-thirds were categorised into the second cluster, labelled 'Healthy diet, moderate screen time'. PA and sleep were irrelevant for clustering. Higher negative affectivity and lower effortful control associated with the 'Unhealthy diet, excessive screen time' cluster. EBRB clusters and HCC did not associate with overweight, but surgency was positively associated with overweight (OR = 1·63, 95 % CI 1·17, 2·25).

CONCLUSIONS

Of the EBRB, food consumption and ST seem to associate. As temperament associates with EBRB clusters and overweight, tailored support acknowledging the child's temperament could be profitable in maintaining a healthy weight.

Prevalence and Health Associations of Meeting the World Health Organization Guidelines for Physical Activity, Sedentary Behavior, and Sleep in Preschool-Aged Children: The SUNRISE Mongolia Pilot and Feasibility Study

BACKGROUND

There is a lack of evidence regarding 24-hour movement behaviors of young children from low- and middle-income countries. This study examined Mongolian preschoolers' adherence to the World Health Organization's guidelines for physical activity, sedentary behavior, and sleep; their associations with health indicators, and the feasibility of the SUNRISE International study in Mongolia.

METHODS

Preschool-aged children were recruited from 5 kindergartens in urban and rural areas of Ulaanbaatar city and Tuv province in Mongolia. Physical activity and sedentary behavior were measured by an ActiGraph accelerometer worn for 5 consecutive days. Screen time and sleep were reported by parents. The National Institute of Health and Early Years Toolboxes were used to assess motor skills and executive function, respectively.

RESULTS

One hundred and one children participated in the study (mean age = 4.82 y, boys = 58), with 88% (n = 89) having complete data for analysis. The proportion of children who met the recommendations for physical activity, sedentary screen time, and sleep was 61%, 23%, and 82%, respectively. Only 7% met all recommendations. Meeting the sleep recommendation individually (P = .032) and in combination with the physical activity recommendation was associated with better gross (P = .019) and fine (P = .042) motor skills. Spending more time in physical activity was positively correlated with motor development. Results confirmed that the SUNRISE study protocol was feasible, age-appropriate, and enjoyable for children.

CONCLUSIONS

The results of the SUNRISE pilot study will help inform the SUNRISE Mongolia main study and lay the groundwork for future research into children's 24-hour movement behaviors in Mongolia.

Educator-Perceived Barriers and Facilitators to Structured-Physical Activity in Early Childhood Centres: A Systematic Review

Purpose: Physical activity (PA) and motor competence development are vital for young children, yet many early childhood education and care (ECEC) centers struggle to successfully implement PA programs, particularly those organized and led by educators. This review aimed to synthesize qualitative literature to (1) identify educator-perceived barriers and facilitators to structured-PA in ECEC centers, and (2) map these to the COM-B model and Theoretical Domains Framework (TDF). Methods: Following PRISMA guidelines, a systematic search of five databases was conducted in April 2021 and updated in August 2022. Records were screened in Covidence software using predefined eligibility criteria. Using the framework synthesis method, data extraction and synthesis were conducted in coding forms in Excel and NVivo. Results: Of 2382 records identified, 35 studies were included, representing 2,365 educators across 268 ECEC centers in 10 countries. Using the COM-B model and TDF, an evidence-informed framework was developed. Findings revealed the greatest barriers concerned educator "opportunity" (e.g. competing time and priorities, policy tensions, indoor/outdoor space constraints) and "capability" (e.g. lack of PA knowledge and practical, hands-on skills) to implement structured-PA. Although fewer studies reported factors that influenced educator "motivation", several themes intersected across the three COM-B components illustrating the complexity of behavioral determinants in this setting. Conclusions: Interventions grounded in theory that utilize a systems approach to target multiple levels of influence on educator behavior, and are flexible and adaptable locally, are recommended. Future work should seek to address societal barriers, structural challenges in the sector, and the PA educational needs of educators. PROSPERO Registration: CRD42021247977.

Development and content validity of an application to assess 24-hour movement behaviors in 0-4-year-old children involving end-users and key stakeholders: the My Little Moves app

BACKGROUND

Recently, research focus has shifted to the combination of all 24-h movement behaviors (physical activity, sedentary behavior and sleep) instead of each behavior separately. Yet, no reliable and valid proxy-report tools exist to assess all these behaviors in 0-4-year-old children. By involving end-users (parents) and key stakeholders (researchers, professionals working with young children), this mixed-methods study aimed to 1) develop a mobile application (app)-based proxy-report tool to assess 24-h movement behaviors in 0-4-year-olds, and 2) examine its content validity.

METHODS

First, we used concept mapping to identify activities 0-4-year-olds engage in. Parents (n = 58) and professionals working with young children (n = 21) generated a list of activities, sorted related activities, and rated the frequency children perform these activities. Second, using multidimensional scaling and cluster analysis, we created activity categories based on the sorted activities of the participants. Third, we developed the My Little Moves app in collaboration with a software developer. Finally, we examined the content validity of the app with parents (n = 14) and researchers (n = 6) using focus groups and individual interviews.

