Impact on hemostatic parameters of interrupting sitting with intermittent activity

Introduction: Excessive sitting has been associated with an elevated risk of vascular conditions, particularly venous thrombosis. Interrupting sitting time with intermittent physical activity can reduce venous stasis; however, impacts on other aspects of thrombogenesis are less understood. Purpose: To examine the effects of interrupting sitting time on blood coagulation and blood volume parameters in sedentary, middle-age, overweight/obese adults (11 men and 8 women; age = 53.8 T 4.9 yr, body mass index = 31.2 T 4.1 kgImj2; mean T SD). Methods: The randomized three-period, three-treatment acute crossover trial consisted of uninterrupted sitting and sitting interrupted by 2-min bouts of either light- or moderate-intensity treadmill walking every 20 min. In each trial condition, blood samples were collected at baseline before the consumption of a standardized meal (j2 h) and postintervention (5 h). Results: Plasma fibrinogen increased from baseline with uninterrupted sitting (0.24 gILj1, 95% confidence interval = 0.13–0.34, P G 0.001). Lightintensity but not moderate-intensity activity breaks attenuated the increase by 0.17 gILj1 (95% confidence interval = 0.01–0.32, P G 0.05). There were no between-condition differences in prothrombin time, activated partial thromboplastin time, von Willebrand
factor, D-dimer, or platelet count. Uninterrupted sitting reduced plasma volume and increased hematocrit, hemoglobin, and red blood cell count; effects attenuated by both light- and moderate-intensity breaks (P G 0.05). White blood cell count increased with uninterrupted sitting and further increased with moderate-intensity breaks. Mean platelet volume increased with moderate-intensity but not lightintensity breaks or uninterrupted sitting. Conclusion: Uninterrupted sitting increased fibrinogen and reduced plasma volume, with associated increases in hemoglobin and hematocrit. Activity breaks attenuated these responses, indicative of an ameliorating influence on the procoagulant effects of uninterrupted sitting.

Correlates of change in adults’ television viewing time : a four-year follow-up study

Purpose: Adults tend to increase their television (TV) viewing time as they age, but little is known about attributes associated with change in TV viewing over time. This study examined individual, social, and environmental correlates of change in TV viewing time for 4 yr.

Methods: Adult participants (n = 897) from a longitudinal epidemiological study in Adelaide, Australia, reported TV viewing time at baseline (2003–2004) and at follow- up (2007–2008). Generalized linear modeling was used to examine correlates of change in TV viewing time.

Results: The mean TV viewing time increased from 112 to 116 min·d-1 from baseline to follow-up. Adjusted for TV viewing time at baseline, having a tertiary education was associated with a 13% lower TV time at follow-up (P = 0.007). Each additional hour of occupational and transport physical activity at baseline was associated with a 2% and 7% lower TV viewing at follow-up (P = 0.031 and P = 0.023, respectively). For men, an additional hour of domestic physical activity was associated with a 7% higher TV viewing time at follow-up (P = 0.006). A significant neighborhood walkability × working status interaction (P = 0.035) indicated that, for those who were not working, living in a highly walkable neighborhood was associated with a 23% lower TV viewing time at follow-up (P = 0.003).

Conclusions: Adults with lower educational attainment, adults with lower occupational and transport physical activity, men with higher domestic physical activity, and nonworking adults living in lowly walkable neighborhoods were at higher risk of increase in TV viewing time. Interventions should target multiple variables at the individual, social, and environmental levels to address age-related increases in TV viewing time.

Physical activity for cancer survivors : a meta-analysis of randomised controlled trials

Objective To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer. Design Meta-analysis of randomised controlled trials with data extraction and quality assessment performed independently by two researchers. Data sources Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews. Study selection Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment. Results There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions. Conclusions Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power output, and improved quality of life.

Television viewing time of colorectal cancer survivors is associated prospectively with quality of life

Objective : To examine prospective associations of television viewing time with quality of life, following a colorectal cancer diagnosis.

Methods : One thousand, nine hundred and sixty-six colorectal cancer survivors were recruited through the Queensland Cancer Registry. Interviews were conducted at 5, 12, 24, and 36 months post-diagnosis. Generalized linear mixed models estimated the effects of television viewing time on quality of life.

Results : Participants who watched ≥5 h of television per day had a 16% lower total quality of life score than did participants reporting ≤2 h per day. Deleterious associations of television viewing time were found with all quality of life subscales: functional well-being showed the strongest association (23% difference in quality of life scores between highest and lowest television viewing categories), and social well-being the weakest association (6% difference). Participants who increased their television viewing by one category (e.g., ≤2 h, increasing to 3–4 h per day) had a proportional decrease of some 6% in their quality of life score (intra-individual effect).

