Normative values of motor performance and their relationship with BMI status in Hong Kong preschoolers.

This study aimed to establish sex- and age-specific reference values for motor performance (MP) in Hong Kong preschoolers aged 3-5 years old and examine the relationship between MP and BMI status. A cross-sectional study was conducted among 5579 preschoolers in Hong Kong. Three MP tests were administered, and height and weight information were collected. GAMLSS was used to compute the normative values of the motor tests. Boys outperformed girls in activities requiring muscle strength and power, while girls outperformed boys in activities requiring balance and coordination. The MP scores increased with age for both overarm beanbag throw and standing long jump for both sexes, while the one-leg balance scores showed larger differences between P50 and P95 in older preschoolers. Children with excessive weight performed worse in standing long jump and one-leg balance compared to their healthy weight peers. This study provides valuable information on the MP of preschoolers in Hong Kong, including sex- and age-specific reference values and the association between BMI status and MP scores. These findings can serve as a reference for future studies and clinical practice and highlight the importance of promoting motor skill development in preschoolers, particularly those who are overweight or obese.

Physical Fitness and Body Mass Index Status of Hong Kong Primary Schoolchildren across the COVID-19 Pandemic, before and after School Closure.

OBJECTIVE: To determine whether health-related physical fitness and body mass index (BMI) status differed before and after school closure from the COVID-19 pandemic in a population-based cohort of Hong Kong primary schoolchildren. STUDY DESIGN: We examined the BMI z score, BMI status, and physical fitness z scores including (i) upper limb muscle strength, (ii) 1-minute sit-up test, (iii) sit-and-reach test, and (iv) endurance run tests, among 3 epochs: prepandemic (September 2018-August 2019), before school closure (September 2019-January 2020), and partial school reopening (September 2021-August 2022), using a repeated cross-sectional approach. RESULTS: A total of 137 752 primary schoolchildren aged 6-12 years were recruited over 3 academic years. Obesity increased significantly from 25.9% in 2018/19 to 31.0% in 2021/22, while underweight increased slightly from 6.1% to 6.5%. All tested parameters were adversely affected by the pandemic. The negative trend over time was far more pronounced in all 4 physical fitness scores in the underweight group, although performance in handgrip strength had no significance between 2018/19 and 2021/22. CONCLUSIONS: Schoolchildren who are both underweight and overweight/obese are vulnerable to adverse changes in physical fitness during the COVID-19 pandemic. To eliminate the negative health and fitness outcomes, it is urgent to develop strategies for assisting schoolchildren in achieving a healthy weight, especially in the postpandemic era.

Impact of COVID-19 Pandemic on School-Aged Children's Physical Activity, Screen Time, and Sleep in Hong Kong: A Cross-Sectional Repeated Measures Study.

Despite concerns about the negative effects of social distancing and prolonged school closures on children's lifestyle and physical activity (PA) during the COVID-19 pandemic, robust evidence is lacking on the impact of the pandemic-related school closures and social distancing on children's wellbeing and daily life. This study aimed to examine changes in the PA levels, sleep patterns, and screen time of school-aged children during the different phases of the COVID-19 outbreak in Hong Kong using a repeated cross-sectional design. School students (grades 1 to 12) were asked to report their daily electronic device usage and to fill in a sleep diary, recording their daily sleep onset and wake-up time. They were equipped with a PA monitor, Actigraph wGT3X-BT, to obtain objective data on their PA levels and sleep patterns. Students were recruited before the pandemic (September 2019-January 2020; n = 577), during school closures (March 2020-April 2020; n = 146), and after schools partially reopened (October 2020-July 2021; n = 227). Our results indicated lower PA levels, longer sleep duration, and longer screen time among participants recruited during school closures than those recruited before the COVID-19 outbreak. Primary school students were found to sleep on average for an extra hour during school closures. The later sleep onset and increased screen time documented during school closures persisted when schools partially reopened. Our findings illustrate the significant impact of social distancing policies during the COVID-19 pandemic on the sleep pattern, screen time, and PA level in school-aged children in Hong Kong. Professionals should urgently reinforce the importance of improving physically activity, good sleep hygiene, and regulated use of electronic devices for parents and school-aged children during this unprecedented time.

Gait difference between children aged 9 to 12 with and without potential depressive mood.

