Patrick W.C. Lau

A Systematic review of information and communication technology-based interventions for promoting physical activity behavior change in children and adolescents

Background A growing body of research has employed information and communication technologies (ICTs) such as the Internet and mobile phones for disseminating physical activity (PA) interventions with young populations. Although several systematic reviews have documented the effects of ICT-based interventions on PA behavior, very few have focused on children and adolescents specifically. Objectives The present review aimed to systematically evaluate the efficacy and methodological quality of ICT-based PA interventions for children and adolescents based on evidence from randomized controlled trials. Methods Electronic databases Medline, PsycInfo, CINAHL, and Web of Science were searched to retrieve English language articles published in international academic peer-reviewed journals from January 1, 1997, through December 31, 2009. Included were articles that provided descriptions of interventions designed to improve PA-related cognitive, psychosocial, and behavioral outcomes and that used randomized controlled trial design, included only children (6-12 years old) and adolescents (13-18 years old) in both intervention and control groups, and employed Internet, email, and/or short message services (SMS, also known as text messaging) as one or more major or assistive modes to deliver the intervention. Results In total, 9 studies were analyzed in the present review. All studies were published after 2000 and conducted in Western countries. Of the 9 studies, 7 demonstrated positive and significant within-group differences in at least one psychosocial or behavioral PA outcome. In all, 3 studies reported positive and significant between-group differences favoring the ICT group. When between-group differences were compared across studies, effect sizes were small in 6 studies and large in 3 studies. With respect to methodological quality, 7 of the 9 studies had good methodological quality. Failure to report allocation concealment, blinding to outcome assessment, and lack of long-term follow-up were the criteria met by the fewest studies. In addition, 5 studies measured the intervention exposure rate and only 1 study employed objective measures to record data. Conclusion The present review provides evidence supporting the positive effects of ICTs in PA interventions for children and adolescents, especially when used with other delivery approaches (ie, face-to-face). Because ICT delivery approaches are often mixed with other approaches and these studies sometimes lack a comparable control group, additional research is needed to establish the true independent effects of ICT as an intervention delivery mode. Although two-thirds of the studies demonstrated satisfactory methodological quality, several quality criteria should be considered in future studies: clear descriptions of allocation concealment and blinding of outcome assessment, extension of intervention duration, and employment of objective measures in intervention exposure rate. Due to the small number of studies that met inclusion criteria and the lack of consistent evidence, researchers should be cautious when interpreting the findings of the present review.

Parenting Style and Cultural Influences on Overweight Children's Attraction to Physical Activity

Objective: To investigate the associations among parenting style, gender, Chinese culture, and overweight childrens attraction to physical activity.

Effects of high-intensity intermittent running exercise in overweight children

Abstract This study examined the effects of a 6-week intermittent exercise training, at different intensities, on body composition, functional walking and aerobic endurance in overweight children. Forty-eight overweight children (age: 10.4 ± 0.9 years) were randomly assigned to either intervention or control group. Lower and higher intensity intermittent exercise groups (LIIE and HIIE) performed intermittent running three times a week. LIIE performed more intervals at a lower intensity [16 intervals at 100% of individual maximal aerobic speed (MAS), 8 minutes in total], and HIIE performed fewer intervals at a higher intensity (12 intervals at 120% of MAS, 6 minutes in total). Each interval consisted of a 15-second run at the required speed, followed by a 15-second passive recovery. After 6 weeks, HIIE had a significantly (p < 0.05) higher percentage reduction in sum of skinfolds (i.e. calf and triceps), and significantly (p < 0.05) fewer steps during the functional obstacle performance, as compared with LIIE and control group. Significant improvement (p < 0.05) was found in intermittent aerobic endurance for HIIE as compared to the control group. Higher intensity intermittent training is an effective and time-efficient intervention for improving body composition, functional walking and aerobic endurance in overweight children.

