Prediction of energy expenditure and physical activity in preschoolers

24-hour movement behaviors and cognitive ability in preschool children: A compositional and isotemporal reallocation analysis

Research has supported the association between movement behaviors and cognitive ability in preschool children. However, most of the research has independently examined the various movement behaviors (e.g., physical activity, sedentary behavior, and sleep) without considering the dynamic composition of these behaviors in a 24-hour daily cycle. Therefore, this study aimed to explore the relationship between 24-hour movement behaviors and cognitive ability in preschool children. The participants were 191 Chinese preschool children from Zhuzhou aged 3-6 years. We measured light physical activity (LPA), moderate-to-vigorous physical activity (MVPA), and sedentary behavior (SB) using the Actigraph Accelerometers and evaluated the children's sleep time based on reports from parents and teachers. The Chinese version of the Wechsler Young Children Scale of Intelligence (C-WYCSI) was used to assess cognitive ability. Compositional analysis and isotemporal substitution were performed to examine the influence of 24-hour movement behaviors on children's cognitive ability. After controlling for demographics (e.g., age and sex), the composition of 24-hour movement behaviors was significantly associated with the verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full intelligence quotient (FIQ). Importantly, preschool children demonstrated greater cognitive behavior when time in MVPA replaced that spent in LPA, SB, or sleep than when time spent in LPA, SB, and sleep replaced that spent in MVPA within the 24-hour cycle. Physical activity engaged in a 24-hour daily cycle has a significant effect on cognitive ability in preschool children, with increased MVPA and LPA being associated with higher PIQ and FIQ and increased sleep being associated with lower VIQ, PIQ, and FIQ. Replacing time in SB and LPA with MVPA is promising for children's cognitive development.

Validity and reliability of the movement behaviour questionnaire child in Chinese preschoolers

Background

The Movement Behaviour Questionnaire Child (MBQ-C) was developed to measure physical activity, screen time, and sleep in preschool children, but the Chinese version lacked validation.

Methods

This cross-sectional study aimed to assess the validity and reliability of the open-ended version of the MBQ-C among Chinese preschoolers. Data were collected from 892 parents of children aged 0-5 years across 10 provinces via an online questionnaire. The MBQ-C includes items on physical activity, screen time, and sleep, and was validated against device-measured physical activity using accelerometers.

Results

Internal consistency was high, with Cronbach's alpha values ranging from 0.80 to 0.88 for different sections. Test-retest reliability showed moderate intraclass correlation coefficients (ICCs) between 0.52 and 0.72. Confirmatory factor analysis indicated good construct validity (CFI = 0.95). Moderate significant correlations were found between MBQ-C reported physical activity and device-measured moderate-to-vigorous physical activity (R = 0.35, p < 0.001).

Conclusion

The open-ended version of the MBQ-C demonstrates good validity and reliability in assessing movement behaviours among Chinese preschoolers. This tool is effective for proxy-reported measurements and can contribute to understanding and promoting healthy movement behaviours in early childhood.

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 Monitoring in Children in the 1-Year After 3 or More Days of Invasive Ventilation: Feasibility of Using Accelerometers

OBJECTIVES

To measure physical activity in a cohort of children who survived greater than or equal to 3 days of invasive ventilation.

DESIGN

Prospective cohort study (2018-2021).

SETTING

Quaternary children's hospital PICU.

PATIENTS

Children (2-17 yr old) without a preexisting tracheostomy who were ambulatory pre-illness and received greater than or equal to 3 days of invasive ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured duration and intensity of physical activity using hip- (< 6 yr old) or wrist- (≥ 6 yr old) worn ActiGraph GT3XP-BTLE accelerometers (ActiGraph, Pensacola, FL) for 7 days at three timepoints: hospital discharge, 3 months, and 12 months post-discharge. We measured duration of moderate or vigorous physical activity (MVPA) and nonsedentary activity, both characterized as percent of total awake wear time and total minutes per day. We categorized participants based on when they first attained a "high activity" day defined as greater than or equal to 60 minutes of MVPA or a day with percent of MVPA in the top quartile of all days measured. We evaluated 55 children of whom 43 (78%) had data from greater than or equal to 1 timepoint including 19 (35%) with data from all timepoints. Maximum daily MVPA increased across the three post-discharge timepoints (median, 16.0 min [interquartile range (IQR), 8.0-42.8 min], 48.3 min [27.8-94.3 min], and 68.4 min [34.7-111.0 min], respectively) as did maximum daily percent of awake wear time in MVPA (median, 4.3% [IQR, 2.8-9.0%], 10.1% [5.7-14.4%], and 11.1% [7.1-17.5%], respectively). Of the 43 participants, 27 achieved a high activity day: nine of 43 during the hospital discharge period, 14 of 43 during the 3 months post-discharge period, and four of 43 during the 12 months post-discharge period; 16 of 43 did not demonstrate high activity during the post-discharge year.

CONCLUSIONS

In the 1-year after PICU discharge measuring physical activity with accelerometers in children 2-17 years old is feasible. Furthermore, demonstration of variable recovery trajectories in our pilot cohort suggests it has potential to be an outcome measure in clinical trials.

Physical Activity, but Not Body Mass Index Is Associated With Blood Pressure in Young Children

PURPOSE

This study examined associations between physical activity (PA) and obesity with blood pressure (BP) in young children. Furthermore, a possible moderating effect of obesity status was examined.

METHODS

A cross-sectional study was completed with 121 children (3.96 [1.14] y). BP, weight, and height were measured, and body mass index (BMI) was calculated. Z scores were calculated for BMI, systolic, and diastolic values. Accelerometry measured time spent in PA intensities. Correlations and regressions examined relationships among PA intensities, BMI z scores, and BP z scores and to determine if obesity status moderated these relationships.

RESULTS

On average, the children spent 52 minutes per day in moderate-to-vigorous physical activity, 31% were considered overweight/obese, and 15% were considered hypertensive. After adjusting for confounders, participation in moderate, vigorous, and moderate-to-vigorous physical activity was related with lower systolic and diastolic BP z scores (P < .05). BMI z score was not related to BP values. Obesity status did not moderate the relationships between time spent in PA and BP.

CONCLUSIONS

Participation in PA, but not obesity, was related to lower BP levels in young children. The impact PA has on BP is the same regardless of obesity status. Thus, young children should be encouraged to be active in different intensities to benefit the cardiovascular system.

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.

Daily Physical Activity, Sports Participation, and Executive Function in Children

Importance

It is unclear whether daily physical activity and sports participation relate to executive function (EF) in children.

Objective

To explore associations between early-life physical activity, sports participation, and executive function in primary school children.

Design, Setting, and Participants

Data for this cohort study were collected from April 2006 to December 2017 from the Groningen Expert Center for Kids with Obesity (GECKO) Drenthe birth cohort, which includes Northern Dutch children. Preschool children aged 5 to 6 years and primary school children aged 10 to 11 years with valid EF, daily physical activity, and sports participation data were included in the analysis. Data were analyzed from May 2023 to February 2024.

Exposures

At ages 5 to 6 years, daily physical activity was measured with accelerometry. At ages 10 to 11 years, sports participation data were collected using the Short Questionnaire to Assess Health-Enhancing Physical Activity.

Main Outcomes and Measures

Executive function was assessed using the Behavior Rating Inventory of Executive Function at ages 10 to 11 years.