RESULTS

The app has a time-use format in which parents proxy-report the activities of their child, using eight activity categories: personal care, eating/drinking, active transport, passive transport, playing, screen use, sitting/lying calmly, and sleeping. Categories are clarified by providing examples of children's activities. Additionally, 1-4 follow-up questions collect information on intensity (e.g., active or calm), posture, and/or context (e.g., location) of the activity. Parents and researchers considered filling in the app as feasible, taking 10-30 min per day. The activity categories were considered comprehensive, but alternative examples for several activity categories were suggested to increase the comprehensibility and relevance. Some follow-up questions were considered less relevant. These suggestions were adopted in the second version of the My Little Moves app.

CONCLUSIONS

Involving end-users and key stakeholders in the development of the My Little Moves app resulted in a tailored tool to assess 24-h movement behaviors in 0-4-year-olds with adequate content validity. Future studies are needed to evaluate other measurement properties of the app.

Continuous-time modeling of the multivariate relationships between physical activity levels and stationary time in preschool-aged children: an investigation of the ActivityStat hypothesis

BACKGROUND

The ActivityStat hypothesis proposes that an increase or decrease in physical activity (PA) greater than a certain set point activates behavioural and/or energy compensatory responses to maintain a stable level of total energy expenditure. Few studies have tested this hypothesis in children and even fewer have focused on young children. Therefore, the purpose of this study was to investigate the ActivityStat hypothesis by examining the presence and timeframe of the relationships among PA levels and stationary time (ST) in preschool-aged children.

METHODS

A secondary analysis was performed on repeated measurement data (i.e., day-to-day activity) involving 98 preschool-aged children (age: 4.5 ± 0.7 years) in Edmonton, Canada. Participants were asked to wear an ActiGraph wGT3X-BT on the waist for 7 consecutive days to assess PA levels (i.e., light PA [LPA], and moderate-to-vigorous PA[MVPA]) and ST. Bayesian continuous-time structural equation modeling (CT-SEM) was used to examine the relationship between behaviours over time and the timeframe during which these relationships occur.

RESULTS

Each behaviour (i.e., LPA, MVPA, and ST) positively and meaningfully predicted itself at a later time. These relationships persisted up to 0.5 days later, at which point past behaviour no longer meaningfully predicted future behaviour. In contrast, no relationships were observed between the three behaviours.

CONCLUSIONS

This is the first study to investigate the ActivityStat hypothesis using Bayesian CT-SEM in preschool-aged children. When simultaneously taking into account all dynamic relationships suggested by the ActivityStat, the findings fail to support the hypothesis.

Association between biomarkers of redox status and cytokines with different patterns of habitual physical activity in eutrophic and overweight/obese preschoolers: multivariate analysis of a cross-sectional study

BACKGROUND

Although it is well known that obesity is frequently associated with reduced levels of habitual physical activity (HPA), which contributes to determining severe oxidative stress and inflammatory state, this association is however unknown in preschoolers so far. This study aimed to investigate the association between biomarkers of redox status and cytokines with different patterns of HPA according to the adiposity of preschoolers.

METHODS

A cross-sectional study was conducted in 50 preschoolers (25 overweight/obese, OW/OB and 25 eutrophic, EU), matched for age, sex, economic level, and maternal education. Total antioxidant capacity (TAC), superoxide dismutase (SOD) and catalase (CAT) activities, substances reactive to thiobarbituric acid (TBARS), soluble tumor necrosis factor receptors (sTNFRs), and leptin levels were evaluated. HPA levels were evaluated by accelerometry (ActiGraph GT9X accelerometer). Correlation, multiple linear regression, and partial least squares regression analysis were used to determine the association between redox status biomarkers and cytokines with different patterns of HPA (HPA level, bouts of moderate to vigorous physical activity [MVPA], and multivariate pattern of HPA) in EU and OW/OB preschoolers.

RESULTS

OW/OB preschoolers had lower CAT activity, higher levels of TAC, TBARS, and cytokines, and similar levels of HPA to EU preschoolers. In EU preschoolers, SOD activity exhibited a stronger negative association with moderate intensity ranges of HPA (R2 = 0.18), and negative correlation with sTNFRs (r = -0.40 to -0.46). TBARS had a stronger positive association with ranges of light intensity in the multivariate pattern of HPA (R2 = 0.10). In OW/OB preschoolers, the HPA multivariate associative pattern was predominantly from vigorous intensity ranges. Thus, SOD activity had a positive association with the multivariate pattern of HPA (R2 = 0.38) and MVPA bouts (β [95% CI] = 0.457 [0.0026. 0.0576]). TAC had a negative association with the multivariate pattern of HPA (R2 = 0.38) and MVPA bouts (β [95% CI] = -0.718 [-0.0025. -0.0003]). Additionally, leptin levels were lower in OW/OB preschoolers engaged in vigorous physical activity (VPA) (8000-9999 counts/min) for longer periods of time.