Chronic effects of ambient air pollution on respiratory morbidities among Chinese children: a cross-sectional study in Hong Kong

BackgroundThe chronic health effects from exposure to ambient air pollution are still unclear. This study primarily aims to examine the relationship between long-term exposure to ambient air pollution and respiratory morbidities in Chinese children.MethodsA cross-sectional study was conducted among 2,203 school children aged 8–10 in three districts with different air pollution levels in Hong Kong. Annual means for ambient PM10, SO2, NO2 and O3 in each district were used to estimate participants’ individual exposure. Two questionnaires were used to collect children’s respiratory morbidities and other potential risk factors. Multivariable logistic regression was fitted to estimate the risks of air pollution for respiratory morbidities.ResultsCompared to those in the low-pollution district (LPD), girls in the high-pollution district (HPD) were at significantly higher risk for cough at night (ORadj. = 1.81, 95% CI: 1.71-2.78) and phlegm without colds (ORadj. = 3.84, 95% CI: 1.74-8.47). In addition, marginal significance was reached for elevated risks for asthma, wheezing symptoms, and phlegm without colds among boys in HPD (adjusted ORs: 1.71-2.82), as well as chronic cough among girls in HPD (ORadj. = 2.03, 95% CI: 0.88-4.70).ConclusionsResults have confirmed certain adverse effects on children’s respiratory health from long-term exposure to ambient air pollution. PM10 may be the most relevant pollutant with adverse effects on wheezing and phlegm in boys. Both PM10 and NO2 may be contributing to cough and phlegm in girls.

Effects of short-term resistance training on serum leptin levels in obese adolescents

The purpose of this study was to examine the effects of a short-term resistance training program on serum leptin concentrations in obese adolescents. Eighteen Chinese obese adolescents participated in the supervised weight management program. Resistance training was conducted three times a week on alternate days for 6 weeks. Body composition [body fat mass (FM) and body lean mass (LM)] determined by dual-energy X-ray absorptiometry, muscle strength and leptin, insulin and glucose were measured before and after training. Subjects demonstrated significantly improved strength of leg, chest and bicep under conditions of stability in weight, FM and LM. There were positive correlations between leptin and body mass index, FM, %FM, waist girth and hip girth, and negative correlations between leptin and %L M at the resting state before and after 6 weeks of resistance training. No significant relationship was found between leptin concentration and the parameters of muscular strength or concentrations of insulin and glucose. Compared to pre-training values, serum leptin levels were not significantly altered, while relative leptin (leptin/FM) decreased significantly after the short-term resistance training. These results indicate that short-term resistance training enhances muscle strength but does not alter leptin levels in obese adolescents with weight and FM stability. The results also suggest that 6 weeks of resistance training decreases the requirement of leptin per unit of FM and improves leptin sensitivity in obese adolescents.

Effects of active videogames on physical activity and related outcomes among healthy children: A systematic review

OBJECTIVE This review systematically evaluated the effects of active videogames (AVGs) on physical activity (PA) and related outcomes in healthy children. MATERIALS AND METHODS Electronic databases were searched to retrieve articles published from January 2000 through August 2013. Included were original studies published in English, in peer-reviewed journals, that included at least one subgroup of healthy participants not older than 18 years, and that measured at least one PA-related cognitive, psychosocial, or behavioral outcome. All study designs were included, but only intervention studies with PA comparison between groups or across time were assessed for methodological quality. Evidence strength for intervention studies was stratified by settings (including the free-living home setting, the school, community, or primary care setting with structured AVG sessions [i.e., AVG play of participants was organized by teachers or researchers], and multiple settings). RESULTS Fifty-four articles were identified, including 32 studies that examined the immediate PA effects (i.e., energy expenditure and PA levels during AVG play), one survey study, and 21 intervention studies aimed to promote PA. AVGs led to light- to moderate-intensity PA among studies of immediate PA outcomes. No effect was identified of AVGs on PA in the home setting. Moderate evidence was found that structured AVG play could improve PA. Inconclusive evidence was found for the effect of AVGs on PA in multiple settings. CONCLUSIONS The present review does not support using AVGs alone in the home setting to promote PA. Structured AVG play has the potential to promote PA in children.

BMI-for-age Z-score distribution shifts among Chinese children: Gender disparity

To identify gender differences among Chinese school‐aged children from 1995 to 2010, and to project the future BMI‐for‐age Z‐score distribution and prevalence of obesity.

The association between global self-esteem, physical self-concept and actual vs ideal body size rating in Chinese primary school children.