Results

A total of 880 children (470 female [53.4%]; mean [SD] age at EF measurement, 11.1 [0.4] years) were included. Moderate to vigorous physical activity at ages 5 to 6 years did not correlate with EF at ages 10 to 11 years (eg, Global Executive Composite [GEC]: β, 0.16; 95% CI, -0.21 to 0.53). Higher levels of light physical activity at ages 5 to 6 years were associated with poorer inhibitory control (β, 0.86; 95% CI, 0.24-1.47) and self-monitoring (β, 0.79; 95% CI, 0.09-1.48) at ages 10 to 11 years, while greater sedentary time was associated with better inhibitory control (β, -0.62; 95% CI, -1.08 to -0.16) and self-monitoring (β, -0.57; 95% CI, -1.09 to -0.06). Compared with children engaged in individual sports, team sports participants exhibited better overall EF (mean difference [SE], -3.03 [0.81]), behavior regulation (mean difference [SE], -3.39 [0.77]), and metacognition (mean difference [SE], -2.55 [0.81]). Children involved in both types of sports vs only individual sports had better EF (GEC: mean difference [SE], -2.66 [0.93]).

Conclusions and Relevance

In this cohort study of Dutch children, early-life moderate to vigorous physical activity was not associated with EF in middle childhood. Children participating in team sports at ages 10 to 11 years consistently exhibited superior EF compared with participants in individual sports.

Prospective Association Between 24-Hour Movement Behaviors and Fundamental Movement Skills in Chinese Preschoolers During the COVID-19 Pandemic: A Compositional and Reallocation Analysis

BACKGROUND

This prospective observation study explored the association between 24-hour movement behaviors and fundamental movement skills (FMS) in Chinese preschoolers during the COVID-19 pandemic.

METHODS

Four hundred and eighteen preschoolers (226 males; 4.0 [0.6] y old) from Zhuhai, China, completed the device-based physical activity (PA) and sedentary behavior measures, and sleep duration was reported by parents at baseline (October 2021 to December 2021). FMS was assessed using the Test of Gross Motor Development: Third Edition at 1-year follow-up (October 2022 to December 2022). The compositional analysis and isotemporal substitution were used.

RESULTS

Moderate to vigorous PA (MVPA) was positively associated with locomotor skills and ball skills (P < .05), and light physical activity was negatively associated with locomotor skills (P < .05) during the COVID-19 pandemic. FMS improvements were linked to the addition of MVPA at the expense of light physical activity, sedentary behavior, and sleep. The estimated detriments to FMS were larger in magnitude than the estimated benefits of time reallocation from MVPA to light physical activity, sedentary behavior, and sleep.

CONCLUSIONS

This study provides evidence about 24-hour movement behaviors and FMS during the COVID-19 pandemic and highlights the importance of participating in MVPA to improve preschoolers' FMS development during the COVID-19 era.

Are there associations between sedentary time inside and outside preschools with preschoolers' executive function?

Preschool children spend a large part of their day at school, and a large part of that time they spend in sedentary time. Although sedentary time negatively affects regions of the brain responsible for cognition, it is believed that the type of sedentary time performed can favor executive functions' performance. The present study explored the associations between sedentary time inside and outside preschools with executive function (EF) tasks in preschoolers. Seventy-three preschool children (60% girls; 55.0 ± 9.1 months of age) were objectively assessed for sedentary time and physical activity (PA) using accelerometers (wGT3X). EF was evaluated using the Go/No-Go paradigm through the Early Years Toolbox - YET. Go's inverse efficiency (IE) and the No-Go accuracy were analyzed. To establish possible associations between EF and sedentary time, a structural equation model was conducted after adjustments for sex, age, body mass index, and moderate-to-vigorous PA. A significant and positive association between sedentary time on weekend days and IE (b = 0.61; p < .001) was observed. The general model explained 52% of the variation in IE and 2.1% in the accuracy of No-Go. The sedentary time on weekend days seems to be related to worse EI. This result emphasizes a context-dependent association between time being sedentary and preschoolers' EF. Further investigations should focus on exploring the type of sedentary behavior children are engaged in different contexts.

The Cross-Sectional and Longitudinal Associations Between Adherence to 24-Hour Movement Behavior Guidelines and Bone Health in Young Children

BACKGROUND

Adherence to the World Health Organization's 24-hour movement behavior (24-HMB) guidelines is associated with various health outcomes. However, its relationship with bone mineral density (BMD) in young children has not been investigated. This study aimed to examine the cross-sectional and longitudinal associations between adherence to the 24-HMB guidelines and BMD in young children.

METHODS

A total of 120 children aged 3-5 years were recruited from three kindergartens in Changsha, Hunan, China. Physical activity (PA) was objectively measured using ActiGraph wGT3X-BT accelerometers, and BMD was assessed using the Sunlight Omnisense 7000P ultrasound device. Screen time (ST) and sleep duration (SD) were reported by parents. Logistic regression was used to analyze the associations between guideline adherence and BMD.

RESULTS

Only 5.5% of the participants met all three guidelines for PA, ST, and SD, while 16.5% did not meet any. In the cross-sectional analysis, young children who met both ST and SD guidelines (OR = 0.29, 95% CI: 0.09, 0.95) had a lower risk of insufficient BMD compared to those who met none. In the one-year cohort follow-up, young children who met the PA guideline at baseline (OR = 0.22, 95% CI: 0.07, 0.71), as well as those who met both the PA and ST guidelines (OR = 0.18, 95% CI: 0.04, 0.83) or all three (OR = 0.13, 95% CI: 0.03, 0.69), had a lower risk of insufficient BMD at one year.

CONCLUSIONS

Adherence to the 24-HMB guidelines may promote bone health in young children. Future research should prioritize achievable goals, such as limiting ST and ensuring adequate SD, while gradually increasing MVPA to optimize bone development.

Influence of physical activity home environment on fundamental movement skills development in Chinese preschoolers: mediating role of moderate-to-vigorous physical activity

Background

Research on how the physical activity home environment affects fundamental movement skills (FMS) in preschool children in China is limited. However, the role of moderate-to-vigorous physical activity (MVPA) in this relationship is still unclear. This study aims to analyze gender differences in FMS, explore associations between the physical activity home environment, MVPA, and FMS, and investigate MVPA's mediating role in these relationships.

Methods

We recruited 169 preschool children (95 boys, 74 girls; mean age 4.9 years) from four kindergartens in Hengyang, China. The Family Environment Scale on Motor Development for Preschool Urban Children (FESMPD) assessed physical activity home environment. Objective measurement of MVPA used ActiGraph wGT3-BT accelerometers. The Test of Gross Motor Development-3 (TGMD-3) evaluated FMS. Statistical analyses were conducted using the PROCESS macro in SPSS, with sociodemographic variables as controls.

Results

Boys exhibited significantly higher levels of MVPA, parenting style, locomotor skills, and object control skills compared to girls (P < 0.05). MVPA, parenting style, and FMS showed positive correlations (R = 0.355-0.568, P < 0.05). Similarly, MVPA was positively correlated with the physical activity home environment (β = 0.237-0.568, P < 0.05). Parenting style emerged as a significant predictor of children's MVPA levels (β = 0.956, P < 0.001), and MVPA was a predictor of the development ofFMS and its subdomains (β = 0.097-0.207, P < 0.05). Furthermore, MVPA partially mediated the relationship between parenting style and the development of FMS in preschool children. The physical environment was also a significant predictor of children's MVPA (β = 0.637, P < 0.05), and in turn, MVPA predicted the development of FMS and its subdomains (β = 0.188-0.343, P < 0.01). Notably, MVPA fully mediated the relationship between the physical environment and the development of FMS.