CONCLUSION

The results of this study indicate that OW/OB preschoolers have higher levels of oxidative stress biomarkers and pro-inflammatory cytokines compared to EU preschoolers. Moreover, VPA may exert antioxidative and anti-inflammatory effects in OW/OB preschoolers.

Effects of Cognitively Engaging Physical Activity on Preschool Children's Cognitive Outcomes

Research combining physical activity with the training of cognitive skills such as executive functions is emerging as a novel and fruitful intervention approach for children. Purpose: This study aimed to examine the impact of an intervention program including cognitively engaging physical activity on preschool children's cognitive outcomes and physical activity. Methods: Children (N = 144, 65 female; Mage = 4.41 years, SD = 0.61), randomly assigned to one of three groups: cognitively engaging physical activity (CPA; i.e., storytelling, cognitive activities, and motor tasks, n = 55), cognition (i.e., storytelling and cognitive activities without motor tasks, n = 48), or control (i.e., traditional storytelling, n = 41). Sessions lasted approximately 17 minutes, conducted twice a week, for 6 weeks. Children's executive function, self-regulation, and related outcomes (i.e., numeracy) were assessed at baseline and again-along with perceived enjoyment-at the end of the program. Accelerometers measured children's physical activity during each session. Teachers completed a logbook for each session, and two fidelity checks per preschool took place by the researcher. Main analyses used linear mixed models adjusted for covariates (age, sex) and clustering at the preschool level. Results: Results showed no significant group by time interaction for executive function, self-regulation, numeracy, enjoyment. During the sessions, children in the CPA group were more physically active than children in the cognition and control groups. Conclusion: While we did not find the expected amplified cognitive benefits, making storytelling more active has the potential to meet two needs (increase cognitive stimulation and physical activity levels) in one deed.

Paths towards a healthier BMI among short and adequate sleepers: A pathway network analysis considering movement behaviors in low-income preschoolers

INTRODUCTION

Short sleep duration has been seen as a predictor of higher body mass index (BMI) in youth. Sleep duration varies substantially along early childhood, and the paths towards a healthier BMI, considering the other movement behaviors (physical activity-PA and screen time) are unexplored in preschoolers.

AIM

To construct a sleep-BMI model to capture the direct and indirect paths to intervening towards a healthier BMI, according to low-income preschoolers' compliance with the other movement behaviors.

METHODS

Two hundred and seventy two preschoolers (4.5 ± 0.0; 138 boys) participated in the study. Sleep and screen time (ST) were assessed in a face-to-face interview with primary caregivers. PA was assessed using accelerometer (wGT3X-BT). Preschoolers were categorized as compliant or not with sleep, screen time, total and moderate to vigorous PA recommendations. BMIz-score was calculated according to preschoolers' sex and age. All the assessed variables, besides sex and age were included in a Network Pathway Analysis (NPA) according to age as nodes.

RESULTS

At 3 years old, a direct and negative path between sleep-BMIz score was observed. At four and 5 years old, this relationship became positive. Further, girls were more compliant with sleep, ST and total PA recommendations. Total PA (TPA) showed the highest expected influence value in the general, 3 and 4 years old NPA.

CONCLUSION

The NPA analysis showed different directions for the relationship between sleep and BMIz score, according to age. Intervention strategies to a healthier BMI among preschoolers compliant or not with sleep recommendations should focus in increasing TPA.

Longitudinal associations between sleep and weight status in infants and toddlers

BACKGROUND

The limited research assessing relationships between sleep duration and weight status in infants and toddlers relies primarily on parent-reported sleep and cross-sectional studies.

OBJECTIVES

Examine whether average sleep duration and changes in sleep duration among 6-24-month-old children were associated with weight-for-length z-scores, and whether these associations varied by race/ethnicity, socioeconomic status and sex.

METHODS

Data were collected when children were approximately 6, 12, 18 and 24 months old (N = 116). Sleep duration was measured using actigraphy. Weight-for-length z-scores were calculated using children's height and weight. Physical activity was assessed using accelerometry. Diet was assessed using a feeding frequency questionnaire. Demographic characteristics included sex, race/ethnicity and socioeconomic status. Separate associations of between- and within-person changes in sleep duration were estimated with weight-for-length z-score treated as the outcome variable in linear mixed model analyses. Additional models were assessed that included interactions between sleep and demographic characteristics.

RESULTS

At time points where children slept longer at night compared to their own average, their weight-for-length z-score was lower. This relationship was attenuated by physical activity levels.

CONCLUSIONS

Increasing sleep duration can improve weight status outcomes in very young children who have low physical activity levels.