BACKGROUND: It has been reported that depression has an impact on both temporal spatial parameters and walking kinematics in adults. Given the difference in the walking biomechanics between adults and children, this study aimed to compare the gait difference in children aged 9-12 with and without potential depressive mood (PDM). METHODS: 49 children were recruited from local primary schools. We measured participants' depression level using Depression Anxiety Stress Scale (DASS) and classified them into control (i.e., DASS depression subscale score = 0.6 ± 1.4; n = 23) or PDM group (i.e., DASS depression subscale score = 21.3 ± 5.3; n = 26). Video gait analysis was employed to assess temporal spatial parameters and sagittal plane kinematics during self-paced overground walking. Independent t tests or Mann-Whitney tests were used to compare the gait parameters between the two groups. RESULTS: Participants exhibited similar gait speed, vertical oscillation of the centre of mass, stance time, swing time, step length, upper and lower limb kinematics between the two groups (p > 0.05). However, children with PDM displayed a greater head flexion than controls (p = 0.026; Cohen's d = 0.66; moderate effect). SIGNIFICANCE: Children with PDM may present a more slumped posture during walking when compared with their counterparts. This kinematics difference can potentially be used as a biomechanical marker for detection of mood problems in this cohort.

Erratum: Lee, R.L.T., et al. Effects of an Unstructured Free Play and Mindfulness Intervention on Wellbeing in Kindergarten Students. Int. J. Environ. Res. Public Health 2020, 17, 5382.

The authors wish to make the following corrections to their paper [...].

Impact of the COVID-19 pandemic on sports and exercise.

BACKGROUND: COVID-19 is a droplet-transmitted potentially fatal coronavirus pandemic affecting the world in 2020. The WHO recommended social distancing and human-to-human contact was discouraged to control the transmission. It has put many countries in a state of lockdown and sporting events (including the 2020 Olympics) have been affected. Participation in sports and exercise, typically regarded as healthy activities, were also debated. The local professional football leagues, governed by the Hong Kong Football Association, ultimately postponed all matches after much deliberation on the transmission risk for the spectators and on-field players. Large spectating crowds are well-known to be infectious hazards, but the infection risk for on-field players is less recognized. Aside from watching professionals exercise, many people opted to hike in the countryside during the weekends to avoid city crowds. This led to a widespread discussion on the issue of wearing a facemask during outdoor activities. METHODS: A small sample of video footage of professional football players were analysed to track each players' time of close body contact and frequency of infection-risky behaviours to investigate the risk of virus transmission during football games.To investigate the physiological effect of wearing a facemask during exercise, we conducted a controlled laboratory, within-subject, repeated measures study of 23 healthy volunteers of various sporting backgrounds. They underwent graded treadmill walking at 4 km per hour for 6 min with and without wearing a surgical mask in a randomized order with sufficient resting time in between trials. The heart rate and the rate of perceived exertion (RPE) were recorded. RESULTS: In a 90 min match, the average duration of close contact between professional football players was 19 min and each player performed an average of 52 episodes of infection-risky behaviours. The heart rate and RPE of subjects wearing a facemask was 128 beats per minute and 12.7 respectively. In those without a facemask, the results were a heart rate of 124 beats per minute and a RPE of 10.8. CONCLUSION: This suggests that the infection risk was high for the players, even without spectators. The laboratory study to investigate the physiological effect of wearing a facemask found that it significantly elevated heart rate and perceived exertion. Those participating in exercise need to be aware that facemasks increase the physiological burden of the body, especially in those with multiple underlying comorbidities. Elite athletes, especially those training for the upcoming Olympics, need to balance and reschedule their training regime to balance the risk of deconditioning versus the risk of infection. The multiple infection-control measures imposed by the Hong Kong national team training centre was highlighted to help strike this balance. Amidst a global pandemic affecting millions; staying active is good, but staying safe is paramount.

Effects of an Unstructured Free Play and Mindfulness Intervention on Wellbeing in Kindergarten Students.

Play is known as the core occupation of young children as it lays a foundation for their early development and physical, emotional and social wellbeing. Literature suggests that unstructured free play and mindfulness interventions may independently promote wellbeing among preschoolers. However, there is no clear evidence of their combination in supporting wellness in early learning environments. We conducted a quasi-experimental study with 42 children aged four to six years, attending two kindergartens in Hong Kong. The intervention included unstructured play with non-directional loose parts (play materials), conducted outdoors for one hour daily followed by a mindfulness intervention for 10 min per day indoors. The intervention lasted for five consecutive days. We examined happiness and aspects of playfulness before and after the intervention, finding a significant increase in all areas. Given greater freedom in play choice, children showed more disruptive behaviors during unstructured play than the control group engaging in recess as usual. We conclude that unstructured play in addition to mindfulness intervention is effective in promoting students' happiness and playfulness, both of which may help maintain mental health and wellbeing amid stressors such as transition and separation. The increased disruptive behavior requires additional investigation.

