Effects of eHealth Interventions on 24-Hour Movement Behaviors Among Preschoolers: Systematic Review and Meta-Analysis.

BACKGROUND: The high prevalence of unhealthy movement behaviors among young children remains a global public health issue. eHealth is considered a cost-effective approach that holds great promise for enhancing health and related behaviors. However, previous research on eHealth interventions aimed at promoting behavior change has primarily focused on adolescents and adults, leaving a limited body of evidence specifically pertaining to preschoolers. OBJECTIVE: This review aims to examine the effectiveness of eHealth interventions in promoting 24-hour movement behaviors, specifically focusing on improving physical activity (PA) and sleep duration and reducing sedentary behavior among preschoolers. In addition, we assessed the moderating effects of various study characteristics on intervention effectiveness. METHODS: We searched 6 electronic databases (PubMed, Ovid, SPORTDiscus, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials) for experimental studies with a randomization procedure that examined the effectiveness of eHealth interventions on 24-hour movement behaviors among preschoolers aged 2 to 6 years in February 2023. The study outcomes included PA, sleep duration, and sedentary time. A meta-analysis was conducted to assess the pooled effect using a random-effects model, and subgroup analyses were conducted to explore the potential effects of moderating factors such as intervention duration, intervention type, and risk of bias (ROB). The included studies underwent a rigorous ROB assessment using the Cochrane ROB tool. Moreover, the certainty of evidence was evaluated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) assessment. RESULTS: Of the 7191 identified records, 19 (0.26%) were included in the systematic review. The meta-analysis comprised a sample of 2971 preschoolers, which was derived from 13 included studies. Compared with the control group, eHealth interventions significantly increased moderate to vigorous PA (Hedges g=0.16, 95% CI 0.03-0.30; P=.02) and total PA (Hedges g=0.37, 95% CI 0.02-0.72; P=.04). In addition, eHealth interventions significantly reduced sedentary time (Hedges g=-0.15, 95% CI -0.27 to -0.02; P=.02) and increased sleep duration (Hedges g=0.47, 95% CI 0.18-0.75; P=.002) immediately after the intervention. However, no significant moderating effects were observed for any of the variables assessed (P>.05). The quality of evidence was rated as "moderate" for moderate to vigorous intensity PA and sedentary time outcomes and "low" for sleep outcomes. CONCLUSIONS: eHealth interventions may be a promising strategy to increase PA, improve sleep, and reduce sedentary time among preschoolers. To effectively promote healthy behaviors in early childhood, it is imperative for future studies to prioritize the development of rigorous comparative trials with larger sample sizes. In addition, researchers should thoroughly examine the effects of potential moderators. There is also a pressing need to comprehensively explore the long-term effects resulting from these interventions. TRIAL REGISTRATION: PROSPERO CRD42022365003; http://tinyurl.com/3nnfdwh3.

Barriers and facilitators to physical activity for young adult women: a systematic review and thematic synthesis of qualitative literature.

BACKGROUND: Physical activity (PA) has many benefits in preventing diseases and maintaining physical and mental health. Women, in particular, can benefit from regular PA. However, women's PA did not increase over the past decade globally, and the situations faced by women are often gender-specific. Healthy young adult women's PA does not receive as much attention as older women and adolescent girls, yet, they face the same situation of low level of PA. This review aims to explore and synthesise the self-identified barriers and facilitators to young adult women's participation in PA from qualitative research studies and offer suggestions for future studies and programs designed for this population. METHODS: A systematic search was conducted in Pubmed, Web of Science, Scopus, Medline, and SPORTDiscus for studies published between January 2000 to February 2022 to identify qualitative studies on the barriers and facilitators of young adult women's PA between ages 18 to 40. The search yielded 694 studies initially, of which 23 were included. The research quality of included studies was appraised using the Critical Appraisal Skills Programme (CASP) tool. Data were extracted and thematically analysed based on the tenets of the social-ecological model (SEM). RESULTS: Identified barriers and facilitators were grouped into different levels of the SEM, with the most frequently cited factors being time, body image and societal beauty standards, family duty and social support, religious and cultural norms, organisation and community facilities and environment, safety issues and physical environment. Descriptive data were thematically analysed and synthesised in line with the five levels: body image, health and beauty; multiple roles, support, and PA; religious identity, cultural identity, and PA; safety issues and women's fears. CONCLUSIONS: This qualitative synthesis revealed in-depth information on barriers and facilitators influencing young adult women's PA. It highlighted that the factors young adult women face are diverse at different levels yet holistic and intertwined. Future studies on young adult women's PA should address the social-cultural influence and would benefit from applying multilevel strategies employing the SEM model. It is critical to create an open and inclusive environment and offer more opportunities for women. TRIAL REGISTRATION: PROSPERO CRD42021290519.