Conclusions : The deleterious associations of television viewing time with quality of life were clinically significant and consistent over time. Decreasing sedentary behavior may be an important behavioral strategy to enhance the quality of life of cancer survivors.

Active video games for youth : a systematic review

Background: A population level increase in physical activity (PA) is critical to reduce obesity in youth. Video games are highly popular and active video games (AVGs) have the potential to play a role in promoting youth PA.

Method: Studies on AVG play energy expenditure (EE) and maintenance of play in youth were systematically identified in the published literature and assessed for quality and informational value.

Results: Nine studies measuring AVG play EE were identified. The meta-analytic estimates of average METs across these studies were 3.1 (95% CI: 2.6, 3.6) to 3.2 (95% CI: 2.7, 3.7). No games elicited an average EE above the 6 MET threshold for vigorous EE. Observed differences between studies were likely due to the different types of games used, rather than age or gender. Four studies related to maintenance of play were identified. Most studies reported AVG use declined over time. Studies were of low-to-medium quality.

Conclusion: AVGs are capable of generating EE in youth to attain PA guidelines. Few studies have assessed sustainability of AVG play, which appears to diminish after a short period of time for most players. Better-quality future research must address how AVG play could be maintained over longer periods of time.

Adolescents’ physical activity : competition between perceived neighborhood sport facilities and home media resources

Objective. To examine the independent, competing, and interactive effects of perceived availability of specific types of media in the home and neighborhood sport facilities on adolescents’ leisure-time physical activity (PA).

Methods. Survey data from 34 369 students in 42 Hong Kong secondary schools were collected (2006–07). Respondents reported moderate-to-vigorous leisure-time PA, presence of sport facilities in the neighborhood and of media equipment in the home. Being sufficiently physically active was defined as engaging in at least 30 minutes of non-school leisure-time PA on a daily basis. Logistic regression and post-estimation linear combinations of regression coefficients were used to examine the independent and competing effects of sport facilities and media equipment on leisure-time PA.

Results. Perceived availability of sport facilities was positively (ORboys = 1.17; ORgirls = 1.26), and that of computer/Internet negatively (ORboys = 0.48; ORgirls = 0.41), associated with being sufficiently active. A significant positive association between video game console and being sufficiently active was found in girls (ORgirls = 1.19) but not in boys. Compared with adolescents without sport facilities and media equipment, those who reported sport facilities only were more likely to be physically active (ORboys = 1.26; ORgirls = 1.34), while those who additionally reported computer/Internet were less likely to be physically active (ORboys = 0.60; ORgirls = 0.54).

Conclusions. Perceived availability of sport facilities in the neighborhood may positively impact on adolescents’ level of physical activity. However, having computer/Internet may cancel out the effects of active opportunities in the neighborhood. This suggests that physical activity programs for adolescents need to consider limiting the access to computer-mediated communication as an important intervention component.

Exploration strategies map along fast-slow metabolic and life-history continua in muroid rodents

1Personality is highly relevant to ecology and the evolution of fast–slow metabolic and life-history strategies. One of the most important personality traits is exploratory behaviour, usually measured on an animal introduced to a novel environment (e.g. open-field test).2Here, we use a unique comparative dataset on open-field exploratory behaviour of muroid rodents to test a key assumption of a recent evolutionary model, i.e. that exploration thoroughness is positively correlated to age at first reproduction (AFR). We then examine how AFR and exploratory behaviour are related to basal metabolic rate (BMR).3Inter-specific variation in exploratory behaviour was positively correlated with AFR. Both AFR and exploration behaviour were negatively correlated with BMR. These results remained significant when taking phylogeny into account.4We suggest that species occupying unproductive and unpredictable environments simultaneously benefit from high exploration, low BMR and delayed AFR because exploration increases the likelihood of finding scarce resources, whereas low BMR and delayed reproduction enhance survival during frequent resources shortages.5This study provides the first empirical evidence for a link between personality, life-history, phylogeny and energy metabolism at the inter-specific level. The superficial-thorough exploration continuum can be mapped along the fast–slow metabolic and life-history continua.

Community-based efforts to prevent obesity: Australia-wide survey of projects

Issues addressed: 

Triple G girls get going in tennis : resource manual

Physical activity is ranked second in importance only to tobacco control in health promotion and disease prevention in Australia. Individuals can be active in many ways every day, including –walking to and/or from school, work and other places of interest; participating in sports clubs; going to the YMCA or community leisure centre where you can be active through gyms, group fitness classes or in the swimming pool; visiting local parks and walking trails, and even at home and in the backyard. You can always find ways to be active in the community.

