The Dilemma of Analyzing Physical Activity and Sedentary Behavior with Wrist Accelerometer Data: Challenges and Opportunities

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.

Accelerometry-assessed daily physical activity and compliance with recommendations in Spanish children: importance of physical education classes and vigorous intensity

Background

Physical activity (PA) is associated with numerous health benefits. Vigorous PA (VPA) may have a greater impact on public health than lower-intensity PA. The incorporation of a specific recommendation on VPA could complement and improve existing recommendations for average daily moderate-vigorous PA (MVPA). Physical education classes could have a positive impact on children's adherence to average daily physical activity recommendations. The aim was to investigate the association between MVPA and VPA in children, as well as adherence to recommendations, and obesity and the presence of physical education classes.

Methods

A cross-sectional study of physical activity was conducted in a sample of 8 and 9-year-old children in Andalusia (Spain). GENEActiv accelerometers were used, placed on the non-dominant wrist for at least eight consecutive days (24-h protocol). School days with and without physical education class, and weekend days were defined. ROC curves were used to calculate the threshold associated with obesity for average daily MVPA and VPA for recommendations.

Results

A total of 360 schoolchildren were included in the analyses (184 girls). An average of 7.7 (SD 1.4) valid days per participant were evaluated, with 19.9 (SD 10.5) and 11.4 (SD 5.1) minutes of VPA performed by boys and girls respectively. 25.8% of the participants were classified with central obesity. The optimal threshold determined with ROC analysis was 12.5 and 9.5 minutes of average daily VPA for boys and girls, respectively (RecVPA), and 75 minutes of average daily MVPA for both sexes (RecMVPA). The RecVPA showed stronger association with obesity. On school days with physical education class, compared to days without this class, children showed increased VPA and MVPA engagement and better compliance with recommendations, with smaller differences in adherence according to sex or obesity.

Conclusions

On days with physical education class, more physical activity was accumulated at all intensities and greater adherence to the recommendations than on days without this class. VPA had a stronger correlation with the absence of obesity than lower-intensity activity. It was also observed that boys were physically more active and had higher adherence to the recommendations than girls.

Agreement between self-reported and objectively assessed physical activity among out-of-hospital cardiac arrest survivors

BACKGROUND

Low level of physical activity is a risk factor for new cardiac events in out-of-hospital cardiac arrest (OHCA) survivors. Physical activity can be assessed by self-reporting or objectively by accelerometery.

AIM

To investigate the agreement between self-reported and objectively assessed physical activity among OHCA survivors HYPOTHESIS: Self-reported levels of physical activity will show moderate agreement with objectively assessed levels of physical activity.

METHOD

Cross-sectional study including OHCA survivors in Sweden, Denmark, and the United Kingdom. Two questions about moderate and vigorous intensity physical activity during the last week were used as self-reports. Moderate and vigorous intensity physical activity were objectively assessed with accelerometers (ActiGraph GT3X-BT) worn upon the right hip for 7 consecutive days.

RESULTS

Forty-nine of 106 OHCA survivors answered the two questions for self-reporting and had 7 valid days of accelerometer assessment. More physically active days were registered by self-report compared with accelerometery for both moderate intensity (median 5 [3:7] vs. 3 [0:5] days; p < 0.001) and vigorous intensity (1 [0:3] vs. 0 [0:0] days; p < 0.001). Correlations between self-reported and accelerometer assessed physical activity were sufficient (moderate intensity: rs  = 0.336, p = 0.018; vigorous intensity: rs  = 0.375, p = 0.008), and agreements were fair and none to slight (moderate intensity: k = 0.269, p = 0.001; vigorous intensity: k = 0.148, p = 0.015). The categorization of self-reported versus objectively assessed physical activity showed that 26% versus 65% had a low level of physical activity.

CONCLUSION

OHCA survivors reported more physically active days compared with the results of the accelerometer assessment and correlated sufficiently and agreed fairly and none to slightly.

Adherence to the WHO recommendation of three weekly days of vigorous intensity activities in children: an accelerometry study of vigorous physical activity bouts

Background

The World Health Organization (WHO) recommends that children and adolescents incorporate vigorous intensity activities (VIAs) at least three days a week. This recommendation has not been sufficiently studied using objective methods, such as accelerometry. Physical education classes and extracurricular sports activities are optimal opportunities for compliance with this recommendation.