Parent-focused online intervention to promote parents' physical literacy and support children's physical activity: results from a quasi-experimental trial.

BACKGROUND: The development of physical literacy (PL) early in life may influence children's subsequent physical activity (PA) participation and consequent health benefits across the life course. Interventions designed for parents are lacking, but such efforts can potentially enhance the PL of parents and their children's PA participation. Additionally, there is insufficient evidence to support the feasibility of delivering a PL intervention using an online format. Therefore, the purpose of this study was to examine the feasibility and effectiveness of a parent-focused, theory-driven, online-delivered intervention designed to improve the parents' PL and children's PA behaviors. METHODS: A non-randomized trial was conducted to evaluate the effects of the program. 224 Hong Kong families (primary school-aged children and their parents) registered to the program were considered the experimental group and were exposed to an online intervention over three months. Another 220 families in Hong Kong were considered the comparison group and did not receive any intervention. Outcome measures included PA behaviors (daily steps and moderate-to-vigorous PA), parent-child co-activity behaviors, family PA routines, and parent perceived PL. Linear mixed models were used to analyze the differences in terms of changes in measured outcomes between groups over time. RESULTS: No significant group-by-time effects were found for children's or parents' PA behaviors. In terms of the family Co-PA routines, a small positive effect size in favor of the experimental group was found (p = .44, d = 0.2). Group-by-time effects favorable to the experimental group was detected for parent-child co-activity (p < .001, d = 0.7) and parental PL (p < .001, d = 0.9) at post-intervention. The results demonstrated that the intervention was acceptable and that there was potential for scale up. CONCLUSIONS: Findings indicated that the intervention was effective in increasing parent-child co-activity and parent perceived PL. During the pandemic, online intervention delivery was found to be feasible. Using this mode of delivery, the intervention has the potential to reach a wide population in the local context. TRIAL REGISTRATION: The study was prospectively registered at the Chinese Clinical Trial Registry, Registration number: ChiCTR2100041903, Registered 09 January 2021.

Parental Support, Children's Physical Activity, Dietary Behaviors and Health-Related Quality of Life: Evidence From Three Asian Cities.

BACKGROUND: Parental support is crucial for children's healthy lifestyle formation. The present study examined the relations between parental support (i.e., encouragement and praise), children's perceived autonomy support and behaviors in the domains of physical activity (PA) and diet, and health-related quality of life (HRQoL) simultaneously in Asia. METHOD: Children aged 9 to 12 years and their parents (2065 dyads) in three Asian cities completed the respective questionnaires. Children reported perceived PA and dietary autonomy support, PA frequency, dietary behaviors, and HRQoL. Parents reported their PA and dietary support. The relations between parental support, children's perceived autonomy support an behaviors in the PA, and dietary domains as well as HRQoL were examined using multigroup path analyses. RESULTS: Among three cities, the indirect effects of parental support on children's self-report PA or HRQoL via children's perceived PA autonomy support were significant. A hypothetical sequential indirect effect from parental PA support to children's HRQoL via children's perceived PA autonomy support and self-report PA was observed in Hong Kong. In Hong Kong and Taipei samples, the indirect effect of parental PA support on children's HRQoL via children's self-report PA and the indirect effect of children's perceived PA autonomy support on HRQoL via children's self-report PA were significant. In Hong Kong and Shanghai samples, children's perceived dietary autonomy support showed positive effect on HRQoL via healthy food consumption. CONCLUSIONS: Congruent findings across three cities suggest that parents should provide support via encouragement and praise to facilitate children's perceived autonomy support and further increase PA and HRQoL. Our study adds to the literature by examining relations of parental support and children's healthy lifestyle in Asia and provides insights to parents and researchers.