OBJECTIVE: To investigate whether the discrepancy between actual and ideal body size rating is related to Chinese childrens global self-esteem and global physical self-concept.DESIGN: A cross-sectional study of school children who completed questionnaires related to global self-esteem, global physical self-concept, and actual vs ideal body size.SUBJECTS: A total of 386 Chinese children (44% girls and 56% boys) aged 7–13 y from a primary school in Hong Kong, China.MEASUREMENTS: Global self-esteem and physical self-concept were measured using the physical self-descriptive questionnaire. Actual vs ideal body size discrepancy was established using the silhouette matching task.RESULTS: No significant relationship was found between global self-esteem and actual–ideal body size discrepancy of children. Global physical self-concept had a moderate negative correlation (r=−0.12) with the body size discrepancy score and the discrepancy score explained very limited variance (R 2=0.015; F(1, 296)=4.51; P<0.05) in global physical self-concept. Three body size discrepancy groups (none, positive, and negative) were examined to see if there were any significant differences in global self-esteem, global physical self-concept, and specific dimensions of physical self-concept. A significant overall difference was found between groups for global physical self-concept (F=3.73, P<0.05) and the physical self-concept subscales of physical activity (F=3.25, P<0.05), body fat (F=61.26, P<0.001), and strength (F=5.26, P<0.01). Boys scored significantly higher than girls on global physical self-concept—especially in the sport competence, strength, and endurance subscales.CONCLUSION: This study revealed that the actual–ideal body size discrepancy rating of Chinese children was not predictive of global physical self-concept and global self-esteem. These findings are contrary to those reported in Western children, which may mean that culture plays a role in the formation of body attitude.

Secular trends in age at menarche among Chinese girls from 24 ethnic minorities, 1985 to 2010

Background Declining age at menarche has been observed in many countries. In China, a decrease of 4.5 months per decade in the average age at menarche among the majority Han girls has recently been reported. However, the trends in age at menarche among ethnic minority girls over the past 25 years remain unknown. Objectives To compare the differences in median age at menarche among girls aged 9–18 years across 24 ethnic minorities in 2010 and to estimate the trends in age at menarche in different ethnic minorities from 1985 to 2010. Design We used data from six cross-sectional Chinese National Surveys on Students’ Constitution and Health (1985, 1991, 1995, 2000, 2005, and 2010). The median age at menarche was estimated by using probit analysis. Results In 2010, the ethnic minorities with the earliest age at menarche were the Koreans (11.79 years), Mongolians (12.44 years), and Zhuang (12.52 years). The three ethnic minorities with the latest age at menarche were the Sala (14.32 years), Yi (13.74 years), and Uighurs (13.67 years). From 1985 to 2010, the age at menarche declined in all 24 minority groups. The Lisu, Kazakh, and Korean minorities showed the largest reductions in age at menarche by 1.79 (p<0.05), 1.69 (p<0.05), and 1.57 (p<0.05) years, respectively, from 1985 to 2010. The Yi, Sala, and Li minorities showed the smallest reductions, with age at menarche declining by only 0.06 (p>0.05), 0.15 (p>0.05), and 0.15 (p>0.05) years, respectively, in the same period. Conclusion A large variation in age at menarche was observed among different ethnic minorities, with the earliest age at menarche found among Korean girls. A reduction in the average age at menarche appeared among most of the ethnic minorities over time, and the largest decrease was observed in Lisu, Kazakh, and Korean girls. Thus, health education should focus on targeting the specific needs of each ethnic minority group.

The Longitudinal Changes of National Identity in Mainland China, Hong Kong and Taiwan Before, During and After the 2008 Beijing Olympics Games

The present study examined longitudinal changes in Asian (i.e. Mainland China, Hong Kong and Taiwan) school students’ national identity before, during and after the 2008 Beijing Olympics. Participants were 946 secondary students aged 12–17 years from Mainland China, Hong Kong and Taiwan. This study revealed that residence, especially the hosting city, acted as the most significant factor in longitudinal changes and contribution to the national identity among the three regions. The time factor (before, during and after the Games) was only significant when it interacted with residence. These findings suggest that residence (hosting city) provided the greatest contribution in national identity before, during and after the 2008 Beijing Olympic Games.