Physical activity in infancy and early childhood: a narrative review of interventions for prevention of obesity and associated health outcomes

In the context of the childhood obesity epidemic, this narrative review aims to explore opportunities to promote physical activity (PA) between birth and age 5 years as well as the health outcomes associated with PA in early childhood. Although early childhood is an ideal time to promote healthy habits, guidelines for PA have often ignored early childhood given the limited evidence for children <5 years old. Herein we discuss and highlight infant, toddler and preschool age interventions to promote PA and prevent obesity both in the short and long-term. We describe novel and modified interventions to promote improved early childhood health outcomes, encompassing cardiorespiratory, muscle, and bone strengthening components necessary for short-term motor development and long-term health. We call for new research aimed at developing and testing innovative early childhood interventions that may be performed in home or childcare settings, monitored by parents or caregivers.

Impact of an Interdisciplinary Educational Programme on Students' Physical Activity and Fitness

Educational initiatives and actions are needed to provide students with skills to create active habits and lifestyles in order to increase the physical activity and fitness levels of young people. The main objective of this study was to analyse the effects of a classroom-based physical activity and life skills programme on students' physical activity and fitness levels. The sample consisted of 65 students in the 6th grade of Primary Education, aged between 11 and 13 years (11.86 ± 0.53), divided into a control group (CG) and an experimental group (EG) for convenience and accessibility. This was a quasi-experimental, repeated measures, longitudinal cut-off research design. For 16 weeks, an interdisciplinary educational programme based on a combination of classroom-based physical activity and life skills was implemented. The results showed that the educational programme had a positive effect on students' physical activity levels during school hours, specifically on reducing sedentary time (p < 0.001) and increasing light (p < 0.001) and moderate-to-vigorous (p < 0.001) physical activity. Positive effects were also found on the variables of explosive strength (p < 0.05) and aerobic capacity (p < 0.05) related to physical fitness. In conclusion, interdisciplinary educational programmes based on the promotion of physical activity and life skills could contribute to the development of responsible daily physical activity habits in students to facilitate their transfer to other environments (social and family) outside school.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Associations of activity, sedentary, and sleep behaviors with cognitive and social-emotional health in early childhood

Background

Early childhood is important for cognitive and social-emotional development, and a time in which to promote healthy movement behaviors (sedentary behavior, physical activity, and sleep). Movement behaviors may have interactive influences on cognition and social-emotional factors in young children, but most previous research has explored them independently. The purpose of this study was to determine if movement behaviors are associated with measures of cognitive and social-emotional health in young children and if so, to describe optimal compositions of movement behaviors of a daily cycle for such outcomes.

Methods

Children (n = 388, 33 to 70 months, 44.6% female) from a clinical trial (ClinicalTrials.gov ID: NCT03285880, first posted September 18, 2017) wore accelerometers on their wrists for 24-h for 9.56 ± 3.3 days. Movement behavior compositions consisted of time spent in sedentary behaviors, light intensity physical activity, moderate to vigorous intensity physical activity (MVPA), and sleep. Outcomes were cognitive (receptive vocabulary, declarative and procedural memory, and executive attention) and social-emotional measures (temperament and behavioral problems). Compositional linear regression models with isometric log ratios were used to investigate the relations between the movement behavior composition and the cognitive and social-emotional health measures. If a significant association was found between the composition and an outcome, we further explored the "optimal" 24-h time-use for said outcome.

Results

Movement behavior compositions were associated with receptive vocabulary. The composition associated with the predicted top five percent of vocabulary scores consisted of 12.1 h of sleep, 4.7 h of sedentary time, 5.6 h of light physical activity, and 1.7 h of MVPA.

Conclusions

While behavior compositions are related to vocabulary ability in early childhood, our findings align with the inconclusiveness of the current evidence regarding other developmental outcomes. Future research exploring activities within these four movement behaviors, that are meaningful to cognitive and social-emotional development, may be warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s44167-023-00016-6.

Accelerometer-Measured Physical Activity and Sedentary Time among Children in Japan before and during COVID-19: A Cross-Sectional and Longitudinal Analysis

This study examined changes in physical activity (PA), sedentary behavior (SB), screen time, sleep, and executive function among Japanese preschoolers between COVID-19 pre-pandemic and pandemic periods, using cross-sectional and longitudinal data. Accelerometer data from 63 children aged 5-6 years were collected from three kindergartens in Tokyo, Japan, in late 2019 (pre-COVID-19). This was compared to the data of 49 children aged 5-6 years from the same kindergartens, collected in late 2020 (during COVID-19). Sixteen children in the pre-COVID-19 cohort also participated in the 2020 survey and provided data for the longitudinal analysis. The mean minutes of PA, SB, screen time, and sleep duration, as well as executive function, were compared between the pre- and during COVID-19 cohorts. After adjusting for school, sex, and accelerometer wear time, there were no significant differences in any of the measured outcomes between the two cohorts. However, the analysis of longitudinal data revealed significant increases in time spent in SB and on screens, and a decrease in light-intensity PA and sleep duration during the pandemic compared to the pre-pandemic period. Results suggest that, despite the COVID-19 pandemic, young children's activity levels and SB did not significantly differ from pre-pandemic levels. However, school-aged children's SB, light PA, and sleep time were affected, although this cannot be disentangled from the effects of the transition to school.

