The association between the activity profile and cardiovascular risk.

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.

Results from New Zealand's 2014 report card on physical activity for children and youth

BACKGROUND: This brief report provides grades for the 2014 New Zealand Report Card on Physical Activity for Children and Youth. The Report Card presents a review of current evidence across 9 key indicators, including physical activity (PA), organized sport and free play, sedentary behavior, and community and government initiatives across New Zealand. METHODS: Nationally representative survey data were collated by researchers at the University of Auckland, New Zealand, between June and December 2013. The grade for each indicator is based on the percentage of children and youth meeting a defined benchmark: A is 81%-100%; B is 61%-80%; C is 41%-60%, D is 21%-40%; F is 0%-20%; INC is incomplete data. RESULTS: Overall PA received a score of B, as did Organized Sport Participation and Active Play. PA participation in School Environment scored slightly less with a score of B-. Sedentary Behaviors, Family and Peers, and Community and Built Environment scored a grade of C. Active transportation received a score of C-. An inconclusive grade was given for the Government indicator due to a lack of established international criteria for assessment. CONCLUSIONS: PA participation in New Zealand is satisfactory, but could improve. However, sedentary behavior is high. Of particular concern is the age-related decline in PA participation, particularly among adolescent females, and the increase in sedentary behavior.

Screen-time weight-loss intervention targeting children at home (SWITCH): a randomized controlled trial

BACKGROUND: Screen-based activities, such as watching television (TV), playing video games, and using computers, are common sedentary behaviors among young people and have been linked with increased energy intake and overweight. Previous home-based sedentary behaviour interventions have been limited by focusing primarily on the child, small sample sizes, and short follow-up periods. The SWITCH (Screen-Time Weight-loss Intervention Targeting Children at Home) study aimed to determine the effect of a home-based, family-delivered intervention to reduce screen-based sedentary behaviour on body composition, sedentary behaviour, physical activity, and diet over 24 weeks in overweight and obese children.

METHODS: A two-arm, parallel, randomized controlled trial was conducted. Children and their primary caregiver living in Auckland, New Zealand were recruited via schools, community centres, and word of mouth. The intervention, delivered over 20 weeks, consisted of a face-to-face meeting with the parent/caregiver and the child to deliver intervention content, which focused on training and educating them to use a wide range of strategies designed to reduce their child's screen time. Families were given Time Machine TV monitoring devices to assist with allocating screen time, activity packages to promote alternative activities, online support via a website, and monthly newsletters. Control participants were given the intervention material on completion of follow-up. The primary outcome was change in children's BMI z-score from baseline to 24 weeks.

RESULTS: Children (n = 251) aged 9-12 years and their primary caregiver were randomized to receive the SWITCH intervention (n = 127) or no intervention (controls; n = 124). There was no significant difference in change of zBMI between the intervention and control groups, although a favorable trend was observed (-0.016; 95% CI: -0.084, 0.051; p = 0.64). There were also no significant differences on secondary outcomes, except for a trend towards increased children's moderate intensity physical activity in the intervention group (24.3 min/d; 95% CI: -0.94, 49.51; p = 0.06).

CONCLUSIONS: A home-based, family-delivered intervention to reduce all leisure-time screen use had no significant effect on screen-time or on BMI at 24 weeks in overweight and obese children aged 9-12 years.

The effect of active video games by ethnicity, sex and fitness: subgroup analysis from a randomised controlled trial

BACKGROUND: The prevention and treatment of childhood obesity is a key public health challenge. However, certain groups within populations have markedly different risk profiles for obesity and related health behaviours. Well-designed subgroup analysis can identify potential differential effects of obesity interventions, which may be important for reducing health inequalities. The study aim was to evaluate the consistency of the effects of active video games across important subgroups in a randomised controlled trial (RCT).

FINDINGS: A two-arm, parallel RCT was conducted in overweight or obese children (n=322; aged 10-14 years) to determine the effect of active video games on body composition. Statistically significant overall treatment effects favouring the intervention group were found for body mass index, body mass index z-score and percentage body fat at 24 weeks. For these outcomes, pre-specified subgroup analyses were conducted among important baseline demographic (ethnicity, sex) and prognostic (cardiovascular fitness) groups. No statistically significant interaction effects were found between the treatment and subgroup terms in the main regression model (p=0.36 to 0.93), indicating a consistent treatment effect across these groups.

CONCLUSIONS: Preliminary evidence suggests an active video games intervention had a consistent positive effect on body composition among important subgroups. This may support the use of these games as a pragmatic public health intervention to displace sedentary behaviour with physical activity in young people.