Objective

To identify VIAs through bouts of vigorous physical activity (VPA-Bouts) evaluated with accelerometry and, with this, to know the compliance with the recommendation on VIAs.

Methods

A cross-sectional study of the habitual physical activity of 353 children (8-9 years old) was carried out using accelerometry and participation in organized extracurricular sports activities was asked through a questionnaire. School days with and without physical education class, weekends, and the average weekly day were identified, as well as school time and out-of-school time. A VPA-Bout was defined as an interval of at least 60 minutes with a proportion of VPA of at least 16.7% in boys and 12.5% in girls (10.0 and 7.5 minutes/hour of VPA, respectively).

Results

The average daily time in organized extracurricular sports activities declared by questionnaire and the average daily duration of the VPA-Bouts evaluated with accelerometers in the extracurricular period was 21.3 (SD 19.8) and 23.9 (SD 31.2) minutes, respectively, in boys, whereas, in girls it was 20.2 (SD 17.4) and 11.0 (SD 16.9) minutes, respectively. In school time including a physical education class, there was a higher proportion of VPA-Bouts than without these classes (with: 28.6%, without: 2.1%, p < 0.001). Children who reported at least three weekly hours of organized extracurricular sports activities accumulated a higher proportion of school afternoons with VPA-Bouts than those with fewer weekly hours of this type of activities (≥3 hours/week: 27.5%, <3 hours/week: 9.3%, p < 0.001). On the weekend, boys who reported at least three weekly hours of organized extracurricular sports activities performed more VPA-Bouts than those participating in less weekly hours, while in girls no significant differences were observed (weekend; boys, ≥3 hours/week: 26.0%, <3 hours/week: 9.0%, p < 0.001; girls: 8.3%, 8.0%, p = 0.917). Compliance with the recommendation to incorporate VIAs at least three days a week was 23.8%. Children who reported at least three weekly hours of extracurricular sports activities achieved higher compliance than those who reported fewer extracurricular activities (≥3 hours/week: 35.1%, <3 hours/week: 12.7%, p < 0.001). Additionally, boys showed higher compliance rates than girls (boys: 32.9%, girls: 15.3%, p < 0.001).

Conclusion

One in every four children met the WHO recommendation to incorporate VIAs at least three days a week, as evaluated by accelerometry. Physical education classes and extracurricular organized sports activities contributed to compliance with this recommendation.

Incorporating Wearable Technology for Enhanced Rehabilitation Monitoring after Hip and Knee Replacement

Osteoarthritis (OA) poses a growing challenge for the aging population, especially in the hip and knee joints, contributing significantly to disability and societal costs. Exploring the integration of wearable technology, this study addresses the limitations of traditional rehabilitation assessments in capturing real-world experiences and dynamic variations. Specifically, it focuses on continuously monitoring physical activity in hip and knee OA patients using automated unsupervised evaluations within the rehabilitation process. We analyzed data from 1144 patients who used a mobile health application after surgery; the activity data were collected using the Garmin Vivofit 4. Several parameters, such as the total number of steps per day, the peak 6-minute consecutive cadence (P6MC) and peak 1-minute cadence (P1M), were computed and analyzed on a daily basis. The results indicated that cadence-based measurements can effectively, and earlier, differ among patients with hip and knee conditions, as well as in the recovery process. Comparisons based on recovery status and type of surgery reveal distinctive trajectories, emphasizing the effectiveness of P6MC and P1M in detecting variations earlier than total steps per day. Furthermore, cadence-based measurements showed a lower inter-day variability (40%) compared to the total number of steps per day (80%). Automated assessments, including P1M and P6MC, offer nuanced insights into the patients' dynamic activity profiles.

Calibration and validation of physical behaviour cut-points using wrist-worn ActiGraphs for children and adolescents: A systematic review

OBJECTIVES

To review cut-points calibrated and independently validated from wrist-worn ActiGraph accelerometers to measure moderate to vigorous physical activity (MVPA) and time spent sedentary (SED) in children and adolescents.