The reciprocal relationship between body mass index categories and physical fitness: A 4-year prospective cohort study of 20 000 Chinese children.

INTRODUCTION: Body mass index (BMI) categories and physical fitness are associated but the reciprocal relationship between BMI categories and physical fitness has not been investigated. This study aims to investigate the longitudinal reciprocal relationship between BMI categories and physical fitness. METHODS: This is a population-based 4-year cohort study in 48 elementary schools. Children aged 6 to 9 years at recruitment were included. BMI categories and physical fitness including handgrip strength, core muscle endurance, flexibility, and cardiorespiratory fitness were measured using standard equipment and protocol. RESULTS: Among 26 392 eligible participants, 19 504 (73.9%) were successfully followed for 3 years. Baseline obesity prevalence was 5.9%. After 3 years, those who were unfit at baseline had an increased risk of obesity (risk ratio [RR] 1.41, 95% CI 1.16-1.71, P < .001) and those who were fit at baseline had a decreased risk of obesity (RR 0.69, 95% CI 0.60-0.80, P < .001) compared with moderately fit children. Furthermore, improvement of fitness predicted decreased risk of obesity. Similarly, normal body weight also predicted better physical fitness. The path analysis confirmed a strong reciprocal relationship between physical fitness and obesity. CONCLUSIONS: Better physical fitness was prospectively associated with normal weight and vice versa. Physically fit children were more likely to maintain a healthy weight and those with a healthy weight were more likely to be physically fit, which is important for healthy development.

Family carers' experiences of participating in a weight management programme for overweight children and adolescents with intellectual disabilities: An exploratory study.

AIM: To gain insight into the experiences of family carers participating in a weight management programme via mHealth tools for overweight children and adolescents with intellectual disabilities. BACKGROUND: Many weight reduction programs fail to show positive and sustainable impacts due to not involving parents, who are usually unavailable to attend school-based health programs. The mHealth interactive interventions were carried out in September 2015-August 2016, engaging carers to monitor and sustain their children's healthy lifestyle behaviours at home being one way to achieve this. DESIGN: Qualitative research design to conduct focus group discussion with family carers involved in a school-based weight management programme via the mHealth interventions. METHODS: An exploratory study was used to examine family carers' views of participating in a weight management programme. Focus group interviews examined the in-depth experiences of 20 family carers in providing social support and monitoring lifestyle behaviours via the mHealth interactive interventions. RESULTS: Twenty family carers were recruited and four themes emerged: (a) improving family carer-child interactions and communications; (b) gaining useful and practical health information from experts; (c) supporting each other via an mHealth platform; and (d) appreciating the collaborative effort between school personnel and family carers. Family carers stressed the usefulness of the mHealth interactive interventions in monitoring and sustaining the children's healthy lifestyle behaviours at home. CONCLUSION: The mHealth interactive interventions for increasing family carers' involvement and monitoring were well received. The findings provide new insights into using mHealth interventions in future weight management programmes involving parental participation in the home environment.

Childhood Obesity and Physical Activity-Friendly School Environments.

OBJECTIVE: Childhood obesity may be related to school environment, but previous studies often focused on food environment only. This study aimed to examine the relationship between school physical activity environment and childhood obesity. STUDY DESIGN: This is a cross-sectional study with multilevel data collected on school physical activity environment using teacher questionnaires, students' growth, and obesity status from electronic health records, and neighborhood socioeconomic status from census data. RESULTS: This study included 208 280 students (6-18 years of age) from 438 schools (45% of Hong Kong). Prevalence of obesity was 5.0%. After controlling for socioeconomic status and intraschool correlation, robust Poisson regression revealed a reduced obesity risk associated with higher teachers' perceived physical activity benefits (risk ratio 0.96, 95% CI 0.94-0.99, P = .02), physical activity teaching experience (0.93, 0.91-0.96, P < .001), school campus size (0.93, 0.87-0.99, P = .02), physical activity ethos (0.91, 0.88-0.94, P < .001), number of physical activity programs (0.93, 0.90-0.96, P < .001), and physical activity facilities (0.87, 0.84-0.90, P < .001). Students in schools with at least 3 physical activity-friendly environmental factors (11.7%) had a much lower risk of obesity (0.68, 0.62-0.75, P < .001) than those without (23.7%). CONCLUSIONS: A physical activity-friendly school environment is associated with lower risk of obesity. School physical activity environment should be considered in future epidemiologic and intervention studies.