Validation of a computerized use of time recall for activity measurement in advanced-aged adults

BACKGROUND: The Multimedia Activity Recall for Children and Adults (MARCA) is a computerized recall instrument that records use of time during 24 hr the previous day and has been developed to address limitations of current self-report physical activity measures for those in advanced age. METHODS: Test-retest reliability and convergent validity of the adult MARCA were assessed in a sample of 45 advanced-age adults (age 84.9 SD ± 1.62 yr) as a subsample of the Life and Living in Advanced-Age Cohort Study New Zealand (LiLACS NZ). Test-retest methods required participants to recall the previous day's activity using the MARCA twice within the same day. Convergent validity was assessed against accelerometry. RESULTS: Test-retest reliability was high, with ICCs greater than .99 for moderate to vigorous physical activity (MVPA) and physical activity level (PAL). Compared with accelerometry, the MARCA demonstrated validity comparable to other self-report instruments with Spearman's coefficients of .34 and .59 for time spent in nonsedentary physical activity and PAL. CONCLUSION: The MARCA is a valid and reliable self-report tool for physical activity behaviors in advanced-age adults.

Presleep activities and time of sleep onset in children

OBJECTIVE: Presleep activities have been implicated in the declining sleep duration of young people. A use-of-time approach may be used to describe the presleep period. The study aims were to describe the activities undertaken 90 minutes before sleep onset and to examine the association between activities and time of sleep onset in New Zealand young people. METHODS: Participants (N = 2017; 5-18 years) self-reported their time use as part of a national survey. All activities reported in the 90 minutes before sleep were extracted. The top 20 activities were grouped into 3 behavioral sets: screen sedentary time, nonscreen sedentary time, and self-care. An adjusted regression model was used to estimate presleep time spent in each behavioral set for 4 distinct categories of sleep onset (very early, early, late, or very late), and the differences between sleep onset categories were tested. RESULTS: In the entire sample, television watching was the most commonly reported activity, and screen sedentary time accounted for ∼30 minutes of the 90-minute presleep period. Participants with a later sleep onset had significantly greater engagement in screen time than those with an earlier sleep onset. Conversely, those with an earlier sleep onset spent significantly greater time in nonscreen sedentary activities and self-care. CONCLUSIONS: Screen sedentary time dominated the presleep period in this sample and was associated with a later sleep onset. The development of interventions to reduce screen-based behaviors in the presleep period may promote earlier sleep onset and ultimately improved sleep duration in young people.

Children and television watching: a qualitative study of New Zealand parents' perceptions and views

BACKGROUND: Television (TV) viewing is one of the most pervasive sedentary pursuits among children and adolescents. Research studies have shown that higher TV viewing hours are associated with a number of negative effects such as being overweight and obese, attention and behavioural problems, and impaired academic performance. Most interventions to reduce time spent watching TV have been school-based and little is known about the strategies that families use to control TV watching time. METHODS: Six focus groups with Māori, Pacific and non-Māori non-Pacific parents were conducted to examine New Zealand parents' perceptions of their children's TV watching. Focus groups explored attitudes towards TV viewing, strategies used to reduce viewing, and opinion on two different electronic monitors that can be used to restrict TV viewing. Focus group discussions were transcribed and a content analysis was conducted. RESULTS: Parents described TV as playing a dominant role in their family's lives, and highlighted several barriers to reducing children's TV viewing, such as parents not willing to reduce their own TV watching, a lack of safe alternatives to TV and the need to use TV as a babysitting tool. Limiting access to TV, making TV viewing a reward and finding alternative activities were current strategies parents employed to limit TV viewing; however, the barriers highlighted by parents make implementing such strategies difficult. Attitudes towards electronic monitor use to reduce TV viewing were mixed, but suggest further investigation of these devices is needed. CONCLUSIONS: Electronic devices that restrict the amount and content of TV viewing have some potential to support interventions and merit further investigation. It is imperative for interventions aimed at reducing TV viewing to consider the role TV plays within a family context, ensuring parental perceptions around the benefits and barriers of reducing TV are accounted for.

Use of active video games to increase physical activity in children: a (virtual) reality?

There has been increased research interest in the use of active video games (in which players physically interact with images onscreen) as a means to promote physical activity in children. The aim of this review was to assess active video games as a means of increasing energy expenditure and physical activity behavior in children. Studies were obtained from computerized searches of multiple electronic bibliographic databases. The last search was conducted in December 2008. Eleven studies focused on the quantification of the energy cost associated with playing active video games, and eight studies focused on the utility of active video games as an intervention to increase physical activity in children. Compared with traditional nonactive video games, active video games elicited greater energy expenditure, which was similar in intensity to mild to moderate intensity physical activity. The intervention studies indicate that active video games may have the potential to increase free-living physical activity and improve body composition in children; however, methodological limitations prevent definitive conclusions. Future research should focus on larger, methodologically sound intervention trials to provide definitive answers as to whether this technology is effective in promoting long-term physical activity in children.