DESIGN

Systematic literature review.

METHODS

Five databases were searched for relevant cut-point calibration and independent validation studies relating to wrist worn ActiGraphs in children and adolescents from inception through 30 April 2022. Extracted data included: country of publication; study name; population; device model; wear location; sampling frequency; epoch length; activity protocol; criterion method and definitions used to classify PA intensity; statistical methods for calibration; statistical methods for validation/cross-validation; and MVPA and SED outcome.

RESULTS

Fourteen calibration studies and seven independent validation studies were identified. Calibrated cut-points for MVPA vector magnitude counts ranged from 7065 to 9204 counts per minute (cpm) and 63.5 to 201 milli-gravitational units (mg). For SED, calibrated cut-points ranged from <2556 cpm to 4350 cpm and 30.8 to 48.1 mg. Classification accuracy values determined by independent validation studies varied, with kappa values ranging from 0.31 to 0.60 and area under the curve statistics ranging from 0.51 to 0.84 for MVPA and kappa values ranging from 0.31 to 0.44 and area under the curve statistics ranging from 0.70 to 0.85 for SED.

CONCLUSIONS

The results of this systematic literature review support the use of the Crouter and colleagues cut-points for the measurement of MVPA and SED for children and adolescents aged 6-12 years. Further work is required to independently validate cut-points developed in younger children and older adolescents.

Early post-operative walking bouts are associated with improved gait speed and symmetry at 90 days

INTRODUCTION

There is a paucity of literature on optimal patterns of daily walking following joint arthroplasty, which are now evaluated with consumer technologies like smartphones, and can enhance our understanding of post-operative mobility. When smartphone-recorded, daily walking patterns are captured, qualities of gait-recovery such as gait speed or symmetry can be analyzed in real-world environments.

RESEARCH QUESTION

Are the daily distribution of walking bouts in the early post-operative period associated with 90-day gait quality measures following hip and knee arthroplasty?

METHODS

Gait data was collected passively using a smartphone-based care management platform in patients undergoing hip and knee arthroplasty. As recorded via subjects' free-living smartphone-collected gait bouts, data were investigated as a function of the walking session length and were used to create a ratio to the total time logging bouts, representing the fraction of walking performed during a single session per day (aggregation score). Quantile regression was performed to evaluate the association between early walking session lengths or aggregation score at 30 days post-operatively and the gait-sampled speed and asymmetry of walking at 90 days.

RESULTS

In total, 2255 patients provided evaluable data. The walking session length at 30 days was positively associated with 90-day mean gait speed across procedure types where quantile regression coefficients ranged from 0.11 to 0.17. In contrast, aggregation score was negatively associated with gait speed at 90 days, with coefficients ranging from -0.18 to -0.12.

SIGNIFICANCE

The duration and frequency of walking bouts was associated with recovery of gait speed and symmetry following lower limb arthroplasty. The findings may help clinicians design walking protocols that are associated with improved gait metrics at 3 months.

Supervised Learning of Physical Activity Features From Functional Accelerometer Data

OBJECTIVE

We propose a new health informatics framework to analyze physical activity (PA) from accelerometer devices. Accelerometry data enables scientists to extract personal digital features useful for precision health decision making. Existing methods in accelerometry data analysis typically begin with discretizing summary counts by certain fixed cutoffs into activity categories. One well-known limitation is that the chosen cutoffs are often validated under restricted settings, and cannot be generalizable across populations, devices, or studies.

METHODS

We develop a data-driven approach to overcome this bottleneck in PA data analysis, in which we holistically summarize a subject's activity profile using Occupation-Time curves (OTCs), which describe the percentage of time spent at or above a continuum of activity count levels. We develop multi-step adaptive learning algorithms to perform supervised learning via a scalar-on-function model that involves OTC as the functional predictor of interest as well as other scalar covariates. Our learning analytic first incorporates a hybrid approach of fused lasso for clustering and Hidden Markov Model for changepoint detection, then executes refinement procedures to determine activity windows of interest.

RESULTS

We evaluate and illustrate the performance of the proposed learning analytic through simulation experiments and real-world data analyses to assess the influence of PA on biological aging. Our findings indicate a different directional relationship between biological age and PA depending on the specific outcome of interest.

