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Abstract Background Increased understanding of why and how physical activity impacts on health outcomes is needed to increase the effectiveness of physical activity interventions. A recent randomized controlled trial of an active video game (PlayStation EyeToy™) intervention showed a statistically significant treatment effect on the primary outcome, change from baseline in body mass index (BMI), which favored the intervention group at 24 weeks. In this short paper we evaluate the mediating effects of the secondary outcomes. Objective To identify mediators of the effect of an active video games intervention on body composition. Methods Data from a two-arm parallel randomized controlled trial of an active video game intervention (n = 322) were analyzed. The primary outcome was change from baseline in BMI. A priori secondary outcomes were considered as potential mediators of the intervention on BMI, including aerobic fitness (VO2Max), time spent in moderate-to-vigorous physical activity (MVPA), and food snacking at 24 weeks. Results Only aerobic fitness at 24 weeks met the conditions for mediation, and was a significant mediator of BMI. Conclusion Playing active video games can have a positive effect on body composition in overweight or obese children and this effect is most likely mediated through improved aerobic fitness. Future trials should examine other potential mediators related to this type of intervention. Trial registration Australian New Zealand Clinical Trials Registry Website: http://www.anzctr.org.au Study ID number: ACTRN12607000632493

Background:Nontailored and static goals may hinder behavior change. We investigated the feasibility and acceptability of an adaptive proof-of-concept smartphone-delivered intervention by using real-world movement data capture of physical activity (PA) and sedentary behavior (SB) to inform behavior change content delivery. Materials and Methods:A single-group 8-week study with pre- and post-intervention assessments was conducted in Auckland, New Zealand. Participants aged 17–69 years who owned an Android smartphone were recruited and used the application (app). Usage data, self-reported acceptability and PA and SB were assessed. Daily repeated measurement of PA and SB outcomes were analyzed through random-effects mixed models. Results:Participants (n = 69) were predominantly female (78%) with a mean age of 34.5 years (range 18–61). On average, participants opened the app on 11.4 days throughout the 8 weeks. Use decreased over time; 20% of participants opened the app every day. Feedback on behavior (73%), behavior substitution (71%), discrepancy between behavior and goal (58%) and goal setting (54%) were rated as the most useful behavior change techniques by participants. Time spent on light, moderate-to-vigorous intensity and total PA increased post-intervention, whereas time spent on SB decreased. Conclusions:The adaptive proof-of-concept app was considered acceptable, with preliminary support for its positive effects on PA and SB. [ABSTRACT FROM AUTHOR]

Background: Numerous school-based interventions for childhood obesity have been emerging in mainland China in recent decades, but little is known about the effectiveness of such interventions. This study aims to assess the effectiveness of school-based interventions for childhood obesity conducted in mainland China. Methods: A systematic search was undertaken in eight databases to identify both randomized and non-randomized controlled trials from January 1990 to December 2015 examining the effectiveness of school-based obesity interventions. A random effects meta-analysis was conducted assessing the impact of included interventions on (body mass index) BMI. The quality of each included studies were assessed using Effective Public Health Practice Project Quality Assessment Tool. A P value <0.05 (two-sided) was considered statistically significant. Result: Of the seventy-six included studies, we found physical activity and health education were the two most common components of interventions. More treatment studies were effective compared with prevention studies (85.0% vs. 58.3%). Comprehensive interventions involving physical activity and health education appeared more effective than the physical activity only interventions in both obesity treatment and prevention studies. The meta-analyses showed comprehensive interventions involving physical activity and health education had larger effect on the change of BMI than physical activity only interventions (treatment studies: -1.80 kg/m2 (95% CI: -2.15,-1.44) vs. -0.91 kg/m2 (95% CI: -1.15,-0.67); prevention studies: -0.19 kg/m2 (95% CI: -0.27, -0.11) vs. +0.05 kg/m2 (95% CI: -0.04, +0.15)). Conclusions: Comprehensive school-based interventions may assist in tackling the rising prevalence of childhood obesity in mainland China. [ABSTRACT FROM AUTHOR]