Conclusion

Overall, this study highlights the important roles of physical activity home environments and individual levels of MVPA in developing FMS in preschool children, noting significant gender differences. Parenting style greatly affects both MVPA and FMS development, while the physical environment fully mediates this relationship. Collaborative efforts among kindergartens, families, and communities are essential to support MVPA and improve FMS development.

Preschoolers' Moderate-to-Vigorous Physical Activity Measured by a Tri-Axial Accelerometer: Compliance with International Guidelines and Different Cut-Points

Background/Objectives: This study aimed to investigate the effect of the most frequently used accelerometer CoPs on the quantification of active preschoolers by weekday; and to analyze children's physical activity (PA) quantification using a vertical axis and vector magnitude (VM). Methods: A cross-sectional sample of 134 children (70 males) aged 3-5 years was studied. Height, body weight, and BMI were assessed. A tri-axial accelerometer was used for seven consecutive days of MVPA and sedentary behavior (SB). Data were analyzed using the three most used CoPs for active preschooler classification (Johansson, Butte, and Pate). A general linear model with repeated measures examined differences in PA and SB, and the agreements of all CoPs were analyzed using the Kappa index. Results: The CoPs adopted by Pate had the highest percentage of children classified as active for the weekdays (73.9%) and weekend (85.6%). The Johansson CoP classified all children as inactive. Furthermore, the prevalence of active boys was significantly higher than their female counterparts based on the Pate and Butte CoPs for the week and weekends. Conclusions: The lowest prevalence rates of active children were observed at the weekend based on all accelerometer CoPs, especially among girls. The choice of cut-points significantly affects the times calculated for different movement intensities.

Structured-unstructured activity behaviours on preschoolers' mental and physical health: a compositional and isotemporal reallocation analysis

This study analysed the relationship between the structured and unstructured activities of preschoolers and their mental and physical health, and also investigated the predicted changes in mental and physical health by reallocating activity time. This cross-sectional study was carried out with 324 preschoolers. Video recording and SOPARC activity observation system was used for the division of structured and unstructured activities. An accelerometer sensor was used to measure activity intensity. The SDQ psychological questionnaire was adopted to collect data on internalizing difficulties, externalizing difficulties, total difficulties and pro-social behaviours. Physical indices including body shape (height, weight, BMI), and physical fitness (upper and lower limb strength, flexibility, agility, and balance) were collected using Chinese toddler physical fitness measurement tools. Component data and isotemporal reallocation analyses were conducted using R Studio (Version 4.2). A total of 308 preschoolers (160 boys; aged 4.50 ± 0.93 years) were included in the data analysis. The activities composition, adjusted for sex, area, mental level (for mental indicators), or age (for physical indicators), was significantly correlated with various measurement indicators (p < 0.05). Specifically, structured (β=-0.87, p < 0.05) and unstructured (β=-1.24, p < 0.05) moderate-to-vigorous physical activity (MVPA) were significantly positive correlated with internalizing difficulties, while structured MVPA was significantly positively correlated with body shape (β = 2.17, p < 0.05). Replacing structured light physical activity (LPA) with 10 min of structured MVPA has a positive effect on internalizing difficulties (SMD=-1.28, 95%CI: -2.30 to -0.27) and body shape (SMD = 1.76, 95%CI: 0.37 to 3.15). When the total replacement time reaches 25 min, the benefits become even more pronounced. Structured and unstructured MVPA are both beneficial to preschoolers' mental and physical health, with the incorporation of MVPA for over 25 min in structured activities and supplementary unstructured MVPA yielding even greater benefits.

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.

Evaluation of indoor activities for moderate-to-vigorous physical activity in preschoolers

The study objectives were 1) to determine the feasibility and acceptability of indoor activities to achieve moderate-to-vigorous physical activity (MVPA) in preschoolers, and 2) compare MVPA estimates between direct observation (DO) and various accelerometry placements. In this cross-sectional study, 35 preschoolers (51% female, 54% 3-year-olds) performed six, 6-minute activities (dancing to video, balloon/bubbles, stationary exergame cycling, circuits, running-in-place, and cleaning up) in sequential order, facilitated by a trained staff member. Triaxial accelerometers (Actigraph Gt3×BT) at the ankle, waist, and wrist measured MVPA using age-specific cut-points. Total activity and MVPA time were quantified via DO of video recordings. Feasibility and acceptability were assessed via parent and child report. Preschoolers contributed 4339, 15-second epochs of accelerometry and DO data (~31.0 minutes/preschooler). Preschoolers achieved MVPA ≥ 50% of the time while engaging in balloon/bubbles, cycling, and circuits; but not while dancing to video (15%), running-in-place (48.5%), or cleaning up (8%). There were no differences in MVPA by age, sex, or between screen and non-screen activities. Parents and preschoolers reported most activities were feasible (≥4.0/5.0). Waist and ankle accelerometry had strong agreement with DO (ICCs range: 0.70-0.84) while wrist had fair to low agreement (ICCs: 0.22-0.58). Multiple indoor activities show promise to increase preschoolers' MVPA.

Leveraging an intensive time series of young children's movement to capture impulsive and inattentive behaviors in a preschool setting

Studying within-person variability in children's behavior is frequently hindered by challenges collecting repeated observations. This study used wearable accelerometers to collect an intensive time series (2.7 million observations) of young children's movement at school (N = 62, Mage = 4.5 years, 54% male, 74% Non-Hispanic White) in 2021. Machine learning analyses indicated that children's typical forward acceleration was strongly correlated with lower teacher-reported inhibitory control and attention (r = -.69). Using forward movement intensity as a proxy for impulsivity, we partitioned the intensive time series and found that (1) children modulated their behavior across periods of the school day, (2) children's impulsivity increased across the school week, and (3) children with greater impulsivity showed greater variability in behavior across days.

Compliance with the 24-hour movement behavior guidelines and the impact of sleep methods among toddler, preschool, and school-aged children enrolled in the Guelph Family Health Study

Canadian movement guidelines focused on physical activity (PA), sleep, and screen time support childhood development and reduce the risk of chronic disease. Accelerometers are often used to capture these behaviors; however, they are limited in their ability to record daytime sleep due to potential misclassification.

OBJECTIVES

The objectives of this study were to 1) determine the prevalence of children enrolled in the Guelph Family Health Study who met the guidelines and to 2) compare the impact of different sleep measurement methods.

DESIGN/METHODS

Toddlers (1.5-<3 years; n = 128; valid data for all movement behaviors, n = 70), preschoolers (3-<5 years; n = 143; valid data for all movement behaviors, n = 104), and school-aged (5-<6 years; n = 49; valid data for all movement behaviors, n = 31) children were included. Screen time and sleep habits were obtained through parental report and published normative data. PA and sleep were recorded using accelerometers (wGT3X-BT ActiGraph; right hip).

RESULTS

It was found that 66 % of toddler, 44 % of preschool, and 63 % of school-aged children met the screen time guidelines. Further, 63 % of toddler, 98 % of preschooler, and 80 % of school-aged children met PA guidelines. Sleep guideline compliance ranged from 3 % to 83 % in toddler, 27 % to 92 % in preschooler, and 32 % to 90 % in school-aged children. These proportions were found to be significantly different (Cochran's Q and McNemar's tests).

CONCLUSIONS

Nearly all children met PA guidelines. In contrast, less than half to two-thirds met screen time guidelines. Compliance with sleep guidelines varied substantially with measurement method, highlighting the need for standardization.

Sociodemographic Correlates of High Cardiovascular Health Across Childhood and Adolescence: A Prospective Study Among 2 Cohorts in the ECHO Consortium

BACKGROUND

This study seeks to characterize cardiovascular health (CVH) from early childhood to late adolescence and identify sociodemographic correlates of high CVH that serve as levers for optimizing CVH across early life.