Relationships between physical activity, fundamental motor skills, and body mass index in preschool children

Purpose

To investigate whether there is a potential relationship between physical activity (PA), fundamental motor skills (FMS), and Body Mass Index (BMI) in preschool children and to further explore the differences in PA and FMS between normal-weight and overweight/obese preschool children.

Method

Participants were 366 preschool children aged 3 to 6 years; 358 completed all tests (194 boys and 164 girls). PA, FMS, body weight, and height were measured by triaxial accelerometer, the Test of Gross Motor Development, Second Edition (TGMD-2), and anthropometry measurement, respectively.

Result

The overall rate of overweight/obesity was 17.0%, with no significant gender difference (χ ² = 0.628, p = 0.428). Older children perform significantly better in both object control skills and locomotor skills. Independent samples t-tests were used to examine the difference between genders on FMS and PA: girls in the 5-year-old group display better locomotor skills (p = 0.012) than boys. Boys spent more time on moderate-to-vigorous physical activity (MVPA) and less time on sedentary activity when compared to girls. Results of partial correlation analysis showed that PA was significantly and positively correlated with both locomotor skills and object control skills in preschool children (p < 0.01), while there was no correlation between FMS, PA level, and BMI. Results of ANCOVA revealed no significant difference in FMS between normal-weight and overweight or obese preschool children; normal-weight girls had significantly longer MPA and MVPA duration and significantly shorter sedentary periods than overweight or obese girls (p < 0.05).

Conclusion

Overweight/obesity in preschool children requires effective measures. PA is positively associated with FMS, while BMI is not potentially related to FMS or PA in preschool years. Overweight or obese girls should develop healthier weight status by increasing MVPA hours and reducing sedentary time.

Validity and Reliability of Questionnaires That Assess Barriers and Facilitators of Sedentary Behavior in the Pediatric Population: A Systematic Review

We systematically reviewed the literature about the validity and reliability of barriers and facilitators of sedentary behavior questionnaires for children and adolescents, considering accelerometers as the reference method. We included studies that assessed the agreement between the barriers and facilitators of sedentary behavior through a questionnaire and an objective measure (e.g., accelerometry). We searched four electronic databases (MEDLINE/PubMed, CINAHL, Web of Science, and SCOPUS): these databases were searched for records from inception to 5 March 2021, and updated to November 2022. The search strategy used the following descriptors: children and adolescents; barriers or facilitators; questionnaires; accelerometers; and validation or reliability coefficient. Studies identified in the search were selected independently by two reviewers. The inclusion criteria were: (i) population of children and adolescents, (ii) original studies, (iii) subjective and objective measurement methods, (iv) studies that report validity or reliability, and (v) population without specific diseases. Seven studies were eligible for our review. The main exclusion reasons were studies that did not report validity or reliability coefficients (56.6%) and non-original studies (14.5%). The participants' ages in the primary studies ranged from 2 to 18 years. Cronbach's alpha coefficient was the most reported reliability assessment among the eligible articles, while Pearson and Spearman's coefficients were prevalent for validity. The reliability of self-report questionnaires for assessing sedentary behavior ranged from r = 0.3 to 1.0. The validity of the accelerometers ranged from r = -0.1 to 0.9. Family environment was the main factor associated with sedentary behavior. Our findings suggest that questionnaires assessing the barriers and facilitators of sedentary behavior are weak to moderate. PROSPERO Registration (CRD42021233945).

Systematic review of accelerometer-based methods for 24-h physical behavior assessment in young children (0-5 years old)

BACKGROUND

Accurate accelerometer-based methods are required for assessment of 24-h physical behavior in young children. We aimed to summarize evidence on measurement properties of accelerometer-based methods for assessing 24-h physical behavior in young children.

METHODS

We searched PubMed (MEDLINE) up to June 2021 for studies evaluating reliability or validity of accelerometer-based methods for assessing physical activity (PA), sedentary behavior (SB), or sleep in 0-5-year-olds. Studies using a subjective comparison measure or an accelerometer-based device that did not directly output time series data were excluded. We developed a Checklist for Assessing the Methodological Quality of studies using Accelerometer-based Methods (CAMQAM) inspired by COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN).

RESULTS

Sixty-two studies were included, examining conventional cut-point-based methods or multi-parameter methods. For infants (0-12 months), several multi-parameter methods proved valid for classifying SB and PA. From three months of age, methods were valid for identifying sleep. In toddlers (1-3 years), cut-points appeared valid for distinguishing SB and light PA (LPA) from moderate-to-vigorous PA (MVPA). One multi-parameter method distinguished toddler specific SB. For sleep, no studies were found in toddlers. In preschoolers (3-5 years), valid hip and wrist cut-points for assessing SB, LPA, MVPA, and wrist cut-points for sleep were identified. Several multi-parameter methods proved valid for identifying SB, LPA, and MVPA, and sleep. Despite promising results of multi-parameter methods, few models were open-source. While most studies used a single device or axis to measure physical behavior, more promising results were found when combining data derived from different sensor placements or multiple axes.