Effect of family income and physical activity on children's quality of life.

It is unclear whether gender differences exist in the relationship between maternal physical activity (PA) and children's quality of life (QoL). We also know relatively little about the potential role of PA in mitigating the adverse impact of family financial hardship. This study examined the interaction effect of PA with social and demographic factors on QoL among 272 primary school children and their mothers in Hong Kong. Children self-reported their QoL, whereas mothers reported their own and children's PA levels. Mothers also reported their family demographics including monthly household income. Moderated multiple regression models were calculated to examine 1) the relationship between maternal PA and child QoL based on child gender and 2) the relationship between family income status and child QoL based on maternal-child PA level status. The relationship between maternal PA and child QoL varied by child gender (ß = .21, p = .049), with boys of active mothers showing higher QoL. Compared to active families, when both mothers and boys were inactive, there were bigger income differences in child QoL scores (ß = .37, p = .041). No significant differences were observed in girls. The findings have implications for family-based PA interventions and highlights the benefits of PA toward the QoL of male children in disadvantaged families.

Improving children's fundamental movement skills through a family-based physical activity program: results from the "Active 1 + FUN" randomized controlled trial.

BACKGROUND: Physical activity is related to many positive health outcomes, yet activity levels of many children are low. Researchers have suggested that family-based interventions may improve physical activity behaviors of both children and their parents. In this study, we evaluated the "Active 1 + FUN" program, which was designed based on tenets of self-determination theory. Intervention components included free sporting equipment, ten coach-led workshops and activity sessions, and one booster session. METHODS: We evaluated the intervention program using a randomized controlled trial. One hundred seventy-one families were randomly allocated to either an experimental group or a wait-list control group. Participants were exposed to program contents over a nine-month period, while families in the control did not receive any form of intervention. Measured constructs included moderate-to-vigorous physical activity, co-physical activity behaviors, fundamental movement skills, BMI, and several self-reported questionnaire outcomes. Hierarchical linear modeling was used to compare changes in measured outcomes across the two groups. RESULTS: No significant intervention effects were found for children's and parents' accelerometer-measured moderate-to-vigorous physical activity, or their co-physical activity. However, in terms of children's fundamental movement skills, a significant Time*Group interaction (B = 0.52, 95% CI [0.07, 0.96] for Times 1 to 2; B = 0.24, 95% CI [0.01, 0.48] for Times 1 to 3) in favor of the experimental group was found. CONCLUSIONS: Results suggested that the "Active 1 + FUN" program was effective in improving children's fundamental movement skills. Additional research is needed to examine how family-based initiatives could effectively improve physical activity behaviors too. TRIAL REGISTRATION: ANZCTR, ACTRN12618001524280. Registered 11 September 2018, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375660 .

Global effect of COVID-19 pandemic on physical activity, sedentary behaviour and sleep among 3- to 5-year-old children: a longitudinal study of 14 countries.

