Current guidelines suggest that physical activity must be performed at a moderate-to-vigorous intensity (MVPA) and accumulated in bouts of at least 10 consecutive minutes to elicit improvement in cardiorespiratory fitness (CRF). In the first study we sought to determine whether the duration and intensity of objectively measured incidental physical activity (IPA; activity performed below the designated threshold) was associated with CRF in abdominally obese, inactive men (n=43) and women (n=92). Secondary analyses examined the associations between light physical activity (LPA), sporadic moderate physical activity (MPA; accumulated in <10 minute bouts), and CRF. Both duration and intensity of IPA were positively associated with CRF among inactive, abdominally obese adults. Sporadic MPA, but not LPA, was an independent predictor of CRF. Whereas some observations suggest that sedentary behaviour (SED) is negatively associated with health outcomes, other evidence fails to support this notion. The primary aim of the second study was to clarify the relationships between SED, LPA, and MVPA with 2-hour glucose and insulin resistance in inactive adults (43 men, 92 women) with abdominal obesity. Secondary analyses examined the association between SED, LPA, MVPA and other common cardiometabolic risk factors. Neither SED nor the physical activity variables were associated with 2-hour glucose or insulin resistance. SED was not associated with any cardiometabolic risk factor; with the exception of blood pressure, LPA was not associated with any cardiometabolic risk factor; and MVPA was independently associated with total cholesterol and triglycerides. Whether IPA is associated with abdominal obesity is unknown. The purpose of study three was to determine the association between IPA and abdominal adipose tissue depots (visceral adipose tissue and subcutaneous adipose tissue) in inactive men (n=42) and women (n=84). Secondary analyses examined the associations between SED, sleep duration, and caloric intake with abdominal obesity. IPA was not associated with any measure of abdominal obesity, nor was LPA. After control for age and sex, MPA was negatively associated with visceral adipose tissue. SED and sleep duration were not associated with abdominal obesity. Caloric intake was not associated with abdominal obesity after control for age and sex. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2011-05-17 13:33:52.518

The overall objectives of this thesis were to (1) describe the sedentary behaviour levels of young people; (2) examine the impact of sedentary behaviour on obesity and other physical health outcomes among young people; and (3) examine the influence that individual, social, and environmental factors have on the sedentary behaviour of young people. Six manuscripts addressed these objectives. Manuscript one assessed the proportion of 0- to 4-year-olds meeting the new Canadian Sedentary Behaviour Guidelines for the Early Years in a sample of pre-school children. More than half of the children exceeded the guidelines and the majority of their parents believed that their child did not engage in excessive screen time. Manuscript two examined the association between types, overall volume, and patterns of sedentary behaviour with cardio-metabolic risk factors in a sample of children and adolescents. Television viewing predicted cardio-metabolic risk factors independent of moderate-to vigorous-intensity physical activity. No associations were observed for the other sedentary behaviour components. Manuscript three examined whether the relationship between television viewing and obesity in a sample of youth was mediated by dietary habits. While a positive association was observed between television viewing and body mass index, it was not explained by dietary habits. Manuscript four examined urban-rural differences in screen time in two samples of youth. Rural American youth were the most likely to be excessive television users and the least likely to be excessive computer users. Conversely, urban Canadian youth were the least likely to be excessive television users and the most likely to be excessive computer users. Manuscript five examined the association between neighbourhood disorder and screen time in a sample of youth. Participants in neighbourhoods with high social and high physical disorder were the most likely to engage in excessive screen time. Manuscript six examined associations between factors within the home setting and screen time among a sample of pre-school children. Several factors collectively explained 64.1% of the variance in television viewing including parental cognitive factors, which explained 41.0%. The findings of this thesis have important implications for future public health interventions and initiatives as well as future research in this area. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2012-06-12 08:52:19.91