CONCLUSIONS

Up to age three, valid cut-points to assess 24-h physical behavior were lacking, while multi-parameter methods proved valid for distinguishing some waking behaviors. For preschoolers, valid cut-points and algorithms were identified for all physical behaviors. Overall, we recommend more high-quality studies evaluating 24-h accelerometer data from multiple sensor placements and axes for physical behavior assessment. Standardized protocols focusing on including well-defined physical behaviors in different settings representative for children's developmental stage are required. Using our CAMQAM checklist may further improve methodological study quality.

PROSPERO REGISTRATION NUMBER

CRD42020184751.

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.

Associations between meeting the Canadian 24-hour movement guidelines and physical, cognitive, social-emotional, and overall development in early childhood

BACKGROUND

The importance of all movement behaviours (i.e., sleep, sedentary behaviour, and physical activity) for children's health has led to the creation of national and international 24-h movement behaviour guidelines for children. Few studies have examined the associations between guideline adherence and a broad array of health indicators in early childhood, and no study has done so with composite development scores for overall development. The objective of the present study was to examine associations for 24-h movement guideline adherence with physical, cognitive, social-emotional, and overall development indicators in a sample of 3-5-year-olds.

METHODS

Children (n = 95) were recruited for this cross-sectional study in Edmonton, Canada. Sleep, light-intensity physical activity, and moderate- to vigorous-intensity physical activity were measured with ActiGraph wGT3X-BT accelerometers. Screen time was measured via parental-report. Guideline recommendation adherence was categorized using the Canadian 24-h Movement Guidelines. Composite z-scores were created for physical (i.e., adiposity, growth, motor skills), cognitive (i.e., vocabulary, executive functions), social-emotional (i.e., self-regulation, social-emotional behaviours), and overall development. Linear regression models were conducted to examine associations between meeting different recommendation combinations (e.g., physical activity alone, combination of physical activity and sleep), and number of recommendations met (e.g., meeting only one of any of the recommendations) with each composite development outcome variable adjusted for relevant covariates.

RESULTS

Most children were 3-4 years old (77%) and males (69%). The physical activity guideline recommendation was the most frequently met single recommendation (94%), while the physical activity and sleep recommendations (80%) were the most frequently met combination of two recommendations. Further, 43% of children met all three recommendations. Meeting the sleep recommendation was positively associated with overall development (B: 0.29; 95% CI: 0.08-0.50), while meeting both the sleep and physical activity recommendations was positively associated with overall (B: 0.28; 95% CI: 0.10-0.46) and physical (B: 0.27; 95% CI: 0.03-0.51) development.

CONCLUSIONS

Meeting sleep recommendations alone, as well as the combination of sleep and physical activity recommendations were associated with better physical and overall development in this sample. Future research should continue to examine a broad array of development outcomes using longitudinal study designs across early childhood.

A blended professional learning intervention for early childhood educators to target the promotion of physical activity and healthy eating: the HOPPEL cluster randomized stepped-wedge trial

BACKGROUND

Childcare centres are important environments for promoting physical activity and healthy eating. Blended approaches to professional learning may help overcome existing challenges for educators in promoting these behaviours. This study aimed to test the effect of a blended professional learning program on healthy eating and physical activity in childcare.

METHODS

Cluster randomized stepped-wedge trial in 15 childcare centres in Tasmania, Australia. Children aged 2-5y who attended at least two days per week were eligible to participate. Random assignment occurred at the centre level. Centre names were drawn out of a hat and then subsequently allocated to one of the three steps. The intervention comprised a 12-week blended professional learning program for educators. The main outcome was centre-level physical activity and healthy eating, assessed using the Environment and Policy Assessment Observation System (EPAO). All data collectors were blinded to step allocation. Analyses were according to intention to treat. The trial was registered with the Australian New Zealand Clinical Trial Registry (ACTRN12618000346279, date registered: 07/03/2018).

RESULTS

Centres were recruited between January 2016 and February 2016. All centres were retained for the duration of the study. A total of 313 children were recruited with 291 analysed at the completion of the study (93%). The difference between groups for the EPAO total score was significant at the end of the maintenance period (adjusted difference = 14.63, 95% CI [1.33, 27.92], p = 0.03). Significant differences were found for the percentage of time children spent in light-intensity physical activity at the end of the intervention (adjusted difference = 0.01, 95% CI [0.00,0.01], p = 0.02) and maintenance periods (adjusted difference = 0.01, 95% CI [0.00,0.02], p = 0.04). To the best of the authors knowledge, there were no adverse events.

CONCLUSION

This intervention achieved a sustained improvement in physical activity and healthy eating in childcare centres. Further, it can be easily integrated into existing service provision, especially among centres with limited access to professional learning.