METHODS AND RESULTS

Among 1530 youth aged 3 to 20 years from 2 cohorts in the ECHO (Environmental Influences on Child Health Outcomes) consortium, we first derived CVH scores on the basis of the Life's Essential 8 construct comprising 4 behavioral (nicotine use/exposure, physical activity, sleep, and diet) and 4 health factors (body mass index, blood pressure, non-high-density lipoprotein cholesterol, and fasting glucose) during early childhood (mean age, 3.5 years), middle childhood (8.0 years), early adolescence (13.3 years), and late adolescence (17.8 years). Next, we used generalized regression to estimate the probability of high (versus not high) CVH with respect to sociodemographic characteristics. Overall CVH score was stable across life stages: 81.2±7.6, 83.3±8.0, and 81.7±8.9 of 100 possible points in early childhood, middle childhood, and early adolescence, respectively. Accordingly, during these life stages, most children (63.3%-71.5%) had high CVH (80 to <100). However, CVH declined by late adolescence, with an average score of 75.5±10.2 and 39.4% high CVH. No children had optimal CVH (score=100) at any time. Correlates of high CVH include non-Hispanic White race and ethnicity, maternal college education, and annual household income >$70 000. These associations were driven by behavioral factors.

CONCLUSIONS

Although most youth maintained high CVH across childhood, the decline by late adolescence indicates that cardiovascular disease prevention should occur before the early teen years. Disparities in high CVH over time with respect to sociodemographic characteristics were explained by behavioral factors, pointing toward prevention targets.

Measuring Physical Activity in Children Who Do Not Walk and With Cerebral Palsy: An Exploratory Case Series

AIM

The purpose of this case series was to describe physical activity (PA) amount and intensity in the home and school environment. Accelerometers and heart rate (HR) monitors are reliable and valid measures of PA in children with cerebral palsy (CP) who can walk. There is limited research on PA measures in children with CP who cannot walk.

METHODS

Three 9-year-old boys with CP, Gross Motor Function Classification System levels IV and V, participated in a 1-week measurement period wearing waist- and wrist-worn triaxial accelerometers to measure PA counts and a wrist-worn HR monitor to measure PA intensity. PA intensity was calculated using an estimated HR max. Accelerometer counts were reported. Parents and school staff completed activity and eating journals.

RESULTS

Six days of PA and HR data were analyzed. Two participants spent more time in moderate/vigorous PA intensity during school compared to at home. Activities with greatest PA intensity included oral eating, communication, and social engagement. Higher activity counts were recorded from the wrist compared with the waist accelerometers. PA and eating journal adherence were high in both settings.

CONCLUSION

The findings provide preliminary data to evaluate PA amount and intensity in children with CP who have little walking ability. It is important to consider PA levels in daily activity for youth with CP when designing plans of care.

The "supercompensation" effect of children's lockdown during COVID-19: based on the analysis of changes in physical activity, sleep, and psychology

OBJECTIVE

To investigate the "supercompensation" effect of preschoolers during the coronavirus disease 2019 lockdown by comparing the changes in physical activity (PA), psychological, and sleep indicators before and after the lockdown.

METHODS

A total of 127 children (aged 3-6 years) were recruited. Before and after the lockdown, the children's PA levels were measured using the ActiGraph GT3X+, and their psychological and sleep indicators were measured using the Strengths and Difficulties Questionnaire (SDQ) and Child Sleep Habit Questionnaire (CSHQ), respectively.

RESULTS

Regarding PA, the children's total physical activity, low-intensity physical activity, and medium-intensity physical activity (MVPA) were higher after the lockdown than before the lockdown, with significant differences in MVPA (p < 0.05). Regarding psychology, the children's SDQ and multidimensional scores were better after the lockdown than before the lockdown, with a significant difference in SDQ scores (p < 0.05). Regarding sleep, the children's CSHQ scores were better after the lockdown than before the lockdown, with a highly significant difference in CSHQ scores (p < 0.01).

CONCLUSION

After lockdown, children's PA, psychological, and sleep effects were "supercompensated." In particular, the PA of preschoolers before, during, and after the lockdown may show a "baseline-inhibition-supercompensation" process.

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.

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.

Statistical analysis of actigraphy data with generalised additive models

There is a growing interest in the use of physical activity data in clinical studies, particularly in diseases that limit mobility in patients. High-frequency data collected with digital sensors are typically summarised into actigraphy features aggregated at epoch level (e.g., by minute). The statistical analysis of such volume of data is not straightforward. The general trend is to derive metrics, capturing specific aspects of physical activity, that condense (say) a week worth of data into a single numerical value. Here we propose to analyse the entire time-series data using Generalised Additive Models (GAMs). GAMs are semi-parametric models that allow inclusion of both parametric and non-parametric terms in the linear predictor. The latter are smooth terms (e.g., splines) and, in the context of actigraphy minute-by-minute data analysis, they can be used to assess daily patterns of physical activity. This in turn can be used to better understand changes over time in longitudinal studies as well as to compare treatment groups. We illustrate the application of GAMs in two clinical studies where actigraphy data was collected: a non-drug, single-arm study in patients with amyotrophic lateral sclerosis, and a physical-activity sub-study included in a phase 2b clinical trial in patients with chronic obstructive pulmonary disease.

A tendency toward evening chronotype associates with less healthy diet among preschoolers: cross-sectional findings from the DAGIS study

Study Objectives

Evidence suggests that adolescents and adults with a later chronotype have poorer sleep habits and are more susceptible to unhealthy behaviors, but little is known about these associations in younger children. The objective of the study was to (1) identify and compare individual chronotype tendencies among preschool-aged children and (2) investigate associations of sleep dimensions and chronotype with diet.

Methods

Participants were 636 3-6 years old (mean ± SD age: 4.74 ± 0.89 years, 49% girls) preschoolers from the cross-sectional Increased Health and Well-Being in Preschoolers (DAGIS) study in Finland. Sleep duration, sleep variability (in duration and midpoint), social jetlag, and midsleep on weekends adjusted for sleep debt (MSWEadj) were measured with 7-day actigraphy. Morning, intermediate, and evening chronotype tendencies were defined based on the lowest and highest 10th percentile cutoffs of MSWEadj. Food, energy, and macronutrient intake were assessed from 3-day records. Associations between sleep dimensions and diet were assessed with regression models.

Results

MSWEadj was 1:13 ± 14 minutes for morning (n = 64), 2:25 ± 28 minutes for intermediate (n = 560), and 3:38 ± 15 minutes for evening (n = 64) chronotype tendency. Children with an evening chronotype tendency had greater social jetlag and sleep variability. Having an evening chronotype tendency was associated with higher added sugar, higher sugary food consumption, and lower vegetable consumption compared to intermediate tendency types. A later chronotype (MSWEadj) was associated with higher sugary food consumption, as well as lower vegetable and fiber intake. Sleep duration, social jetlag, and sleep variability were not associated with diet.

Conclusions

Several less healthy sleep and diet behaviors were observed among children with later chronotypes. Future public health interventions aimed towards children would benefit from taking into account chronotype.