Objectives: This study sought to better understand the interrelationships between physical activity and sedentary behaviour and the relationship to risk of cardiovascular disease (CVDR) in adults aged 30-75 years.Design: Cross-sectional.Methods: Data from two-year waves (2003-2004 and 2005-2006) of the National Health and Nutritional Examination survey were analysed in 2014. Accelerometer-derived time and proportion of time spent sedentary and on moderate-to-vigorous physical activity (MVPA) were calculated to generate four activity profiles based on cut-points to define low and high levels for the respective behaviours. Using health outcome data, CVDR was calculated for each person. Weighted multiple linear regression models were used to evaluate the predicted effects of sedentary and physical activity behaviours on the CVDR score, adjusting for participants' sex, age group, race, annual household income, and accelerometer wear time.Results: The lowest CVDR was observed among Busy Exercisers (high MVPA and low sedentary; 8.5%), whereas Couch Potatoes (low MVPA and high sedentary) had the highest (18.6%). Compared with the reference group (Busy Exercisers), the activity profile associated with the highest CVDR was Couch Potatoes (adjusted mean difference 3.6, SE 0.38, p<0.0001). A smoothed three-dimensional response surface "risk landscape" was developed to better visualise the conjoint associations of MVPA and sedentary behaviour on CVDR for each activity profile. The association between MVPA was greater than that of sedentary behaviour; however, for people with low MVPA, shifts in sedentary behaviour may have the greatest impact on CVDR.Conclusions: Activity profiles that consider the interrelationships between physical activity and sedentary behaviour differ in terms of CVDR. Future interventions may need to be tailored to specific profiles and be dynamic enough to reflect change in the profile over time. [ABSTRACT FROM AUTHOR]

The aim of the study was to validate the self-report Multimedia Activity Recall for Children and Adolescents (MARCA) against accelerometry for the assessment of physical activity in New Zealand children. Participants (n = 716, 10–18 years) recalled 3–4 days of activity using the MARCA and underwent a partially overlapping 7-day accelerometry protocol during a national survey. Spearman correlation coefficients (ρ) assessed the association between accelerometer-derived counts per minute and MARCA-derived physical activity level and time in locomotion. Both data sources estimated time spent in light and moderate–vigorous physical activity. Association and agreement between methods for light physical activity and moderate–vigorous physical activity was assessed using correlations and Bland–Altman plots respectively, and pairedt-tests conducted. Accelerometer-derived activity counts were moderately correlated with both MARCA-derived physical activity level and locomotion (ρ = 0.38,P < 0.0001). The correlation between methods was –0.14 for light physical activity and 0.28 for moderate–vigorous physical activity (P < 0.0001). The MARCA overestimated moderate–vigorous physical activity compared with accelerometry (120 min,P < 0.0001), which increased as moderate–vigorous physical activity time increased. Some sex and ethnicity (Māori [indigenous] versus non-Māori) differences were observed. Overall, the MARCA indicated moderate validity for assessment of physical activity level, locomotion and moderate–vigorous physical activity and poor validity for assessment of light physical activity. This was comparable to other self-report tools. The MARCA has utility for future large-scale research. [ABSTRACT FROM PUBLISHER]

Abstract: Objective: Low levels of daily energy expenditure (insufficient physical activity and increased sedentary time) have been associated with adverse health outcomes in young people. The Multimedia Activity Recall for Children and Adolescents (MARCA) is a computerized, self-report, use-of-time tool that can assess daily energy expenditure. The study aim was to validate the MARCA for the estimation of energy expenditure in young people, using the criterion standard doubly labeled water. Materials/Methods: Over a 15day assessment period, 32 participants (10–18years) completed the MARCA and underwent a doubly labeled water protocol. Indirect calorimetry was used to assess resting metabolic rate. Total daily energy expenditure (TEE) and activity-related energy expenditure (AEE) were estimated from both the MARCA and doubly labeled water. Association and agreement between methods for TEE and AEE were assessed using Spearman correlations and Bland–Altman plots, respectively. Results: Compared to doubly labeled water, the MARCA over-estimated TEE by an average of 50kcal/day (limits of agreement −1 589 to 1 490kcal/day) and under-estimated AEE 105kcal/day (limits of agreement −1 404 to 1 614kcal/day). The MARCA showed strong correlation with doubly labeled water for TEE (rho=0.70, p<0.0001) and moderate correlation for AEE (rho=0.56, p=0.0009). Conclusions: Overall, the MARCA indicated moderate validity for the assessment of daily TEE and AEE. The wide limits of agreement indicate the MARCA has greater utility for group-level rather than individual-level estimates. [Copyright &y& Elsevier]