SIGNIFICANCE

Our bioinformatics methodology involves the biomedical outcome of interest to detect different critical points, and is thus adaptive to the specific data, study population, and health outcome under investigation.

Dose-response associations of Monitor-Independent Movement Summary with health-related fitness in youth

The purpose of this study was to determine the dose-response associations between Monitor-Independent Movement Summary (MIMS) units and health-related fitness in youth. The sample comprised US children and adolescents who participated in the 2012 National Youth Fitness Survey (NNYFS; N = 1158, 48.9% female). Health-related fitness domains were assessed using tests of cardiorespiratory endurance (timed maximal and graded treadmill tests), muscular strength (modified pull-up and grip tests), and muscular endurance (plank test). Movement data were collected using wrist-worn ActiGraph accelerometers with raw data processed using MIMS and the calculated metrics of average MIMS/day, Peak 60-min MIMS, and Peak 30-min MIMS. Weighted regression models examined linear associations between MIMS metrics and fitness test scores. Nonlinear associations were examined using weighted spline models with knots placed at the 10th, 50th, and 90th percentiles. Models were adjusted for covariates and fit was examined using the coefficient of determination (R2 ). The strongest adjusted linear relationships included a positive association between MIMS/day (per every 1000 units) and maximal endurance times (b = 5.5 s, p < 0.001) and between Peak 60-min MIMS (per every 10 units) and estimated aerobic capacity (b = 1.7 mL/kg/min, p < 0.001), modified pull-ups (b = 0.7 reps, p < 0.001), and plank test scores (b = 5.0 s, p < 0.001). Linear spline models had slightly higher R2 values (R2 range = 16.9%-74.8%) compared to linear models (R2 range = 15.0%-74.5%). The relationship between MIMS metrics and fitness test scores was best modeled as piecewise linear functions. Although all MIMS metrics associated with cardiorespiratory endurance, Peak 60-min MIMS showed stronger associations with tests of muscular strength and endurance.

Measurement properties of device-based physical activity instruments in ambulatory adults with physical disabilities and/or chronic diseases: a scoping review

BACKGROUND

People with physical disabilities and/or chronic diseases tend to have an inactive lifestyle. Monitoring physical activity levels is important to provide insight on how much and what types of activities people with physical disabilities and/or chronic diseases engage in. This information can be used as input for interventions to promote a physically active lifestyle. Therefore, valid and reliable physical activity measurement instruments are needed. This scoping review aims 1) to provide a critical mapping of the existing literature and 2) directions for future research on measurement properties of device-based instruments assessing physical activity behavior in ambulant adults with physical disabilities and/or chronic diseases.

METHODS

Four databases (MEDLINE, CINAHL, Web of Science, Embase) were systematically searched from 2015 to April 16th 2023 for articles investigating measurement properties of device-based instruments assessing physical activity in ambulatory adults with physical disabilities and/or chronic diseases. For the majority, screening and selection of eligible studies were done in duplicate. Extracted data were publication data, study data, study population, device, studied measurement properties and study outcome. Data were synthesized per device.

RESULTS

One hundred three of 21566 Studies were included. 55 Consumer-grade and 23 research-grade devices were studied on measurement properties, using 14 different physical activity outcomes, in 23 different physical disabilities and/or chronic diseases. ActiGraph (n = 28) and Fitbit (n = 39) devices were most frequently studied. Steps (n = 68) was the most common used physical activity outcome. 97 studies determined validity, 11 studies reliability and 6 studies responsiveness.

CONCLUSION

This scoping review shows a large variability in research on measurement properties of device-based instruments in ambulatory adults with physical disabilities and/or chronic diseases. The variability highlights a need for standardization of and consensus on research in this field. The review provides directions for future research.

Association between circadian physical activity patterns and mortality in the UK Biobank

BACKGROUND

The benefit of physical activity (PA) for increasing longevity is well-established, however, the impact of diurnal timing of PA on mortality remains poorly understood. We aimed to derive circadian PA patterns and investigate their associations with all-cause mortality.