Energy Expenditure Prediction from Accelerometry Data Using Long Short-Term Memory Recurrent Neural Networks

The accurate estimation of energy expenditure from simple objective accelerometry measurements provides a valuable method for investigating the effect of physical activity (PA) interventions or population surveillance. Methods have been evaluated previously, but none utilize the temporal aspects of the accelerometry data. In this study, we investigated the energy expenditure prediction from acceleration measured at the subjects' hip, wrist, thigh, and back using recurrent neural networks utilizing temporal elements of the data. The acceleration was measured in children (N = 33) performing a standardized activity protocol in their natural environment. The energy expenditure was modelled using Multiple Linear Regression (MLR), stacked long short-term memory (LSTM) networks, and combined convolutional neural networks (CNN) and LSTM. The correlation and mean absolute percentage error (MAPE) were 0.76 and 19.9% for the MLR, 0.882 and 0.879 and 14.22% for the LSTM, and, with the combined LSTM-CNN, the best performance of 0.883 and 13.9% was achieved. The prediction error for vigorous intensities was significantly different (p < 0.01) from those of the other intensity domains: sedentary, light, and moderate. Utilizing the temporal elements of movement significantly improves energy expenditure prediction accuracy compared to other conventional approaches, but the prediction error for vigorous intensities requires further investigation.

Examining the relationship between meeting 24-hour movement behaviour guidelines and mental health in Chinese preschool children

Background

Limited research has explored the relationship between adhering to 24-h Movement Behaviour guidelines and mental health in Chinese preschool children. The objectives of this study encompassed two primary goals: (1) to investigate the adherence of preschool children in China to the 24-h Movement Behaviour guidelines; and (2) to analyze the relationship between fulfilling various combinations of these guidelines and mental health, identifying the most advantageous combination.

Methods

Utilizing a convenience sampling approach, this study included 205 preschool children (117 boys and 88 girls, average age 4.8 ± 0.51 years) from five kindergartens in Hengyang, Hunan Province. The physical activity (PA) and sedentary behaviour of preschool children were objectively assessed using waist-worn accelerometers, while sleep duration and screen time were reported by the children's parents. To evaluate mental health, the parent version of the internationally validated Strength and Difficulties Questionnaire (SDQ) was employed, which measures externalizing problems, internalizing problems, and prosocial behaviour. Employing Mplus 8.0 for Structural Equation Modeling analysis, while controlling for demographic variables, the study explored the connection between preschool children's mental health and their adherence to the 24-h Movement Behaviour guidelines.

Results

Worryingly, merely 14.6% of preschoolers met the recommended guidelines for all three aspects (PA, sleep duration, and screen time). Positive correlations were identified between meeting PA guidelines and displaying prosocial behaviour (β = 0.184; p < 0.05), while screen time adherence exhibited a negative correlation with externalizing problems (β = -0.207; p < 0.05). Similarly, there was a negative association between sleep duration adherence and externalizing problems (β = -0.191; p < 0.05). Meeting all three recommended guidelines was notably linked to enhanced prosocial behaviour (β = 0.464; p < 0.05), while following the screen time and sleep duration guidelines was negatively associated with externalizing problems (β = -0.246; p < 0.05).

Conclusion

This study underscores the limited adherence of Chinese preschoolers to the comprehensive 24-h Movement Behaviour guidelines. Noteworthy findings include the positive influence of PA on prosocial behaviour, alongside the significant roles that sleep duration and screen time play in mitigating externalizing problems within this age group. Alignment with the 24-h Movement Behaviour guidelines is associated with more favorable mental health indicators in preschoolers.

Isotemporal substitution effect of 24-hour movement behavior on the mental health of Chinese preschool children

The 24-h movement behavior of preschoolers comprises a spectrum of activities, including moderate-to-vigorous intensity physical activity (MVPA), light-intensity physical activity (LPA), screen-based sedentary behavior (SCSB), non-screen-based sedentary behavior (NSCSB), and sleep. While previous research has shed light on the link between movement behaviors and children's mental health, the specific impacts on the unique demographic of Chinese preschoolers remain underexplored. This study significantly contributes to the literature by exploring how 24-h movement behavior affects the mental health of preschoolers in a Chinese context. The study involved205 Chinese preschool children (117 boys and 88 girls) between the ages of 3 and 6 years wore accelerometers to measure their LPA, MVPA, and sedentary behavior (SB), while their parents reported the time spent on sleep and SCSB. The parents also completed the Strength and Difficulties Questionnaire to assess their children's mental health. The study used compositional regression and isotemporal substitution models to examine the relationship between the various components of 24-h movement behavior and mental health. The results showed that greater NCSSB compared to MVPA, LPA, sleep, and SCSB was associated with good prosocial behavior and lower scores on externalizing problems. This highlights the potential of NSCSB as a beneficial component in the daily routine of preschoolers for fostering mental well-being. Replacing 15 min of sleep and SCSB with 15 min of NSCSB was associated with a decrease of 0.24 and 0.15 units, respectively, in externalizing problems. Reallocating 15 min of sleep to NSCSB was linked to an increase of 0.11 units in prosocial behavior. There were no significant substitution effects between LPA and MVPA time with any other movement behavior on prosocial behavior and externalizing problems. Given the positive associations observed, further longitudinal studies are necessary to explore the link between 24-h movement behavior and mental health in preschool children.

24-Hour movement behaviors and executive functions in preschoolers: A compositional and isotemporal reallocation analysis

This cross-sectional study explored the relationship between 24-hour movement behaviors and executive function (EF) in preschool children. A total of 426 Han Chinese preschoolers (231 males; 3.8 ± 0.6 years old) from Zhuhai, Guangdong Province, China were selected from October 2021 to December 2021. Accelerometers were used to measure physical activity (PA) and sedentary behavior (SB), while sleep duration was obtained via a parent-report questionnaire. Components of EF (cognitive flexibility, inhibitory control, and working memory) were assessed using computerized behavioral tasks. The daily composition was significantly associated with inhibitory control and working memory. Inhibitory control improvements were linked to the addition of moderate-to-vigorous physical activity (MVPA) at the expense of SB and sleep. The reallocation between MVPA, SB, sleep, and light physical activity yielded a significant association with working memory.

Are low-income preschoolers physically active at preschool settings? A cross-sectional study

BACKGROUND

Preschools may provide opportunities for children to engage in physical activity (PA), to benefit their health, although little is known when concerning low-income preschoolers. This study aimed (1) to describe time spent in PA among low-income children during preschool hours and (2) to analyse how many children meet the PA recommendations during preschool hours.

METHODS

A total of 204 low-income preschoolers (4.51 ± 0.79 years) from João Pessoa/Brazil provided valid accelerometer (Actigraph, WGT3-X) data during the preschool period. Children were grouped in quartiles of PA in counts per minute, according to sex and age. The General Linear Model Univariate was used to examine the differences in PA intensities between the quartiles and the time spent in total PA (TPA) and moderate-to-vigorous PA (MVPA) by quartiles, according to age. An hour-by-hour description of children's PA was presented.

RESULTS

TPA during preschool hours ranged from 68.33% to 113.89% of the recommended and from 28.34% to 81.68% of the MVPA recommendations. Among 5-year-old children, those in the highest quartile met the PA recommendations. All children were more active outdoors than indoors. For the less actives, preschool time corresponded to 30% of the recommended daily MVPA.

CONCLUSION

The current results reinforce the importance of preschool settings for promoting preschoolers' PA and provide particularly important and useful information for tailoring preschool-based interventions focused on those who need it most. Strategies to increase children's MVPA should be prioritized during free-play time.