Effects of resistance or aerobic exercise training on interleukin-6, C-reactive protein, and body composition

PURPOSE: To determine the effects of 10 wk of resistance or aerobic exercise training on interleukin-6 (IL-6) and C-reactive protein (CRP). Further, to determine pretraining and posttraining associations between alterations of IL-6 and CRP and alterations of total body fat mass (TB-FM), intra-abdominal fat mass (IA-FM), and total body lean mass (TB-LM). METHODS: A sample of 102 sedentary subjects were assigned to a resistance group (n = 35), an aerobic group (n = 41), or a control group (n = 26). Before and after intervention, subjects were involved in dual-energy x-ray absorptiometry, muscular strength and aerobic fitness, measurements and further provided a resting fasted venous blood sample for measures of IL-6, CRP, cholesterol profile, triglycerides, glucose, insulin, and glycosylated hemoglobin. The resistance and the aerobic groups completed a respective 10-wk supervised and periodized training program, whereas the control group maintained sedentary lifestyle and dietary patterns. RESULTS: Both exercise training programs did not reduce IL-6; however, the resistance and the aerobic groups reduced CRP by 32.8% (P < 0.05) and 16.1% (P = 0.06), respectively. At baseline, CRP was positively correlated with IL-6 (r = 0.35), (TB-FM) (r = 0.36), and IA-FM (r = 0.31) and was inversely correlated with aerobic fitness measures (all r values > or = -0.24). Compared with the resistance and the control groups, the aerobic group exhibited significant (P < 0.05) improvements in all aerobic fitness measures and significant reductions in IA-FM (7.4%) and body mass (1.1%). Compared with the aerobic and the control groups, the resistance group significantly (P < 0.05) improved TB-FM (3.7%) and upper (46.3%) and lower (56.6%) body strength. CONCLUSION: Despite no alteration in baseline IL-6 and significantly smaller reductions in measures of adipose tissue as compared with the aerobic training group, only resistance exercise training resulted in significant attenuation of CRP concentration.

Neighbourhood environment, physical activity, quality of life and depressive symptoms in Hong Kong older adults: a protocol for an observational study

INTRODUCTION: The neighbourhood environment can assist the adoption and maintenance of an active lifestyle and affect the physical and mental well-being of older adults. The psychosocial and behavioural mechanisms through which the environment may affect physical and mental well-being are currently poorly understood. AIM: This observational study aims to examine associations between the physical and social neighbourhood environments, physical activity, quality of life and depressive symptoms in Chinese Hong Kong older adults.

METHODS AND ANALYSES: An observational study of the associations of measures of the physical and social neighbourhood environment, and psychosocial factors, with physical activity, quality of life and depressive symptoms in 900 Hong Kong older adults aged 65+ years is being conducted in 2012-2016. The study involves two assessments taken 6 months apart. Neighbourhood walkability and access to destinations are objectively measured using Geographic Information Systems and environmental audits. Demographics, socioeconomic status, walking for different purposes, perceived neighbourhood and home environments, psychosocial factors, health status, social networks, depressive symptoms and quality of life are being assessed using validated interviewer-administered self-report measures and medical records. Physical functionality is being assessed using the Short Physical Performance Battery. Physical activity and sedentary behaviours are also being objectively measured in approximately 45% of participants using accelerometers over a week. Physical activity, sedentary behaviours, quality of life and depressive symptoms are being assessed twice (6 months apart) to examine seasonality effects on behaviours and their associations with quality of life and depressive symptoms.

ETHICS AND DISSEMINATION: The study received ethical approval from the University of Hong Kong Human Research Ethics Committee for Non-Clinical Faculties (EA270211) and the Department of Health (Hong Kong SAR). Data are stored in a password-protected secure database for 10 years, accessible only to the named researchers. Findings will be submitted for publication in peer-reviewed journals.

Objectively measured sedentary time, physical activity, and metabolic risk the Australian diabetes, obesity and lifestyle tudy (AusDiab)

OBJECTIVE—We examined the associations of objectively measured sedentary time and physical activity with continuous indexes of metabolic risk in Australian adults without known diabetes.

RESEARCH DESIGN AND METHODS—An accelerometer was used to derive the percentage of monitoring time spent sedentary and in light-intensity and moderate-to-vigorous–intensity activity, as well as mean activity intensity, in 169 Australian Diabetes, Obesity and Lifestyle Study (AusDiab) participants (mean age 53.4 years). Associations with waist circumference, triglycerides, HDL cholesterol, resting blood pressure, fasting plasma glucose, and a clustered metabolic risk score were examined.

RESULTS—Independent of time spent in moderate-to-vigorous–intensity activity, there were significant associations of sedentary time, light-intensity time, and mean activity intensity with waist circumference and clustered metabolic risk. Independent of waist circumference, moderate-to-vigorous–intensity activity time was significantly beneficially associated with triglycerides.