METHODS

We used 24 h PA time series from 96,351 UK Biobank participants aged between 42 and 79 years at accelerometry in 2013-2015. Functional principal component analysis (fPCA) was applied to obtain circadian PA patterns. Using multivariable Cox proportional hazard models, we related the loading scores of these fPCs to estimate risk of mortality.

RESULTS

During 6.9 years of follow-up, 2,850 deaths occurred. Four distinct fPCs accounted for 96% of the variation of the accelerometry data. Using a loading score of zero (i.e., average overall PA during the day) as the reference, a fPC1 score of + 2 (high overall PA) was inversely associated with mortality (Hazard ratio, HR = 0.91; 95% CI: 0.84-0.99), whereas a score of -2 (low overall PA) was associated with higher mortality (1.69; 95% CI: 1.57-1.81; p for non-linearity < 0.001). Significant inverse linear associations with mortality were observed for engaging in midday PA instead of early and late PA (fPC3) (HR for a 1-unit increase 0.88; 95% CI: 0.83-0.93). In contrast, midday and nocturnal PA instead of early and evening PA (fPC4) were positively associated with mortality (HR for a 1-unit increase 1.16; 95% CI: 1.08-1.25).

CONCLUSION

Our results suggest that it is less important during which daytime hours one is active but rather, to engage in some level of elevated PA for longevity.

Validity of Apple Watch 6 and Polar A370 for monitoring energy expenditure while resting or performing light to vigorous physical activity

OBJECTIVES

The purpose of this study was to assess the validity of energy expenditure measurements taken by the Apple Watch 6 and Polar A370 during resting, light- to vigorous-intensity running on the treadmill and ground, and post-exercise of each speed.

DESIGN

Randomized cross-over trial.

METHODS

This study included 11 male adults (22.5 ± 1.8 years old). Participants were asked to wear the Apple Watch 6 and the Polar A370 simultaneously to measure energy expenditure under various intensities of physical activities on the treadmill and ground, which were then compared with results from a gas metabolism analysis system.

RESULTS

Monitoring energy expenditure for both treadmill and ground, the Apple Watch 6 (range: 13.40-50.34 %) had a higher mean absolute percent error than the Polar A370 (range: 12.74-27.70 %) in resting and running state, while the mean absolute percent error of the Apple Watch 6 (range: 9.71-32.81 %) is smaller than that of the Polar A370 (15.79-43.51 %) in post-exercise. The Apple Watch 6 tends to overestimate energy expenditure, with a mean percent error ranging from -6.61 % to 53.24 %, while the Polar A370 tends to underestimate energy expenditure, with a mean percent error ranging from -3.51 % to 11.33 %. No estimated energy expenditure of both devices fell in the equivalence testing zone.

CONCLUSIONS

For young adult males, the Apple Watch 6 and Polar A370 provide similar levels of accuracy in monitoring energy expenditure during treadmill and ground running exercise. However, both devices are still inadequate in this regard.

Development of an Online Mind-Body Physical Activity Intervention for Young Adults during COVID-19: A Pilot Study

The purpose of this study was to examine the association between the implementation of an online mind-body physical activity (MBPA) intervention and physical activity (PA), stress, and well-being in young adults during COVID-19. The participants were a sample of college students (N = 21; 81% female). The MBPA intervention was organized in four online modules that were administered asynchronously for 8 weeks with three separate 10 min sessions per week. The intervention components consisted of traditional deep breathing, diaphragm mindful breathing, yoga poses, and walking meditation. Objective PA behaviors were assessed using wrist-worn ActiGraph accelerometers, and stress and well-being data were collected using validated self-report instruments. A 2 (sex) × 3 (time) doubly multivariate analysis of variance test with a univariate follow-up showed that the % of wear time in light (LPA) and moderate-to-vigorous physical activity (MVPA) was significantly higher at the end of the intervention compared to baseline (LPA mean difference = 11.3%, p = 0.003, d = 0.70; MVPA mean difference = 2.9%, p < 0.001, d = 0.56). No significant differences were observed for perceived stress and well-being, and there was no moderating effect of sex. The MBPA intervention showed promise, as it was associated with higher PA in young adults during COVID-19. No improvements were observed for stress and well-being. These results warrant further testing of the intervention's effectiveness using larger samples.