BACKGROUND: The restrictions associated with the 2020 COVID-19 pandemic has resulted in changes to young children's daily routines and habits. The impact on their participation in movement behaviours (physical activity, sedentary screen time and sleep) is unknown. This international longitudinal study compared young children's movement behaviours before and during the COVID-19 pandemic. METHODS: Parents of children aged 3-5 years, from 14 countries (8 low- and middle-income countries, LMICs) completed surveys to assess changes in movement behaviours and how these changes were associated with the COVID-19 pandemic. Surveys were completed in the 12 months up to March 2020 and again between May and June 2020 (at the height of restrictions). Physical activity (PA), sedentary screen time (SST) and sleep were assessed via parent survey. At Time 2, COVID-19 factors including level of restriction, environmental conditions, and parental stress were measured. Compliance with the World Health Organizations (WHO) Global guidelines for PA (180 min/day [≥60 min moderate- vigorous PA]), SST (≤1 h/day) and sleep (10-13 h/day) for children under 5 years of age, was determined. RESULTS: Nine hundred- forty-eight parents completed the survey at both time points. Children from LMICs were more likely to meet the PA (Adjusted Odds Ratio [AdjOR] = 2.0, 95%Confidence Interval [CI] 1.0,3.8) and SST (AdjOR = 2.2, 95%CI 1.2,3.9) guidelines than their high-income country (HIC) counterparts. Children who could go outside during COVID-19 were more likely to meet all WHO Global guidelines (AdjOR = 3.3, 95%CI 1.1,9.8) than those who were not. Children of parents with higher compared to lower stress were less likely to meet all three guidelines (AdjOR = 0.5, 95%CI 0.3,0.9). CONCLUSION: PA and SST levels of children from LMICs have been less impacted by COVID-19 than in HICs. Ensuring children can access an outdoor space, and supporting parents' mental health are important prerequisites for enabling pre-schoolers to practice healthy movement behaviours and meet the Global guidelines.

Promoting physical activity in children through family-based intervention: protocol of the "Active 1 + FUN" randomized controlled trial.

BACKGROUND: Physical activity (PA) is beneficial to people's physical and psychological health. Physically active children are likely to become active adults; thus, active lifestyles should be promoted from childhood. Parents are crucial for shaping their children's behaviors, but many lack the knowledge and skills to provide optimal support for PA. The "Active 1 + FUN" intervention was designed to enhance PA of the whole family, and improve parenting methods of both fathers and mothers. METHODS: "Active 1 + FUN" is a family-based intervention designed using the tenets of self-determination theory. The intervention was designed to help parents support their children's basic psychological needs for competence (by providing informational feedback and optimal challenges), autonomy (by exploring a variety of activities and reducing controlling behaviors), and relatedness (by increasing co-PA between parents and child). The intervention components include interactive workshops, activity sessions, physical activity homework, activity planning consultations, easy sports equipment, and online materials. A randomized controlled trial will be conducted to evaluate the intervention. A target sample of 204 Primary three to five students (8 to 11 years) and their parents will be randomly allocated to the experimental group or a wait-list control group. The experimental group will receive a ten-session intervention which spans approximately six months. The control group will receive intervention one year later. Children's accelerometer-based leisure-time physical activity (primary outcome) and secondary outcomes will be assessed at baseline, at end of intervention period (6 months after baseline), and at follow-up (12 months after baseline). Qualitative interviews will be conducted to determine effective intervention components from the perspective of children and parents. We hypothesize that the intervention will increase parents' and children's activity behaviors and that children will experience higher levels of needs satisfaction with regard to physical activity participation. DISCUSSION: Physical activity interventions often target children only, but ones that also involve parents may be more beneficial. The "Active 1 + FUN" intervention will be organized and delivered by trained trainers. Consequently, this intervention could be scaled to a larger number of Hong Kong schools in the future and could impact a wider population of schoolchildren. TRIAL REGISTRATION: ANZCTR ACTRN12618001524280 . Registered 11 September 2018.

Associations between fundamental movement skill competence, physical activity and psycho-social determinants in Hong Kong Chinese children.