TRIAL REGISTRATION

The study was registered with the Australian and New Zealand Clinical Trials Registry ( ACTRN12618000346279 , date registered: 07/03/2018).

Measuring change in adolescent physical activity: Responsiveness of a single item

Self-report measures are frequently used to assess change in physical activity (PA) levels. Given the limited data from adolescent populations, the primary objective of this study was to examine the responsiveness of a single item measure (SIM) of PA for adolescents to detect change in moderate-to-vigorous physical activity (MVPA) using accelerometer data as the reference measure. A secondary objective was to provide further data on the validity of the measure at one point in time. The validity of the SIM to determine the number of days ≥60 minutes of MVPA was based on data from 200 participants (62% female; age: 14.0 ± 1.6 years) and analysis of change was based on data from 177 participants (65% female; age: 14.0 ± 1.6 years). Validity of change in days ≥60 minutes of MVPA was examined through agreement in classification of change between the SIM and accelerometry as the reference measurement and Spearman’s correlation. Cohen’s d and standardised response means were used to assess the responsiveness to change of the measure. The responsiveness of the SIM and accelerometer data were comparable and modest (0.27–0.38). The correlation for change in number of days ≥60 minutes MVPA between the SIM and accelerometery was low (r = 0.11) and the accuracy of the SIM for detecting change, using accelerometry as the reference, was only marginally above chance (53%). Therefore, the adolescent version of the SIM is adequate for assessing PA at a single time point but not recommended for assessing change.

Patterns of objectively measured motor activity among infants developing ASD and concerns for ADHD

BACKGROUND

Heightened motor activity is a hallmark of attention-deficit/hyperactivity disorder (ADHD), yet high activity levels are also often reported in young children with autism spectrum disorder (ASD). It is currently unclear whether increased motor activity represents a distinct versus shared early predictor of ASD and ADHD; no prior studies have directly examined this prospectively. We investigated differences in longitudinal patterns of objectively measured motor activity during early development.

METHODS

Participants included 113 infants at high and low risk for ASD or ADHD. Continuous motion-based activity was recorded using tri-axial accelerometers at 12, 18, 24, and 36 months of age. At 36 months, participants were categorized into one of three outcome groups: ASD (n = 19), ADHD Concerns (n = 17), and Typically Developing (TD; n = 77). Group differences in trajectories of motor activity were examined in structured and semistructured contexts. Associations with behaviors relevant to ASD, ADHD, and general development were also examined.

RESULTS

In both structured and semistructured contexts, both the ASD and ADHD Concerns groups exhibited heightened activity relative to the TD group by 18 months; the ASD group exhibited higher activity than the ADHD Concerns group at 24-36 months in the structured context only. Attention/behavior regulation, nonverbal, and verbal development-but not social engagement-were differentially associated with objectively measured activity by outcome group across contexts.

CONCLUSIONS

Overactivity may be a shared, rather than distinct, precursor of atypical development in infants/toddlers developing ASD and concerns for ADHD, emerging as early as 18 months. Group differences in overactivity may be context-specific and associated with different underlying mechanisms.

Comparing estimates of physical activity in children across different cut-points and the associations with weight status

This study aimed to compare sedentary time (SED) and intensity-specific physical activity (PA) estimates and the associations of SED and PA with body mass index (BMI) and waist circumference (WC) using three different sets of cut-points in preschool-aged children. A total of 751 children (4.7 ± 0.9 years, boys 52.7%) wore an ActiGraph GT3X+BT accelerometer on their hip for 7 days (24 h). Euclidean norm -1 G with negative values rounded to zero (ENMO) and activity counts from vertical axis (VACounts) and vector magnitude (VMCounts) were derived. Estimates of SED and light, moderate, vigorous, and moderate-to-vigorous PA (MVPA) were calculated for commonly used cut-points by Hildebrand et al., Butte et al., and Evenson et al. Furthermore, the prevalence of meeting the PA recommendation, 180 min/day of which at least 60 min/day being MVPA, were assessed for the cut-points. Multilevel mixed analysis was used to examine associations of SED and PA with BMI and WC. In accordance with the results, SED and PA intensity estimates differed largely across cut-points (i.e., SED = 22-341 min/day; light PA = 52-257 min/day; moderate PA = 5-18 min/day; vigorous PA = 7-17 min/day; MVPA = 13-35 min/day), and the prevalence of children meeting the PA recommendation varied from 4% to 70%. Associations of SED and PA with BMI or WC varied between the cut-points. Our results indicate that SED and PA estimates in preschool-aged children between studies using these cut-points are poorly comparable. Methods facilitating accelerometer-derived PA estimate comparison between studies are highly warranted.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of Wrist Accelerometer Cut-Points for Classifying Physical Activity Intensity in Youth

Background

Wrist worn accelerometers are convenient to wear and provide greater compliance. However, methods to transform the resultant output into predictions of physical activity (PA) intensity have been slow to evolve, with most investigators continuing the practice of applying intensity-based thresholds or cut-points. The current study evaluated the classification accuracy of seven sets of previously published youth-specific cut-points for wrist worn ActiGraph accelerometer data.