Background: Sedentary behaviour is waking activity in a seated or reclined position that involves little energy expenditure. It is gaining attention as an important cardiometabolic risk factor, independent of physical activity. Studies assessing the relationship between sedentary behaviour and cardiometabolic risk have not accounted for sleep duration as a potential covariate, although there is evidence that sleep duration may be related to both sedentary behaviour and cardiometabolic risk. Objectives: To examine the associations between sleep duration and sedentary behaviour in adults, and determine if sedentary behaviour is related to the metabolic syndrome (MetS) after controlling for sleep duration. Methods: This cross-sectional study used data from the 2003-2006 National Health and Nutrition Examination Survey, a representative sample of Americans. There were 1371 adults over the age of 20 that were studied. Average daily sedentary time and sleep duration were determined via 7-day accelerometry. Screen time (television, computer) was determined via questionnaire. The MetS was determined using standard criteria. Analysis of variance was used to examine relationships among sedentary time and screen time with sleep duration. Multiple logistic regression was used to examine associations between total sedentary time, screen time, and sleep duration with the MetS after controlling for several covariates. Results: Sedentary time and screen time did not vary across sleep duration quartiles (p=0.08 and p=0.87, respectively), and therefore were unrelated to sleep duration. The relative odds of the MetS was significantly higher in participants in the highest quartile of sedentary time than in participants in the lowest quartile (OR=1.60, 95% CI:1.05-2.45). The relative odds of the MetS was higher in participants in the highest screen time tertile than in participants in the lowest tertile (OR =1.67, 95% CI:1.13-2.48). Short sleep duration was not independently related to the MetS, but was borderline related to waist circumference (OR=1.25, 95% CI:0.85-1.84). Conclusion: Highly sedentary individuals and individuals with a high screen time are more likely to have the MetS, independent of sleep duration. Future studies in this area would benefit from using more advanced objective measures of sedentary behaviour and sleep duration and a prospective study design. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2013-10-29 15:40:55.494

Previous theory-driven research studies in the activity area examining descriptive norms (e.g., Priebe & Spink, 2011, 2012) have demonstrated that these perceptions about others’ behaviour can influence individual behaviour. Although the results of these studies are informative, many questions still remain. The studies comprising this thesis add to the extant literature by improving upon methodological limitations of past work, extending the examination of the effects of norms on activity to include both injunctive norms (i.e., perceptions about others’ approval) and combined norms (aligned and misaligned), examining other activity-related cognitions (self-efficacy) and behaviour (sedentary), as well as examining characteristics of the norm reference group. Three independent experimental studies were conducted. Study 1 examined the effects of a descriptive norm message on muscular endurance and task self-efficacy in Pilates participants. Results revealed greater endurance and higher task self-efficacy among participants in the descriptive norm information condition as compared to control group participants. Study 2 compared four information conditions: injunctive, aligned descriptive and injunctive, misaligned descriptive and injunctive, and control with respect to their influence on muscular endurance and efficacy in a student population. Individuals receiving the aligned norms had the longest post-condition muscular endurance and greater task efficacy than all other conditions. No differences emerged between the injunctive, misaligned, and control conditions. Study 3, an online experimental field study, examined the effects of descriptive norms on both light activity and sedentary behaviour in an office setting. Study 3 also examined the effects of norms when the reference group differed in personal or contextual similarity. No differences emerged between participants receiving information about groups that varied in similarity. However, after receiving an email with descriptive norm information about co-workers’ behaviour, light activity increased and sitting behaviour decreased within the office setting across all conditions. Results from these three studies suggest the following: (1) aligned norms seem to be more effective than misaligned, (2) standalone injunctive norms might not be salient in the activity setting, (3) descriptive norms can impact objective activity behaviour, self-report light activity and sedentary behaviour, and (4) descriptive norms also may inform related cognitive constructs such as task self-efficacy.

The increasing evidence of associations between physical activity, sedentary behaviour, sleep duration and diet and both immediate and long term health implications is of public health concern. There is a need to further our understanding of the patterns of these behaviours and how they affect poor health indicators individually and simultaneously. This thesis aims to advance the current literature by investigating associations between multiple lifestyle behaviours and indicators for poor health and identifying patterns of physical activity, sedentary behaviour, sleep duration and dietary intake. Anthropometric measurements and bioelectrical impedance analysis were collected from 72 UK adults. These participants were asked to wear an ActiGraph GT1M accelerometer to objectively measure their physical activity and sedentary behaviour across 7 consecutive days. Over these 7 days, participants also completed a self-report daily sleep diary and a food frequency questionnaire. Participants were asked to complete these measurements at 4 different time points across the year in order to capture these behaviours over each season; 46 participants completed all 4 seasons. Using the data collected from the 72 participants who completed at least 1 season, regression analyses were conducted to identify associations between lifestyle behaviours and indicators for poor health. Repeated measures ANOVAs were conducted on data from 52 participants who provided the full 7 days of data during their initial measurement period to assess day of the week variations in physical activity, sedentary behaviour and sleep patterns. Repeated measures ANOVAs were also conducted on physical activity, sedentary behaviour, sleep and dietary intake data provided by the 46 participants who provided 4 seasons of data to assess seasonal variation. This thesis demonstrated that in a sample of relatively active, UK adults, time spent in moderate-vigorous physical activity and sedentary behaviour had a negative association with BMI and body fat percentage, increased time spent in moderate-vigorous physical activity was also associated with decreases in waist circumference. Light intensity physical activity had a positive association with BMI, body fat percentage and diastolic blood pressure. There were significant day of the week variations in light intensity physical activity, sedentary behaviour and time spent in bed, with light intensity physical activity and time in bed being significantly higher on a Sunday, whilst sedentary behaviour was significantly lower on a Sunday in this sample of UK adults. In addition to day of the week variations, there were seasonal variations in light intensity physical activity, sedentary behaviour and time spent in bed and sleep durations (weekdays only). Over the winter months, light intensity physical activity was significantly lower, whilst sedentary behaviour, time in bed and total sleep time was significantly higher. No seasonal variations in time spent in moderate-vigorous intensity physical activity or diet were observed in the present sample. This thesis demonstrates that lifestyle behaviours that have been found to affect health do vary over the week and across different seasons. This research has implications for surveillance studies which estimate these behaviours at one time point throughout the year, and also for interventions aimed at improving these behaviours which are implemented at just one time period of the year. Strategies for overcoming barriers to PA under unfavourable environmental conditions will be needed for this to be achieved, in addition to interventions reducing SB, even in the winter months.