Historical development of accelerometry measures and methods for physical activity and sedentary behavior research worldwide: A scoping review of observational studies of adults

This scoping review identified observational studies of adults that utilized accelerometry to assess physical activity and sedentary behavior. Key elements on accelerometry data collection were abstracted to describe current practices and completeness of reporting. We searched three databases (PubMed, Web of Science, and SPORTDiscus) on June 1, 2021 for articles published up to that date. We included studies of non-institutionalized adults with an analytic sample size of at least 500. The search returned 5686 unique records. After reviewing 1027 full-text publications, we identified and abstracted accelerometry characteristics on 155 unique observational studies (154 cross-sectional/cohort studies and 1 case control study). The countries with the highest number of studies included the United States, the United Kingdom, and Japan. Fewer studies were identified from the continent of Africa. Five of these studies were distributed donor studies, where participants connected their devices to an application and voluntarily shared data with researchers. Data collection occurred between 1999 to 2019. Most studies used one accelerometer (94.2%), but 8 studies (5.2%) used 2 accelerometers and 1 study (0.6%) used 4 accelerometers. Accelerometers were more commonly worn on the hip (48.4%) as compared to the wrist (22.3%), thigh (5.4%), other locations (14.9%), or not reported (9.0%). Overall, 12.7% of the accelerometers collected raw accelerations and 44.6% were worn for 24 hours/day throughout the collection period. The review identified 155 observational studies of adults that collected accelerometry, utilizing a wide range of accelerometer data processing methods. Researchers inconsistently reported key aspects of the process from collection to analysis, which needs addressing to support accurate comparisons across studies.

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.

Investigating Wrist-Based Acceleration Summary Measures across Different Sample Rates towards 24-Hour Physical Activity and Sleep Profile Assessment

Wrist-worn wearable sensors have attracted considerable research interest because of their potential in providing continuous, longitudinal, non-invasive measurements, leading to insights into Physical Activity (PA), sleep, and circadian variability. Three key practical considerations for research-grade wearables are as follows: (a) choosing an appropriate sample rate, (b) summarizing raw three-dimensional accelerometry data for further processing (accelerometry summary measures), and (c) accurately estimating PA levels and sleep towards understanding participants' 24-hour profiles. We used the CAPTURE-24 dataset, where 148 participants concurrently wore a wrist-worn three-dimensional accelerometer and a wearable camera over approximately 24 h to obtain minute-by-minute labels: sleep; and sedentary light, moderate, and vigorous PA. We propose a new acceleration summary measure, the Rate of Change Acceleration Movement (ROCAM), and compare its performance against three established approaches summarizing three-dimensional acceleration data towards replicating the minute-by-minute labels. Moreover, we compare findings where the acceleration data was sampled at 10, 25, 50, and 100 Hz. We demonstrate the competitive advantage of ROCAM towards estimating the five labels (80.2% accuracy) and building 24-hour profiles where the sample rate of 10 Hz is fully sufficient. Collectively, these findings provide insights facilitating the deployment of large-scale longitudinal actigraphy data processing towards 24-hour PA and sleep-profile assessment.

Evaluating Outdoor Nature-Based Early Learning and Childcare Provision for Children Aged 3 Years: Protocol of a Feasibility and Pilot Quasi-Experimental Design

Systematic reviews have demonstrated the scarcity of well-designed evaluations investigating outdoor nature-based play and learning provision for children in the early learning and childcare (ELC) sector among global Western countries. This study will examine the feasibility and acceptability of the programme and the evaluation design of outdoor nature-based play and learning provision across urban ELC settings in a Scottish metropolitan city. Six ELC settings with different outdoor nature-based play delivery models will be recruited. One trial design will be tested: a quasi-experimental comparison of children attending three different models of outdoor play and learning provision. Measures will be assessed at baseline and five weeks later. Key feasibility questions include: recruitment and retention of ELC settings and children; suitability of statistical matching based on propensity score; completeness of outcome measures. Process evaluation will assess the acceptability of trial design methods and provision of outdoor nature-based play among ELC educators. These questions will be assessed against pre-defined progression criteria. This feasibility study will inform a powered effectiveness evaluation and support policy making and service delivery in the Scottish ELC sector.