Associations between fundamental movement skills (FMS), perceived competence, enjoyment and physical activity (PA) have not been widely investigated among Chinese school children. We hypothesised that FMS would be directly related to self-reported and objectively measured PA, and indirectly related to these outcomes via perceived physical and movement skill competence, and enjoyment. Participants were 763 primary school children (age = 9.3 ± 1.7 years; 474 girls) across grades. FMS were measured for a subsample (n = 603) using Test of Gross Motor Development-2. PA using accelerometers was obtained from this subgroup (n = 238). All participating children completed a questionnaire measuring their PA participation, enjoyment, and perceived physical and movement skill competence. Structural equation modelling revealed positive associations between locomotor skills and perceived movement skill competence (ß = .11, 95% CI [.001, .22]), and between perceived movement skill competence and objectively measured PA (ß = .59, 95% CI [.04, 1.14]). Perceived physical competence and enjoyment mediated the association between locomotor skills and self-reported PA (ß = .08, 95% CI [.02, .12]), but not objectively measured PA. Given inconsistent findings for subjective and objective measures of PA, further mediation analyses of the association between FMS and PA may be warranted.

A school-based rope skipping program for adolescents: Results of a randomized trial.

Despite physical education's health enhancing potential, students' activity levels in lessons are low. We evaluated a school-based intervention that involved rope skipping on students' moderate-to-vigorous physical activity (MVPA) in physical education. The intervention was evaluated using a clustered randomized controlled trial in 24 classes (N=731 students; M=14.38years; all from Secondary 2) from 12 Hong Kong schools during September to December 2013. The primary outcome was percentage of lesson time spent in MVPA. Secondary outcomes included students' vigorous activity, counts per minute, perceived autonomy support and motivation for physical education. Accelerometer-based activity measures were taken from a sub-sample of 168 students during lessons 1 to 3 (baseline) and lessons 5 to 7 (treatment phase). Participants self-reported motivation variables at lessons 4 and 8. Teachers allocated to the experimental group included an intervention during treatment phase; those in the control group continued usual practices. The intervention involved a 15-minute rope skipping activity where students completed intervals of skipping with rests in between. Using multilevel modeling, we examined the intervention effects on measured outcomes, and whether effects differed for boys and girls. Overall intervention effects were not found. However, girls in the intervention group spent more time in MVPA (ß=0.25) and had higher counts per minute (ß=0.32) than control group counterparts at treatment phase. Perceived autonomy support and motivation variables were similar across groups. The intervention increased activity levels of girls, but not boys. Implementation of the intervention may reduce differences between boys' and girls' physical education activity levels. TRIAL REGISTRATION: ANZCTR: ACTRN12613000968774.

Increasing students' physical activity during school physical education: rationale and protocol for the SELF-FIT cluster randomized controlled trial.

BACKGROUND: The Self-determined Exercise and Learning For FITness (SELF-FIT) is a multi-component school-based intervention based on tenets of self-determination theory. SELF-FIT aims to increase students' moderate-to-vigorous physical activity (MVPA) during physical education lessons, and enhance their autonomous motivation towards fitness activities. Using a cluster randomized controlled trial, we aim to examine the effects of the intervention on students' MVPA during school physical education. METHODS: Secondary 2 students (approximately aged 14 years) from 26 classes in 26 different schools will be recruited. After baseline assessments, students will be randomized into either the experimental group or wait-list control group using a matched-pair randomization. Teachers allocated to the experimental group will attend two half-day workshops and deliver the SELF-FIT intervention for 8 weeks. The main intervention components include training teachers to teach in more need supportive ways, and conducting fitness exercises using a fitness dice with interchangeable faces. Other motivational components, such as playing music during classes, are also included. The primary outcome of the trial is students' MVPA during PE lessons. Secondary outcomes include students' leisure-time MVPA, perceived need support from teachers, need satisfaction, autonomous motivation towards physical education, intention to engage in physical activity, psychological well-being, and health-related fitness (cardiorespiratory and muscular fitness). Quantitative data will be analyzed using multilevel modeling approaches. Focus group interviews will also be conducted to assess students' perceptions of the intervention. DISCUSSION: The SELF-FIT intervention has been designed to improve students' health and well-being by using high-intensity activities in classes delivered by teachers who have been trained to be autonomy needs supportive. If successful, scalable interventions based on SELF-FIT could be applied in physical education at large. TRIAL REGISTRATION: The trial is registered at the Australia New Zealand Clinical Trial Registry (Trial ID: ACTRN12615000633583 ; date of registration: 18 June 2015).