Promoting physical activity to young people is important for developing healthy lifestyles now and maintaining them for the future. A physically active lifestyle can be of benefit to physical, mental and social health. Despite these benefits, adolescent girls and young women are considerably less active than their male counterparts, and sport participation decreases dramatically among girls during their secondary school years. Many physical education teachers have also expressed concern about girls minimising their participation in school physical education. Consequently, it is timely that a project such as Triple G ‘Girls Get Going in Tennis, in Football, and at the YMCA’ should be developed and implemented in an effort to arrest the decline in girls’ participation in sport, physical activity and physical education.

The Triple G program aims to develop, implement and evaluate a program to promote participation in physical activity by girls in rural and regional schools and communities. The impact of the Triple G program on the mental and physical wellbeing of the girls will also be evaluated. The program specifically aims to create school and community linkages through the introduction of tennis coaches, football coaches, and YMCA instructors into the physical education class to team teach with physical education staff during the 2011 school year. As part of the school-based program, Year 7 – 9 girls will participate in a YMCA unit and one of tennis or football during their physical education classes (6 sessions x 100mins each). Each unit is then followed by an eight week afterschool program at the local tennis or football club, or YMCA centre.

Gentrification and cosmopolitan leisure in inner-urban Melbourne, Australia, 1960s-1970s

Studies of gentrification in Australia have typically analysed the phenomenon through the lens of housing and residential change. This article explores how non-residential factors, including the concept of and the everyday practices associated with cosmopolitanism, offer an opportunity to analyse leisure specific to gentrification in Melbourne in the 1960s and 1970s. The article particularly explores leisure based on food and drink cultures located in restaurants, cafés and pubs. Adopting a discursive interdisciplinary approach to studies of the urban past, the article seeks to enhance our historical understanding of the interplay between gentrification and cosmopolitan leisure at a specific place and time in history, by exploring how people perceived themselves and their lifestyles in the midst of urban change.

Short term aerobic exercise training in young males does not alter sensitivity to a central serotonin agonist

An increase in the concentration of serotonin in the brain has been shown to cause fatigue during exercise in humans and experimental animals. This type of fatigue is referred to as central fatigue and is likely to be mediated by the concentration of serotonin as well as serotonin receptor sensitivity. Serotonin (5-HT) receptor antagonism in humans and experimental animals has been shown to improve endurance performance. A previous report has shown decreased receptor sensitivity in athletes compared to sedentary controls. It is unclear whether this is due to a training adaptation or if individuals are predisposed to enhanced athletic performance due to their inherent decreased receptor sensitivity. The present study investigated changes in 5-HT receptor sensitivity in response to aerobic exercise. Subjects completed 3 × 30 min of stationary cycling at 70% of their peak aerobic power (V̇O2,peak) for 9 weeks. Serotonin receptor sensitivity was assessed indirectly by measuring the neuroendocrine response following administration of a serotonin agonist (buspirone hydrochloride). The neuroendocrine response following administration of a placebo was also investigated in a blind crossover design. A group of sedentary control subjects was also recruited to control for seasonal variations in central receptor sensitivity. The training caused a significant increase in V̇O2,peak (3.1 ± 0.16 to 3.6 ± 0.15 l min−1, P < 0.05) and endurance capacity (93 ± 8 to 168 ± 11 min, P < 0.05), but there was no change (P > 0.05) in the neuroendocrine response in the presence of a serotonin agonist. However, one-quarter of the subjects in the training group demonstrated decreases in receptor sensitivity. These results suggest that despite increases in V̇O2,peak and endurance performance, there was no measurable change in 5-HT receptor sensitivity in the presence of a serotonin agonist. In addition, it is possible that changes in receptor sensitivity may take longer to occur, that the training stimulus used in the present investigation was inadequate and/or that changes occurred in receptor subtypes that were not probed by the agonist used in the present investigation.

Predictive validity and classification accuracy of ActiGraph energy expenditure equations and cut-points in young children

Objectives
Evaluate the predictive validity of ActiGraph energy expenditure equations and the classification accuracy of physical activity intensity cut-points in preschoolers.

Methods
Forty children aged 4–6 years (5.3±1.0 years) completed a ~150-min room calorimeter protocol involving age-appropriate sedentary, light and moderate-to vigorous-intensity physical activities. Children wore an ActiGraph GT3X on the right mid-axillary line of the hip. Energy expenditure measured by room calorimetry and physical activity intensity classified using direct observation were the criterion methods. Energy expenditure was predicted using Pate and Puyau equations. Physical activity intensity was classified using Evenson, Sirard, Van Cauwenberghe, Pate, Puyau, and Reilly, ActiGraph cut-points.