CONCLUSIONS—These findings highlight the importance of decreasing sedentary time, as well as increasing time spent in physical activity, for metabolic health.

The dietary, physical activity and sedentary behaviours of Victorian regional secondary school students

The aim of this study was to investigate the dietary, physical activity and sedentary behaviours of adolescents from four secondary schools in Warrnambool, regional Victoria. In 2004, a random sample of students (n=712), stratified by school year level, was generated from school enrolment databases and 443 students completed a lifestyle questionnaire. Twenty per cent of students were physically active for 60 minutes or more per day; 28 per cent used electronic media in free time for a maximum of two hours per day. Only seven per cent of students met these two Australian physical activity recommendations. Fruit, vegetables and dairy products were consumed every day by 39 per cent, 40 per cent and 71 per cent of students respectively; three serves per day of each of these foods are recommended for Australian adolescents. Compared with boys, girls were less physically active (p<0.001), consumed more fruit (p=0.011) and vegetables (p<0.001), but fewer dairy products (p<0.024). Seventeen per cent of students were overweight or obese; these students were less physically active than normal weight peers (p<0.018). The dietary, physical and sedentary behaviours of regional Victorian secondary school students in this study were inadequate when compared with Australian recommendations. Dietary and physical activity habits are still evolving in adolescence and unhealthy habits can still be changed.

Overweight and obesity in Australia: the 1999-2000 Australian Diabetes, Obesity and Lifestyle Study (AusDiab)

Objective:
To measure the prevalence of obesity in Australian adults and to examine the associations of obesity with socioeconomic and lifestyle factors.

Design:
AusDiab, a cross-sectional study conducted between May 1999 and December 2000, involved participants from 42 randomly selected districts throughout Australia.

Participants:
Of 20 347 eligible people aged > 25 years who completed a household interview, 11 247 attended the physical examination at local survey sites (response rate, 55%).

Main outcome measures:
Overweight and obesity defined by body mass index (BMI; kg/m2) and waist circumference (cm); sociodemographic factors (including smoking, physical activity and television viewing time).

Results:
The prevalence of overweight and obesity (BMI > 25.0 kg/m2; waist circumference > 80.0 cm [women] or > 94.0 cm [men]) in both sexes was almost 60%, defined by either BMI or waist circumference. The prevalence of obesity was 2.5 times higher than in 1980. Using waist circumference, the prevalence of obesity was higher in women than men (34.1% v 26.8%; P < 0.01). Lower educational status, higher television viewing time and lower physical activity time were each strongly associated with obesity, with television viewing time showing a stronger relationship than physical activity time.

Conclusions:
The prevalence of obesity in Australia has more than doubled in the past 20 years. Strong positive associations between obesity and each of television viewing time and lower physical activity time confirm the influence of sedentary lifestyles on obesity, and underline the potential benefits of reducing sedentary behaviour, as well as increasing physical activity, to curb the obesity epidemic.

A culturally appropriate diet and lifestyle intervention can successfully treat the components of metabolic syndrome in female Pakistani immigrants residing in Melbourne, Australia

This study was designed to test the effectiveness of a culturally appropriate diet and lifestyle intervention to treat metabolic syndrome in female Pakistani immigrants residing in Melbourne, Australia. Forty Pakistani women with metabolic syndrome (aged 20-50 years) completed a 12-week culturally appropriate diet and exercise program. Results indicate that, before intervention, participants were sedentary, taking 4000 ± 22.6 steps per day, and had an obese-classified body mass index (BMI) of 29.2 ± 0.46 kg/m2 (BMI was categorized in accordance with guidelines specifically designed for Asians) and high waist circumference of 132 ± 25.95 cm. Participants were hypertensive (systolic, 135 ± 1.3 mm Hg; diastolic, 86 ± 0.68 mm Hg), were dyslipidemic (total cholesterol, 6.8 ± 0.15 mmol/L; triglycerides, 2.9 ± 0.09 mmol/L), and had elevated blood glucose (6.4 ± 0.33 mmol/L) and fasting blood insulin (45 ± 6.3 μU/mL) levels. After the 12-week culturally appropriate intervention, activity increased (8600 ± 596.7 steps per day, P < .05); and BMI (27.8 ± 0.45 kg/m2), blood pressure (systolic, 125 ± 1.4 mm Hg; diastolic, 80 ± 0.6 mm Hg), cholesterol (5.5 ± 0.1 mmol/L), blood glucose (5.9 ± 0.33 mmol/L), and blood insulin (24.14 ± 1.8 μU/mL) levels were all significantly reduced (P < .05). This study revealed that the Pakistani female migrants who had metabolic syndrome and its components can successfully be treated via a culturally appropriate diet and lifestyle intervention. The success of the current program raises the possibility that other high-risk ethnic groups can also be treated with a culturally appropriate program.