The Impact of a School-Based Weight Management Program Involving Parents via mHealth for Overweight and Obese Children and Adolescents with Intellectual Disability: A Randomized Controlled Trial.

There is a scarcity of resources and studies that utilize targeted weight management interventions to engage parents via mHealth tools targeting obese children and adolescents with mild intellectual disabilities (MIDs) extended from school to a home setting. To test the feasibility and acceptability of a school-based weight program (SBWMP) involving parents via mHealth tools designed to reduce weight, enhance knowledge and adopt healthy lifestyles, and thereby achieve better psychosocial well-being among children and adolescents with MIDs. Four special schools were randomly assigned as intervention or control schools. Students from the intervention group (n = 63) were compared to those in the control group (n = 52), which comprised those with usual school planned activities and no parental involvement. Demographics were considered as covariates in a general linear model, an ordinal regression model and a binary logistic regression model analyzing the relationships between the SBWMP and the outcome variables at baseline (T0) and six months later (T1). Body weight, body mass index, and triceps and subscapular skinfold thickness were lower in the intervention group compared to the control group, although the differences were not statistically significant. There was a positive and direct impact of the SBWMP on students' health knowledge and psychological impacts in the intervention group. The SBWMP extended to the home involving parents via mHealth tools is a feasible and acceptable program for this group with MIDs and their parents.

A Sports-Based Youth Development Program, Teen Mental Health, and Physical Fitness: An RCT.

OBJECTIVES: To assess the effectiveness of a positive youth development (PYD)-based sports mentorship program on the physical and mental well-being of adolescents recruited in a community setting. METHODS: This is a randomized controlled trial in which we recruited students from 12 secondary schools in Hong Kong, China. Participants were randomly assigned in a 1:1 ratio to an intervention or a control arm after stratification for school from October 2013 to June 2014. Participants were not blinded to allocation because of the nature of the intervention. Students in the intervention arm received an after-school, PYD-based sports mentorship for 18 weeks. Each weekly session lasted 90 minutes. Students in the control arm received exclusive access to a health education Web site. RESULTS: Six hundred and sixty-four students (mean age 12.3 years [SD 0.76]; 386 girls [58.1%]) completed baseline and postintervention assessments. The intervention improved students' mental well-being (Cohen's d, 0.25; 95% confidence interval [CI], 0.10 to 0.40; P = .001), self-efficacy (Cohen's d, 0.22; 95% CI, 0.07 to 0.37; P = .01), resilience (Cohen's d, 0.19; 95% CI, 0.03 to 0.34; P = .02), physical fitness (flexibility [Cohen's d, 0.28; 95% CI, 0.13 to 0.43; P = .02], lower limb muscle strength [Cohen's d, 0.18; 95% CI, 0.03 to 0.33; P = .03], and dynamic balance [Cohen's d, 0.21; 95% CI, 0.06 to 0.37; P = .01]), and physical activity levels (Cohen's d, 0.39; 95% CI, 0.24 to 0.55; P < .0001). The intervention did not significantly improve physical well-being (Cohen's d, -0.01; 95% CI, -0.17 to 0.14; P = .86), BMI z scores (Cohen's d, -0.03; 95% CI, -0.18 to 0.12; P = .69), body fat proportion (Cohen's d, -0.15; 95% CI, -0.31 to 0.00; P = .051), and social connectedness (Cohen's d, -0.03; 95% CI, -0.18 to 0.12; P = .72). CONCLUSIONS: A PYD-based sports mentorship intervention improved healthy adolescents' mental well-being, psychological assets, physical fitness, and physical activity levels.

Task-Specific Balance Training Improves the Sensory Organisation of Balance Control in Children with Developmental Coordination Disorder: A Randomised Controlled Trial.