Methods

Eighteen children and adolescents [mean age (± SD) 14.6 ± 2.4 years, 10 boys, 8 girls] completed 12 standardized activity trials. During each trial, participants wore an ActiGraph GT3X+ tri-axial accelerometer on the wrist and energy expenditure (Youth METs) was measured directly using the Oxycon Mobile portable calorimetry system. Seven previously published sets of ActiGraph cut-points were evaluated: Crouter regression vertical axis, Crouter regression vector magnitude, Crouter ROC curve vertical axis, Crouter ROC curve vector magnitude, Chandler ROC curve vertical axis, Chandler ROC curve vector magnitude, and Hildebrand ENMO. Classification accuracy was evaluated via weighted Kappa. Confusion matrices were generated to summarize classification accuracy and identify patterns of misclassification.

Results

The cut-points exhibited only moderate agreement with directly measured PA intensity, with Kappa ranging from 0.45 to 0.58. Although the cut-points classified sedentary behavior accurately (> 95%), classification accuracy for the light (3-51%), moderate (12-45%), and vigorous-intensity trials (30-88%) was generally poor. All cut-points underestimated the true intensity of the walking trials, with error rates ranging from 35 to 100%, while the intensity of activity trials requiring significant upper body and/or arm movements was consistently overestimated. The Hildebrand cut-points which serve as the default option in the popular GGIR software package misclassified 30% of the light intensity trials as sedentary and underestimated the intensity of moderate and vigorous intensity trials 75% of the time.

Conclusion

Published ActiGraph cut-points for the wrist, developed specifically for school-aged youth, do not provide acceptable classification accuracy for estimating daily time spent in light, moderate, and vigorous intensity physical activity. The development and deployment of more robust accelerometer data reduction methods such as functional data analysis and machine learning approaches continues to be a research priority.

mHealth Intervention for Motor Skills: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Children's motor skills are a critical foundation for physical activity. The objective was to determine the effectiveness and feasibility of a mobile app-based intervention delivered to parents to improve preschoolers' motor skills.

METHODS

This randomized controlled trial randomly assigned children to : (1) Motor Skills, including instructional lessons, peer modeling videos, behavioral scaffolding, and structured activities or 2) Free Play. Both groups received a 12-week app-based intervention informed by social cognitive theory to deliver 12 hours (12-minutes per day, 5× per week) of instruction. The children were aged 3 to 5 y; parents and children had no mobility impairments. The primary outcome variables were children's motor skills percentile score assessed with the Test of Gross Motor Development, third edition (TGMD-3) at baseline, end-of-intervention (week 12), and follow-up (week 24); and feasibility and acceptability.

RESULTS

Seventy-two children (4.0 ± 0.8 y) participated. Between baseline and week 12, children in the Motor Skills condition significantly improved total TGMD-3 percentile (+13.7 Motor Skills vs -5.3 Free Play, P < .01), locomotor skills percentile (+15.5 Motor Skills vs -4.8 Free Play, P < .01), and ball skills percentile (+8.3 Motor Skills vs -7.3 Free Play, P < .01) compared with children in the comparator group. Significant differences were sustained at follow-up (week 24). Adherence did not significantly differ between conditions (71% for Motor Skills; 87% for Free Play). Parents in both arms reported high scores on satisfaction, helpfulness, and ease of use.

CONCLUSIONS

Clinicians and educators may encourage parents to enhance their child's motor skills through structured at-home programs.

Parental Views on the Acceptability and Feasibility of Measurement Tools Used to Assess Movement Behaviour of Pre-School Children: A Qualitative Study

Movement behaviours (physical activity, sedentary behaviour, and sleep) are important for the health and development of pre-school children (aged 3-4 years). There is limited qualitative research examining the acceptability and feasibility of tools used to assess movement behaviours in pre-schoolers. This study explored parental views on various measurement tools in three deprived areas in England, UK (West Yorkshire, County Durham and Northumberland). The study consisted of a demonstration of the different tools (accelerometers, a diary and a questionnaire), directly followed by focus group discussions. Three focus group discussions with a total of eleven parents and carers were transcribed verbatim and analysed using thematic analysis. Findings revealed four main themes: (1) importance of contextual information when using any measurement tool (e.g., child illness, capturing different routines); (2) practical issues associated with devices (e.g., aversion to devices being attached directly to the skin of their child; concern of larger devices during sleep time); (3) encouraging children to wear a device (e.g., making devices attractive to children-'superpowers'); and (4) presentation of diaries and questionnaires (e.g., age-appropriate movement activities, preference for real-time recording over recall). Practical recommendations for the use of the tools to measure movement behaviours of pre-school children are provided.

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.