Abstract: Background: Most smokers want to stop smoking and many try to quit. However abstinence rates are low and most smokers do not manage to abstain for even a week. Relapse to smoking can be related to the occurrence of tobacco withdrawal symptoms (e.g., sleep disturbance, irritability, and craving) and weight gain. If regular exercise mitigates these effects it could have potential as an aid to smoking cessation. The aim of the Fit2Quit study is to determine the effects of a home and community-based exercise intervention on smoking abstinence at six months when used as an adjunct to usual care (telephone smoking-cessation counseling and nicotine replacement therapy; NRT). Methods/design: A prospective parallel two-arm randomized controlled trial. Participants (n=1400, 700 per arm) will be randomized to a structured home and community-based exercise program plus usual care (behavioral counseling and NRT) or to usual-care alone. It is targeted that at least 25% of the sample will be of Māori ethnicity (New Zealand indigenous). Outcomes to be measured using intention-to-treat analysis include: seven-day point prevalence of smoking abstinence verified by salivary cotinine (primary outcome); 6 months continuous abstinence; body mass index (BMI); cardio-respiratory fitness; physical activity levels; and cost effectiveness. Discussion: The Fit2Quit study is an example of a large, pragmatic randomized controlled trial in a community setting. Specific components of the exercise intervention are outlined in detail. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12609000637246. [ABSTRACT FROM AUTHOR]

Background: Questionnaires are commonly used to assess physical activity in large population-based studies because of their low cost and convenience. Many self-report physical activity questionnaires have been shown to be valid and reliable measures, but they are subject to measurement errors and misreporting, often due to lengthy recall periods. Mobile phones offer a novel approach to measure self-reported physical activity on a daily basis and offer real-time data collection with the potential to enhance recall. Objective: The aims of this study were to determine the convergent validity of a mobile phone physical activity (MobilePAL) questionnaire against accelerometry in people with cardiovascular disease (CVD), and to compare how the MobilePAL questionnaire performed compared with the commonly used self-recall International Physical Activity Questionnaire (IPAQ). Methods: Thirty adults aged 49 to 85 years with CVD were recruited from a local exercise-based cardiac rehabilitation clinic in Auckland, New Zealand. All participants completed a demographics questionnaire and underwent a 6-minute walk test at the first visit. Subsequently, participants were temporarily provided a smartphone (with the MobilePAL questionnaire preloaded that asked 2 questions daily) and an accelerometer, which was to be worn for 7 days. After 1 week, a follow-up visit was completed during which the smartphone and accelerometer were returned, and participants completed the IPAQ. Results: Average daily physical activity level measured using the MobilePAL questionnaire showed moderate correlation (r=.45; P=.01) with daily activity counts per minute (Acc_CPM) and estimated metabolic equivalents (MET) (r=.45; P=.01) measured using the accelerometer. Both MobilePAL (beta=.42; P=.008) and age (beta=-.48, P=.002) were significantly associated with Acc_CPM (adjusted R2=.40). When IPAQ-derived energy expenditure, measured in MET-minutes per week (IPAQ_met), was considered in the predicted model, both IPAQ_met (beta=.51; P=.001) and age (beta=-.36; P=.016) made unique contributions (adjusted R2=.47, F2,27=13.58; P<.001).There was also a significant association between the MobilePAL and IPAQ measures (r=.49, beta=.51; P=.007). Conclusions: A mobile phone-delivered questionnaire is a relatively reliable and valid measure of physical activity in a CVD cohort. Reliability and validity measures in the present study are comparable to existing self-report measures. Given their ubiquitous use, mobile phones may be an effective method for physical activity surveillance data collection. (J Med Internet Res 2013;15(3):e61) [ABSTRACT FROM AUTHOR]