Sensory organisation of balance control is compromised in children with developmental coordination disorder (DCD). A randomised controlled trial involving 88 children with DCD was conducted to evaluate the efficacy of a task-specific balance training (functional-movement training, FMT) programme in improving balance deficits in a DCD population. The DCD participants were randomly assigned to either a FMT group or a control group. The FMT group received two training sessions/ week for 3 months. Measurements of the participants' sensory organisation (somatosensory, vestibular and visual ratios), balance and motor proficiency (Movement Assessment Battery for Children, MABC scores) and center of pressure sway velocity (Unilateral Stance Test, UST scores) were taken at baseline, immediately after FMT and 3 months after FMT. The FMT group showed greater improvements than the controls in somatosensory ratio at 3 and 6 months (all P < 0.001), but the within-group changes were not significant (P > 0.05). The results of both the MABC and the UST also indicated that the balance performance of the FMT group was significantly better than that of the control group at 3 and 6 months (all P < 0.05). Task-specific balance training was found to marginally improve the somatosensory function and somewhat improve the balance performance of children with DCD.

Physical activity improves mental health through resilience in Hong Kong Chinese adolescents.

BACKGROUND: Adolescent mental health problems are global public health concern. Primary prevention through physical activity (PA) has been suggested as a potential approach to tackling this problem. Studies in Western countries have provided some evidence of a relationship between PA and adolescent mental health, but the evidence in China is not sufficient. Furthermore, the mechanism behind this relationship has not been empirically tested. The present study aimed at testing the association between PA and mental well-being of Chinese adolescents and to investigate whether a psychological (self-efficacy and resilience) and social (school and family connectedness) mediation model is valid to explain such a relationship. METHODS: A total of 775 Chinese students in Grades 7 and 8 were recruited in this cross-sectional study. The participants were given questionnaires to assess their PA level, mental well-being, and the potential mediators. Path models were used to analyse the association between PA and mental well-being, and the roles of potential mediators. RESULTS: The PA level was significantly correlated with the adolescent's mental well-being (r = 0.66, p < 0.001), self-efficacy (r = 0.21, p < 0.001), and resilience (r = 0.25, p < 0.001), but not with school connectedness (r = 0.05, p = 0.15) or family connectedness (r = 0.06, p = 0.13). After adjusting for potential confounders in the path model, the PA level was significantly associated with mental well-being (b = 0.52, p < 0.001), and resilience was the only significant mediator (b = 0.31, p < 0.001), which contributed to 60% of this relationship. CONCLUSIONS: There was a significant positive association between the PA level and mental well-being of Chinese adolescents. Resilience mediated the majority of this relationship. Promoting physical activities that build up resilience could be a promising way to improve adolescent mental health.

Difference in children's gross motor skills between two types of preschools.

The purpose of this study was to assess the influence of preschool type (public vs private) on motor skill performance in 239 (121 boys, 118 girls) preschool children ages 3 to 6.5 yr. Preschoolers were tested on 12 fundamental motor skills from the Test of Gross Motor Development-Second Edition and 11 anthropometrics (body height, weight, Body Mass Index, waist and hip girths, and body segment lengths). Analysis of variance controlled for anthropometrics and age indicated that children from private preschools performed better on locomotor skills than those from public preschools. However, no difference was found in object control skills. The results suggest that performance of locomotor skills by preschool children is affected by their schools' physical environment.

Severe Acute Respiratory Syndrome and sport: facts and fallacies.

Severe Acute Respiratory Syndrome (SARS) not only paralysed economic activities in SARS-affected cities, it also affected sporting activities. SARS was identified in Hong Kong in late February 2003 and the WHO issued a global alert on 12 March, 2003. The incubation period of SARS is usually 4-6 days and patients commonly present with high fever (temperature >38 degrees C), dry cough, chills and rigor, dyspnoea and diarrhoea. Although a specific antiviral agent and vaccines for SARS are not available at the time of writing, a standard treatment protocol for SARS has been developed. The average mortality rate is about 16% in Hong Kong.The coronavirus is a common pathogen for upper respiratory tract infection and is the most probable pathogen for SARS. Transmission methods may, therefore, be similar for both these infections. Transmission is possible when aerosolised viral particles come into contact with the susceptible host's mucous membrane, most commonly the nose, but also the mouth and eyes. With appropriate preventive measures to avoid contact with virus, the probability of infection is minimal. Isolation of those who have had close contact with confirmed or suspected SARS patients and/or who have persistent fever will be the most effective and practical method of avoiding contact. Maintaining personal hygiene and frequent hand washing can also reduce the risk of infection. Using diluted bleach (1 part bleach in 99 parts water) to cleanse training areas and equipment is also recommended. With proper event planning to conform with quarantine measures, special travel arrangements, facility sterilisation and use of venues with good ventilation and filtering systems, sport competition can still proceed.