The Impact of an Acute Active Reading Intervention on Physical Activity Levels in Preschoolers: A Comparative Analysis

The purpose of this study was to examine the acute effects of an active reading intervention on physical activity (PA) levels in preschoolers. Participants were recruited from the 3-5-year-old classes at two preschools. A total of six classrooms and 37 children participated in three conditions: an active reading book read by a researcher (Act_R) trained in active play techniques, an active reading book read by a preschool classroom teacher (Act_T), and a book about health behavior read by both the researcher and the teacher (Sed_H). The order in which classes received each condition was randomized. The Actigraph accelerometer assessed PA. Motor skills were assessed with the Peabody Motor Development Scale, 2nd Edition. Participants spent significantly more time in sedentary behavior during the Sed_H condition compared to Act_R (p < 0.000) and Act_T (p < 0.008). Participants spent significantly more time in MVPA during Act_R compared to Act_T (p = 0.030), Act_T compared to Sed_H (p < 0.001), and Act_R compared to Sed_H (p < 0.001). The amount of MVPA participation within the active reading sessions was not dependent upon the level of fundamental motor skill competence. Active reading books may provide a feasible method to incorporate physical activity and active play into the preschool day.

Sitting Less for Success: Reducing Sedentary Behaviors to Increase Kindergarten Achievement

BACKGROUND

Physical activity (PA) improves outcomes, but disadvantaged children typically experience more sedentary behavior (SB). This study explored movement, executive function (EF) health, and academic achievement (AA) for economically disadvantaged kindergarteners.

METHODS

Children in 2 classrooms (n = 16; n = 7) wore wrist-based accelerometers to assess PA/SB during the school day. Independent t-tests and analysis of variance analyzed mean group differences in PA/SB and EF/AA, and correlations explored AA and EF associations.

RESULTS

The movement-based class spent significantly less time in SB compared to the contemporary class (t = 2.552, g = 1.115), made greater reading (t = -2.611) and math (t = .967) gains, and had better EF (t = .012). There were significant negative correlations between SB and math (r = -.534) and reading (r = -.592), but no significant relationships with EF.

IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY

Schools should consider methods to decrease time spent in SB at lower-SES schools, which is financially feasible and less time-consuming than programs to increase PA.

CONCLUSION

Decreased SB time was associated with better AA. More research is needed to determine whether interventions to decrease time spent in SB at school improve academic outcomes in disadvantaged children.

Comparison of actigraphy-measured and parent-reported sleep in association with weight status among preschool children

This study compared weekday and weekend actigraphy-measured and parent-reported sleep in relation to weight status among preschool-aged children. Participants were 3-6 years old preschoolers from the cross-sectional DAGIS-study with sleep data for ≥2 weekday and ≥2 weekend nights. Parents-reported sleep onset and wake-up times were gathered alongside 24 h hip-worn actigraphy. An unsupervised Hidden-Markov Model algorithm provided actigraphy-measured night time sleep without the guidance of reported sleep times. Waist-to-height ratio and age-and-sex-specific body mass index characterised weight status. Comparison of methods were assessed with consistency in quintile divisions and Spearman correlations. Associations between sleep and weight status were assessed with adjusted regression models. Participants included 638 children (49% girls) with a mean ± SD age of 4.76 ± 0.89. On weekdays, 98%-99% of actigraphy-measured and parent-reported sleep estimates were classified in the same or adjacent quintile and were strongly correlated (rs  = 0.79-0.85, p < 0.001). On weekends, 84%-98% of actigraphy-measured and parent-reported sleep estimates were respectively classified and correlations were moderate to strong (rs  = 0.62-0.86, p < 0.001). Compared with actigraphy-measured sleep, parent-reported sleep had consistently earlier onset, later wake-up, and greater duration. Earlier actigraphy-measured weekday sleep onset and midpoint were associated with a higher body mass index (respective β-estimates: -0.63, p < 0.01 and -0.75, p < 0.01) and waist-to-height ratio (-0.004, p = 0.03 and -0.01, p = 0.02). Though the sleep estimation methods were consistent and correlated, actigraphy measures should be favoured as they are more objective and sensitive to identifying associations between sleep timing and weight status compared with parent reports.

Estimating Physical Activity and Sleep using the Combination of Movement and Heart Rate: A Systematic Review and Meta-Analysis

The purpose of this meta-analysis was to quantify the difference in physical activity and sleep estimates assessed via 1) movement, 2) heart rate (HR), or 3) the combination of movement and HR (MOVE+HR) compared to criterion indicators of the outcomes. Searches in four electronic databases were executed September 21-24 of 2021. Weighted mean was calculated from standardized group-level estimates of mean percent error (MPE) and mean absolute percent error (MAPE) of the proxy signal compared to the criterion measurement method for physical activity, HR, or sleep. Standardized mean difference (SMD) effect sizes between the proxy and criterion estimates were calculated for each study across all outcomes, and meta-regression analyses were conducted. Two-One-Sided-Tests method were conducted to metaanalytically evaluate the equivalence of the proxy and criterion. Thirty-nine studies (physical activity k = 29 and sleep k = 10) were identified for data extraction. Sample size weighted means for MPE were -38.0%, 7.8%, -1.4%, and -0.6% for physical activity movement only, HR only, MOVE+HR, and sleep MOVE+HR, respectively. Sample size weighted means for MAPE were 41.4%, 32.6%, 13.3%, and 10.8% for physical activity movement only, HR only, MOVE+HR, and sleep MOVE+HR, respectively. Few estimates were statistically equivalent at a SMD of 0.8. Estimates of physical activity from MOVE+HR were not statistically significantly different from estimates based on movement or HR only. For sleep, included studies based their estimates solely on the combination of MOVE+HR, so it was impossible to determine if the combination produced significantly different estimates than either method alone.

Children's Energy Intake Generally Increases in Response to the Energy Density of Meals but Varies with the Amounts and Types of Foods Served

BACKGROUND

Food energy density (ED; kcal/g) is positively related to energy intake in numerous studies. A recent secondary analysis proposed that when the ED of consumed food is above a breakpoint, adults sense calories and adjust meal size to minimize overconsumption.

OBJECTIVES

We conducted a secondary analysis of measured intakes in preschool children to assess how meal energy intake was related to meal ED as well as to meal portions, eating occasions, and menus.

METHODS

We analyzed weighed intakes from 6355 meals served to 94 children aged 3 to 5 y in 2 randomized crossover trials. We provided children with all their daily food and milk for multiple periods of 5 consecutive days in their usual childcare setting. We used linear mixed models with repeated measures to analyze the effects on energy intake of meal ED and meal weight, either as served or as consumed.

RESULTS

Energy intake at meals was related to the ED and portions of served food and also to the ED and weight of consumed food (all P < 0.0001). Energy intake was also significantly affected by the eating occasion and the foods served on the menus. Children selectively ate higher-ED items, which were served in smaller amounts than lower-ED options. Meal energy intake was curvilinear across consumed ED; it initially increased (slope: 113 ± 2 kcal/ED unit) but decreased at higher-ED meals (deceleration: -11 ± 1 kcal/ED unit2) without evidence of a clear breakpoint. This trajectory may be attributable to the relatively limited portions of higher-ED foods that were served.

CONCLUSIONS

Children's energy intake generally increased with greater ED; at higher-ED meals, however, energy intake decreased in a curvilinear manner without a clear breakpoint. This reduction in intake at higher ED could be explained by meal-related factors such as the portions served rather than by sensitivity to meal energy content. This study was registered at clinicaltrials.gov as NCT03010501 and NCT03242863.

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.

Measurement of Physical Activity by Actigraphy in Infants and Young Children with Pulmonary Arterial Hypertension

OBJECTIVE

To evaluate the feasibility, tolerability, and adherence with wearable actigraphy devices among infants and children with pulmonary arterial hypertension (PAH).