Effects of Fundamental Movement Skills Training on Children With Developmental Coordination Disorder.

The purpose of this study was to examine the effects of fundamental movement skills (FMS) training on FMS proficiency, self-perceived physical competence (SPC), physical activity (PA), and sleep disturbance in children with developmental coordination disorder (DCD) compared with children with typical development (TD). A total of 84 children were allocated into either experimental group (DCD[exp], TD[exp]) who received 6 weeks of FMS training or control groups (DCD[con], TD[con]). FMS were assessed using the Test of Gross Motor Development-2, whereas PA was monitored using accelerometers. SPC and sleep disturbance were evaluated using questionnaires. Results showed that the DCD[exp] group had significantly higher scores in FMS and SPC compared with the DCD[con] group at posttest. The DCD[exp] group scored lower in sleep disturbance at follow-up when compared with posttest. It is suggested that short-term FMS training is effective in improving FMS and SPC and reducing sleep disturbances for children with DCD.

Psychometric properties of the Chinese (Cantonese) versions of the KIDSCREEN health-related quality of life questionnaire.

PURPOSE: The KIDSCREEN questionnaire assesses health-related quality of life in children and adolescents. In this study, the questionnaire was translated into Chinese (Cantonese) and administered to two independent groups of Hong Kong Chinese students. Various aspects of reliability and validity of the KIDSCREEN-52 and KIDSCREEN-27 questionnaires were examined. METHODS: The translated KIDSCREEN-52 questionnaire (and thus the KIDSCREEN-27 as a subset of the long form) was administered to cohorts of 1379 and 555 students. Confirmatory factor analysis and partial credit Rasch analyses were used to examine the underlying structure of the instrument. Test-retest reliability, convergent, and divergent validity were also examined. RESULTS: The 10-factor structure of the Chinese KIDSCREEN-52 was supported. However, the original five-factor model of the KIDSCREEN-27 was not supported as seven distinct factors were found. Internal consistency and test-retest reliability were acceptable. Evidence supporting convergent and divergent validity was found. CONCLUSIONS: Results from the two studies supported the use of the translated Chinese version of KIDSCREEN questionnaire children and adolescents' health-related quality of life. Further research is required to examine possible cultural or language differences between the original version and the translated Chinese version of the questionnaire.

A school-based rope skipping intervention for adolescents in Hong Kong: protocol of a matched-pair cluster randomized controlled trial.

BACKGROUND: Schools present venues for physical activity promotion among youth, with physical education (PE) considered the primary vehicle responsible for increasing activity levels. Yet students are not very physically active during typical school PE classes. With the aim to engage Hong Kong students in more moderate-to-vigorous physical activity (MVPA) during PE, a fitness infusion intervention using rope skipping was designed, and its effectiveness will be examined. Rope skipping was chosen because a) it provides moderate-to-high intensity physical activity; b) is inexpensive; c) students find it enjoyable; and d) is feasible in typical environments in Hong Kong, where PE classes are large in size (up to 40 students) and space available for physical activity is usually limited. METHODS/DESIGN: A matched-pair cluster randomized controlled trial was designed. Secondary school students from 24 classes (from 12 schools) will be recruited to participate in the trial. Students' baseline MVPA will be measured during school PE. Classes will be matched according to baseline variables and one class from each pair will be randomized into the experimental group. Teachers in the experimental group will be invited to attend a teacher workshop, and will insert a 15-minute rope skipping activity in four consecutive PE lessons. Motivational factors based on self-determination theory will also be measured as secondary outcomes. The effectiveness of the intervention will be evaluated by comparing changes in the proportion of lesson time spent in MVPA from baseline to follow-up across the experimental and control groups. DISCUSSION: Physical activity levels in PE are often very low and there is a need to identify feasible low-cost interventions that can be easily disseminated. If the results of the study suggest the intervention to be effective, it could be implemented to schools throughout Hong Kong and other cities where space is limited. TRAIL REGISTRATION ANZCTR: ACTRN12613000968774. Registered on 30 August 2013.