Results
The Pate equation significantly overestimated VO2 during sedentary behaviors, light physical activities and total VO2 (P<0.001). No difference was found between measured and predicted VO2 during moderate-to vigorous-intensity physical activities (P = 0.072). The Puyau equation significantly underestimated activity energy expenditure during moderate-to vigorous-intensity physical activities, light-intensity physical activities and total activity energy expenditure (P<0.0125). However, no overestimation of activity energy expenditure during sedentary behavior was found. The Evenson cut-point demonstrated significantly higher accuracy for classifying sedentary behaviors and light-intensity physical activities than others. Classification accuracy for moderate-to vigorous-intensity physical activities was significantly higher for Pate than others.

Conclusion
Available ActiGraph equations do not provide accurate estimates of energy expenditure across physical activity intensities in preschoolers. Cut-points of ≤25counts⋅15 s−1 and ≥420 counts⋅15 s−1 for classifying sedentary behaviors and moderate-to vigorous-intensity physical activities, respectively, are recommended.

Investigating the media power of a population health monitoring survey: case study of the NSW Schools Physical Activity and Nutrition Survey (SPANS)

Objective
To examine the extent and nature of news coverage of a government-funded population monitoring survey of children and the potential implications of this coverage for public health advocacy.

Methods
Case study of the NSW Schools Physical Activity and Nutrition Survey (SPANS), a population monitoring survey of school-aged children's weight and weight-related behaviours, conducted in 1997, 2004 and 2010. Printed news items from all Australian newspapers between January 1997 and December 2011 mentioning the survey findings were identified from the Factiva database and a descriptive analysis of the content conducted.

Results
Overall, 144 news items were identified. The news angles focused mainly on physical activity/sedentary behaviour; overweight/obesity and nutrition; however these angles changed between 1997 and 2011, with angles focused on physical activity/sedentary behaviour increasing, compared with overweight/obesity and nutrition angles (p=0.001). Responsibility for obesity and weight-related behaviours was most frequently assigned to parents and food marketing, and the most common solutions were policy strategies and parental/child education and support.

Conclusions
Population health surveys are newsworthy and when coupled with strategic dissemination, media can contribute to communicating health issues and interpreting findings in ways that are relevant for consumers, policy makers and stakeholders.

Implications
This case study emphasises the news value of government-funded population surveys, while providing a cautionary note about media focus on individual studies rather than a larger body of research evidence.

Health, behavioral, cognitive, and social correlates of breakfast skipping among women living in socioeconomically disadvantaged neighborhoods

Breakfast skipping is a potentially modifiable behavior that has negative effects on health and is socioeconomically patterned. This study aimed to examine the intrapersonal (health, behavioral, and cognitive) and social factors associated with breakfast skipping. Nonpregnant women (n = 4123) aged 18-45 y from socioeconomically disadvantaged neighborhoods throughout Victoria, Australia, completed a postal questionnaire. Sociodemographic characteristics, diet, physical activity, sedentary behaviors, and cognitive and social factors were assessed by self-report. Breakfast skipping was defined in 2 ways: 1) "rarely/never" eating breakfast (n = 498) and 2) eating breakfast ≤2 d/wk (includes those who rarely/never ate breakfast; n = 865). Poisson regression was used to calculate prevalence ratios and linear trends, adjusting for covariates. The P values for linear trends are reported below. Compared with breakfast consumers, women who reported rarely/never eating breakfast tended to have poorer self-rated health (P-trend &lt; 0.001), be current smokers (P-trend &lt; 0.001), pay less attention to health (P-trend &lt; 0.001), not prioritize their own healthy eating when busy looking after their family (P-trend &lt; 0.001), have less nutrition knowledge (P-trend &lt; 0.001), and a lower proportion were trying to control their weight (P-trend &lt; 0.020). When breakfast skipping was defined as eating breakfast ≤2 d/wk, additional associations were found for having lower leisure-time physical activity (P-trend = 0.012) and less self-efficacy for eating a healthy diet (P-trend &lt; 0.043). In conclusion, a range of intrapersonal and social factors were significantly associated with breakfast skipping among women living in socioeconomically disadvantaged areas. Acknowledging the cross-sectional design and need for causal confirmation, programs that aim to promote breakfast consumption in this population group should consider targeting family-related barriers to healthy eating and nutrition knowledge.