STUDY DESIGN

This multicenter, prospective, observational study included children ages 0-6 years with and without PAH. Participants wore the ActiGraph wGT3X-BT on the hip and FitBit Inspire on the wrist during waking hours for 14 days. Steps, vector magnitude counts per minute, activity intensity, heart rate, and heart rate variability were compared between groups.

RESULTS

Forty-seven participants (18 PAH, 29 control) were enrolled from 10 North American sites. PAH patients were mostly functional class II (n = 16, 89%) and treated with oral medications at the time of enrollment. The number of wear days was not significantly different between the groups (ActiGraph: 10 [95% CI: 5.5, 12.2] in PAH vs 8 [4, 12] in control, P = .20; FitBit 13 [10, 13.8] in PAH vs 12 [8, 14] in control, P = .87). Complete data were obtained in 81% of eligible ActiGraph participants and 72% of FitBit participants. PAH participants demonstrated fewer steps, lower vector magnitude counts per minute, more sedentary activity, and less intense physical activity at all levels compared with control participants. No statistically significant differences in heart rate variability were demonstrated between the 2 groups.

CONCLUSIONS

Measurement of physical activity and other end points using wearable actigraphy devices was feasible in young children with PAH. Larger studies should determine associations between physical activity and disease severity in young patients with PAH to identify relevant end points for pediatric clinical trials.

A Comparison of Sleep Duration Accuracy Between Questionnaire and Accelerometer in Middle Childhood

Purpose Healthy sleep is vital to children's well-being, and assessing sleep efficiently and accurately can help understand children's lifestyles. Due to the difficulty in objectively measuring sleep duration using wearable sensors in large-scale surveys of children, self-administered questionnaires are often used in Japan; however, their accuracy is uncertain. We evaluated and compared the accuracy of questionnaire-based sleep times to those of wearable sensors. Methods This observational study was conducted between November 2019 and January 2020. A self-administered questionnaire on lifestyle habits and ActiGraph GT3X+ (ActiGraph, Inc., Pensacola, USA) accelerometer data were collected from 40 fourth-grade elementary school students in Kagawa Prefecture, Japan. We analyzed measurements for 256 days out of 280 days (40 persons × 7 days) after excluding days when the rate of wearing the accelerometer was < 90%. Results The median sleep duration per accelerometry was 453 minutes, and the median time in bed was 519 minutes. Questionnaire-based time in bed was 11 minutes longer, with relatively high inter-individual variability. The difference in bedtime was 26 minutes earlier, and wake-up time was 12 minutes earlier for the questionnaire. The average sleep efficiency was 87.4%, and one-third of the children had sleep efficiency < 85%. Conclusion The difference in sleep duration by questionnaire compared to accelerometry was approximately 10 minutes, suggesting the questionnaire may determine sleep duration with accuracy.

Biological, behavioral, and social correlates of executive function in low-income preschoolers: Insights from the perspective of the networks

Behavioral, biological, and social correlates may be related to the association between executive function (EF) and physical activity (PA), when considering such variables as an integrated and non-linear system. Thus, the aim of the present study was to investigate the relationships between EF, PA and associated correlates in low-income preschoolers according to a network perspective. Thus, 142 preschoolers of both sexes, age 3-to-5-years-old (51% girls) were analyzed. Light, moderate and vigorous PA, cardiorespiratory fitness (CRF), body mass index, family income, preterm birth, presence of siblings, presence of other children at home and the child's primary caregiver were assessed. Our results showed that EF was positively associated with age (b = 0.47), child's primary caregivers (b = 0.37), moderate PA (b = 0.30) and CRF (b = 0.25). Negative associations were seen with preterm birth (b = -0.50), vigorous PA (b = -0.34), presence of other children at home (b = -0.25), and sex (b = -0.33). The network's centrality indicators highlighted preterm birth and moderate PA as the most important variables in the network. Future interventions aiming to increase low-income preschoolers' EF should focus on increasing moderate PA, with special attention to preterm children.

A prospective analysis of physical activity and mental health in children: the GECKO Drenthe cohort

BACKGROUND

Mental health problems in young people have become a global health burden. The positive effects of physical activity on mental health in adults are well known but still not clear in children. The aim of this study was to investigate to what extent physical activity in early childhood would affect mental health in middle childhood.

METHODS

From the Dutch GECKO Drenthe birth cohort, 850 children (51.5% boys) were enrolled in this analysis. Physical activity and sedentary time were measured at age 5-6 using ActiGraph GT3X. Mental health was assessed using the Strengths and Difficulties Questionnaire (SDQ) at age 5-6 and age 10-11. Multiple linear regression models were used to estimate the associations between physical activity, sedentary time and SDQ subscales, stratified by gender, adjusting for age, BMI, maternal education level, family size, accelerometer wear time and season, and additionally adjusting for SDQ scores at age 5-6 to take tracking of mental health over time into account.

RESULTS

Greater physical activity volume at age 5-6 was associated with lower peer problems scores at age 10-11 in boys and girls. An increase in MVPA was associated with lower peer problems scores in boys (b = -0.445, -0.713 to -0.176) and girls (b = -0.354, -0.601 to -0.107), however, increased sedentary time was linked to higher peer problems scores in boys (b = 1.18, 0.455 to 1.906) and girls (b = 0.870, 0.191 to 1.550). For hyperactivity, higher levels of physical activity volume and MVPA were associated with higher hyperactivity scores in boys. Increased sedentary time was related to lower hyperactivity scores in boys. Further adjustment for SDQ scores at age 5-6 attenuated associations between physical activity and hyperactivity in boys but hardly changed the relationships with peer problems. No significant associations between physical activity and other SDQ subscales or total difficulties scores were observed, neither in boys nor in girls.

CONCLUSIONS

Children who are more physically active at age 5-6 have fewer peer problems at age 10-11, and for boys, greater activity levels at age 5-6 could be an indicator of hyperactivity at age 10-11.

The relationship in early childhood body composition and physical activity levels regarding fundamental motor skill development

BACKGROUND

Fundamental motor skills (FMS) are considered essential for sport participation and might be deficit in obese children. While evidence indicates that physical activity (PA) levels impact motor skill development, the relationship between body composition, PA, and motor competence, particularly in early childhood, is not thoroughly understood. We aimed to determine if PA, fat mass (FM), and fat-free mass (FFM) are predictors of FMS.

METHODS

Preschoolers (n = 47) from two preschools were assessed for FMS, PA, and body composition. Peabody Developmental Motor Scales (PDMS-2) subscale scores were used to assess FMS. PA was assessed with a wrist-worn accelerometer for five days during school. FM and FFM were measured with foot-to-foot bioelectrical impedance.

RESULTS

Linear regressions indicate significant models for stationary skills (SS) (F = 4.57, p = .004) and object manipulation skills (OMS) (F = 4.66, p = .003). FFM was the only significant predictor of SS (t = 3.98, p < .001) and OMS (t = 3.50, p = .001). FM and all intensities of PA were nonsignificant predictors in all models.

CONCLUSIONS

These results indicate that interventions that target improving or maintaining FFM may improve FMS.

Ultra-processed food consumption and BMI-Z among children at risk for obesity from low-income households

OBJECTIVE

To evaluate the association between baseline ultra-processed food consumption in early childhood and child BMI Z-score over 36 months.

METHODS

We conducted a prospective cohort analysis as a secondary data analysis of the Growing Right Onto Wellness randomised trial. Dietary intake was measured via 24-h diet recalls. The primary outcome was child BMI-Z, measured at baseline and at 3-, 9-, 12-, 24- and 36-month timepoints. Child BMI-Z was modelled using a longitudinal mixed-effects model, adjusting for covariates and stratifying by age.