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

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

Development of a multi-wear-site, deep learning-based physical activity intensity classification algorithm using raw acceleration data.

BACKGROUND: Accelerometers are widely adopted in research and consumer devices as a tool to measure physical activity. However, existing algorithms used to estimate activity intensity are wear-site-specific. Non-compliance to wear instructions may lead to misspecifications. In this study, we developed deep neural network models to classify device placement and activity intensity based on raw acceleration data. Performances of these models were evaluated by making comparisons to the ground truth and results derived from existing count-based algorithms. METHODS: 54 participants (26 adults 26.9±8.7 years; 28 children, 12.1±2.3 years) completed a series of activity tasks in a laboratory with accelerometers attached to each of their hip, wrist, and chest. Their metabolic rates at rest and during activity periods were measured using the portable COSMED K5; data were then converted to metabolic equivalents, and used as the ground truth for activity intensity. Deep neutral networks using the Long Short-Term Memory approach were trained and evaluated based on raw acceleration data collected from accelerometers. Models to classify wear-site and activity intensity, respectively, were evaluated. RESULTS: The trained models correctly classified wear-sites and activity intensities over 90% of the time, which outperformed count-based algorithms (wear-site correctly specified: 83% to 85%; wear-site misspecified: 64% to 75%). When additional parameters of age, height and weight of participants were specified, the accuracy of some prediction models surpassed 95%. CONCLUSIONS: Results of the study suggest that accelerometer placement could be determined prospectively, and non-wear-site-specific algorithms had satisfactory accuracies. The performances, in terms of intensity classification, of these models also exceeded typical count-based algorithms. Without being restricted to one specific wear-site, research protocols for accelerometers wear could allow more autonomy to participants, which may in turn improve their acceptance and compliance to wear protocols, and in turn more accurate results.

Pooled Analysis of Physical Activity, Sedentary Behavior, and Sleep Among Children From 33 Countries.

Importance: The prevalence estimates of physical activity, sedentary behavior, and sleep (collectively known as movement behaviors) in 3- and 4-year-old children worldwide remains uncertain. Objective: To report the proportion of 3- and 4-year-old children who met the World Health Organization guidelines for physical activity, sedentary behavior, and sleep across 33 countries. Design, Setting, and Participants: Pooled analysis of data from 14 cross-sectional studies (July 2008 to September 2022) identified through systematic reviews and personal networks. Thirty-three countries of varying income levels across 6 geographical regions. Each study site needed to have at least 40 children aged 3.0 to 4.9 years with valid accelerometry and parent-/caregiver-reported screen time and sleep duration data. Data were analyzed from October 2022 to February 2023. Exposures: Time spent in physical activity was assessed by reanalyzing accelerometry data using a harmonized data-processing protocol. Screen time and sleep duration were proxy reported by parents or caregivers. Main Outcomes and Measures: The proportion of children who met the World Health Organization guidelines for physical activity (≥180 min/d of total physical activity and ≥60 min/d of moderate- to vigorous-intensity physical activity), screen time (≤1 h/d), and sleep duration (10-13 h/d) was estimated across countries and by World Bank income group and geographical region using meta-analysis. Results: Of the 7017 children (mean [SD] age, 4.1 [0.5] years; 3585 [51.1%] boys and 3432 [48.9%] girls) in this pooled analysis, 14.3% (95% CI, 9.7-20.7) met the overall guidelines for physical activity, screen time, and sleep duration. There was no clear pattern according to income group: the proportion meeting the guidelines was 16.6% (95% CI, 10.4-25.3) in low- and lower-middle-income countries, 11.9% (95% CI, 5.9-22.5) in upper-middle-income countries, and 14.4% (95% CI, 9.6-21.1) in high-income countries. The region with the highest proportion meeting the guidelines was Africa (23.9%; 95% CI, 11.6-43.0), while the lowest proportion was in North and South America (7.7%; 95% CI, 3.6-15.8). Conclusions and Relevance: Most 3- and 4-year-old children in this pooled analysis did not meet the current World Health Organization guidelines for physical activity, sedentary behavior, and sleep. Priority must be given to understanding factors that influence these behaviors in this age group and to implementing contextually appropriate programs and policies proven to be effective in promoting healthy levels of movement behaviors.