RESULTS

Among 595 children, median (Q1-Q3) baseline age was 4.3 (3.6-5.0) years, 52.3% of the children were female, 65.4% had normal weight, 33.8% were overweight, 0.8% were obese and 91.3% of parents identified as Hispanic. Model-based estimates suggest that, compared with low ultra-processed consumption (300 kcals/day), high ultra-processed intake (1300 kcals/day) was associated with a 1.2 higher BMI-Z at 36 months for 3-year-olds (95% CI = 0.5, 1.9; p < 0.001) and a 0.6 higher BMI-Z for 4-year-olds (95% CI = 0.2, 1.0; p = 0.007). The difference was not statistically significant for 5-year-olds or overall.

CONCLUSIONS

In 3- and 4-year-old children, but not in 5-year-old children, high ultra-processed food intake at baseline was significantly associated with higher BMI-Z at 36-month follow-up, adjusting for total daily kcals. This suggests that it might not be only the total number of calories in a child's daily intake that influences child weight status, but also the number of calories from ultra-processed foods.

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.

Application of Life's Essential 8 to assess cardiovascular health during early childhood

PURPOSE

Assess cardiovascular health (CVH) during early childhood using the American Heart Association's recently updated construct, Life's Essential 8 (LE8); examine concordance in CVH status per LE8 versus Life's Simple 7 (LS7); and identify perinatal correlates of high CVH per LE8.

METHODS

We applied LE8 and LS7 to data from 305 children aged 4-7 years in Denver, CO; estimated % low, moderate, high, and optimal CVH; assessed concordance in CVH status based on LE8 and LS7 using contingency tables; and used multivariable logistic regression to identify early-life correlates of high CVH per LE8.

RESULTS

Average age of children was 4.7 ± 0.6 years, 44.6% were female. No participants had low or optimal CVH, 43.9% had high, and 56.1% had moderate CVH per LE8, whereas 33.4% had high and 66.6% had moderate CVH per LS7. Twenty-two percent had high CVH based on both constructs. Correlates of high CVH were maternal prenatal diet quality (odds ratioHealthy Eating Index score>vs. ≤57 = 1.90 [1.12, 3.21]) and child age (odds ratioper 1 year = 1.58 [1.04. 2.42]).

CONCLUSIONS

LE8 yielded higher prevalence of high CVH than LS7 during early childhood, though there is modest concordance between the two constructs. Maternal diet is a potential modifiable target to optimize early-life CVH.

How Teacher Verbal Prompting and Demonstrated Modeling Correlate to Preschooler's Physical Activity Levels

BACKGROUND

Teacher-led strategies targeting verbal prompting and demonstrated modeling can increase preschoolers' physical activity levels; however, it is unknown which strategy promotes higher levels. The purpose of this study was to explore whether teacher verbal prompting or demonstrated modeling elicits higher levels of physical activity among preschoolers.

METHODS

Participants included 117 (56 females and 61 males; mean = 3.77 y) preschoolers who were observed for 3 days during regular preschool instructions. The System for Observing Student Movement in Academic Routines and Transitions observation system assessed verbal prompting and demonstrated modeling of the teachers, and preschoolers wore an ActiGraph accelerometer to measure physical activity.

RESULTS

The multivariate analysis of variance results showed a significant difference for verbal prompting (P < .001), demonstrated modeling (P = .032), light physical activity (P < .001), and moderate to vigorous physical activity (MVPA; P < .001) between segments of the preschool day. A stepwise linear regression showed that preschooler's MVPA (P = .005) and light physical activity and MVPA (P = .036) were significantly related to demonstrated modeling, but not verbal prompting. During indoor time, light physical activity and MVPA were highest during large group, work time, and morning group, where teacher demonstrated modeling occurred the most.

CONCLUSIONS

Teacher demonstrated modeling had a significant relationship to preschoolers' MVPA and light physical activity levels, while teacher verbal prompting did not.

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.

Promoting Positive Health Outcomes in an Urban Community-Based Physical Activity Intervention for Preschool Aged Children on the Autism Spectrum

While there is wide consensus regarding the importance of early intervention, health is rarely considered within priorities. Twenty-five children on the autism spectrum (M_age = 4.67, SD = 0.82) participated in a 12-week physical activity intervention. Primary objective was to examine impact of a physical activity intervention on physical activity, fitness and motor competence. Secondary objective was to examine associations between motor behavior and ASD symptoms. Ball skills (p < .001) and isometric push-up performance (p = .02) improved. Autism symptoms were associated with motor skills (r > -  .49, p < .05). Study outcomes provide new knowledge regarding design, delivery, and measures for early interventions targeting health disparities in young children on the autism spectrum.

Correlates of the Physical Activity Decline during Childhood

PURPOSE

This study aimed to describe longitudinal trends in children's moderate-to-vigorous physical activity (MVPA) and to investigate associations with individual, familial, and school characteristics.

METHODS

A sample of 341 Portuguese children age 5-10 yr (173 girls) from six age cohorts was followed over 3 yr using a mixed-longitudinal design. Physical activity, body mass index (BMI), gross motor coordination, and musculoskeletal fitness were assessed annually. Information on socioeconomic status and school characteristics was collected and analyzed with mixed models.

RESULTS

MVPA shows a similar declining trend in both sexes, but on average, boys exceeded the World Health Organization recommendations of 60 min·d -1 . The best model showed that boys spend, on average, more time in MVPA than girls. Children with lower BMI are less prone to the decline in MVPA, whereas higher levels of musculoskeletal fitness were associated with lower declines in MVPA. Of all school characteristics, only playground dimension was related to MVPA decreasing trajectories.

CONCLUSIONS

MVPA systematically declines from 5 to 10 yr of age in both boys and girls, but boys remained more active than girls across the age range. The best predictors of MVPA decline are sex, BMI, musculoskeletal fitness, and school playground dimension.

Operationalization, measurement, and health indicators of sedentary behavior in individuals with cerebral palsy: a scoping review

PURPOSE

To explore the operationalization and measurement of sedentary behavior (SB) in individuals with cerebral palsy (CP).

MATERIALS AND METHODS

We searched five databases from 2011 to 2020 for primary studies of experimental, qualitative, longitudinal, or observational designs measuring SB or postures typically characterized as sedentary (sitting, reclining, lying).

RESULTS

We screened 1112 citations and selected 47 studies. SB was operationalized through muscle activation, energy expenditure or oxygen consumption in typically sedentary postures (n = 9), and through thresholds and postures used by accelerometers, activity monitors, and a questionnaire to measure time spent in SB (n = 25). Seven out of the eight studies that measured energy expenditure found ≤1.5 metabolic equivalents of task (METs) for sitting and lying. While different accelerometer thresholds were used to measure SB, the behavior (SB) was consistently operationalized as sitting and lying. Little consistency existed in the subpopulation, instruments and cut-points for studies on validity or reliability of tools for measuring SB (n = 19).

CONCLUSIONS

Sitting and lying are considered sedentary postures, which is defined as ≤1.5 METs in individuals with CP. There is variability in the tools used to measure SB in individuals with CP. Therefore, consensus on the definition and reporting of SB is needed.Implications for rehabilitationAlthough sedentary behavior (SB) is increased in individuals with cerebral palsy (CP) compared to the typically developing population, there is no standard definition for SB for these individuals; this makes it difficult to synthesize data across studies.Sitting and lying are ≤1.5 METs in individuals with CP, suggesting we only need to measure posture to show change in SB.The commonly used accelerometer cut-point in the typically developing population of ≤100 counts per minute generally has excellent reliability across multiple devices in ambulatory children with CP.

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

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

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.