A Qualitative Exploration of Facilitators and Barriers to Physical Activity Participation among Chinese Retired Adults in Hong Kong.

The purpose of this study was to identify facilitators and barriers associated with physical activity participation among retired Chinese adults in Hong Kong. This study adopts an interview research design in order to generate an in-depth understanding and insights into the participants' thoughts, motivators and experiences of physical activity participation. Independent, semi-structured interviews with 10 retired participants (aged 54-74) were conducted based on an interview protocol with open-ended questions prompting the participants to describe their experiences. Transcribed texts were analysed using thematic analysis, combining both deductive and inductive analysis techniques. Common physical activities reported were walking, stretching exercise and jogging/running. Participants responded that their physical activity level increased since their retirement. We report the interview results according to the themes which emerged from the analysis: (1) physical and mental health, (2) socio-emotional factors, (3) environmental context, (4) family responsibilities. We found that the themes (1), (2) and (3) act either as a facilitator or a barrier for the participants interviewed, while theme (4) family responsibilities act as a barrier. The findings suggested that future physical activity interventions for retired Chinese adults should include more physical activity knowledge, such as the benefits to physical and mental health brought by physical activity and social elements, considering the specific challenges that participants are confronted with (from the family side).

Examining the relationship between children's health-related quality of life and their perception of parental support toward physical activity: A longitudinal study.

This study investigated how health-related quality of life (HRQOL) affected perception of parental support for physical activity (PA) in 529 children from the "Fun to Move@JC Project." They self-reported their HRQOL, PA enjoyment and motivation, barriers to PA, and attachment to parents in the first semester (Time 1) and perceived parental PA support in the second semester (Time 2). Mediation analyses were performed to examine the underlying mechanisms. Greater Time 1 HRQOL scores predicted higher Time 2 perceived parental PA support through PA enjoyment and motivation, barriers to PA, and attachment to parents at Time 1. The specific indirect effect via attachment to parents was particularly strong in girls, whereas the association of PA enjoyment with perceived parental PA support was stronger in boys. Our findings suggest that children with poor HRQOL may not perceive parents to be supportive of their PA. Interventions promoting parental PA support should emphasize PA enjoyment and benefits to attachment security for parents of boys and girls, respectively.

Examining the criterion validity of two scalable, information technology-based systems designed to measure the quantity and quality of movement behaviours of children from Hong Kong primary schools: a cross-sectional validation study.

OBJECTIVES: Research has shown that having adequate quantity and quality of physical activity can contribute to the health and well-being of children. Nonetheless, existing tools to measure these constructs in children have limitations in terms of their objectivity and scalability. In this study, we provide criterion validity evidence of two systems built on commercially available sensors (ie, gyroscopes and infrared cameras), designed to measure children's moderate-to-vigorous physical activity and fundamental movement skill proficiencies. DESIGN: Cross-sectional. SETTING: Primary schools in Hong Kong. PARTICIPANTS: Data from 30 (age=8.55±1.25 years) and 1174 (age=9.15±1.63 years) children were included for the validation of physical activity and fundamental movement skills measures, respectively. Children's outcomes were simultaneously measured using the developed systems and existing, well-established measures (accelerometers and expert ratings). RESULTS: We found a strong correlation between physical activity outcomes measured using our developed system and accelerometers (Pearson r=0.795). Motor skill proficiency scored using our real-time rating system had strong agreement with expert ratings (percentage agreement=84%-94%, kappa=0.661 to 0.859). DISCUSSION: Results of the current study supported the application of the respective systems in physical education and large-scale research studies. Collection of such data at mass levels could help researchers depict the complex relation between children's quantity and quality of physical activity.