There is currently a dearth of information suitable for the development of evidence-based physical activity and screen time guidelines for children and youth. The overarching purpose of this thesis was to generate findings that could be used to inform public health recommendations for physical activity and screen time. A series of six manuscripts were completed to explore the relationship between physical activity, sedentary behaviour, and health in youth. The first manuscript examined the dose-response relation between objectively measured total and moderate-to-vigorous physical activity with blood pressure and hypertension. Participating in 30 and 60 minutes of moderate-to-vigorous physical activity per day decreased the odds of hypertension in youth by 50% and 63%, respectively. The second manuscript explored the influence of intensity of physical activity and incidental movement on total and trunk adiposity. Moderate-to-vigorous intensity physical activity was found to predict total and trunk adiposity beyond other intensities and incidental movement. The third manuscript sought to determine whether or not physical activity accrued in bouts was more beneficial than total physical activity with relation to being overweight. The inclusion of short and medium-to-long bouts of physical activity decreased the odds of overweight above and beyond total physical activity level. The fourth manuscript included a detailed examination of the relation between physical activity and screen time by considering different forms of physical activity, different physical activity environments, and various screen time behaviours. By and large, physical activity and screen time were not related. The fifth manuscript determined the proportion of Canadian youth meeting screen time guidelines. Only 18% of girls and 14% of boys in grades 6 to 10 met screen time guidelines of no more than 2 hours per day. The final manuscript examined the relationship between screen time and metabolic syndrome. A dose-response relation was observed between screen time and metabolic syndrome independent of physical activity level. It is hoped that the findings from this thesis will provide useful information that will be considered in developing and modifying physical activity and screen time recommendations for the paediatric population. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2008-12-13 15:44:07.654

Background: Shift work is associated with increased risk of cardiovascular disease and cancer, where decreased melatonin has been proposed as an intermediate in the causal pathway. The influence of physical activity on melatonin has rarely been studied in an observational setting, and it may be important in mediating the effects of shift work. We aimed to assess the influence of energy expended during physical activity of different intensities on melatonin among rotating shift nurses. We hypothesized that physical activity before the night shift would lessen the decrease in melatonin production that occurs with exposure to light at night. Methods: 123 female rotating shift nurses working at Kingston General Hospital were recruited over a one-year period. Physical activity and sedentary behaviours for each participant were recorded during both a day and a night shift using activity diaries, and analysis was restricted to activities between 3 p.m. and 7 a.m. Concentrations of urinary 6-sulfatoxymelatonin, a melatonin metabolite, in morning void urine samples were analyzed for each shift. Results: The average age of participants was 41 years, and 60% were overweight or obese (body mass index ≥ 25 kg/m2). An average of 6.9 and 5.2 hours of sleep were reported after the day shift and night shift, respectively. Sedentary behaviours such as standing and television watching accounted for over half of the total reported energy expenditure. During the day shift, energy expended in moderate and vigorous intensity physical activity between 3 p.m. and 7 a.m. was negatively associated with melatonin levels (p=0.024, R2 = 0.09). During the night shift, energy expended in sedentary behaviours was negatively associated with melatonin levels (p=0.008, R2 = 0.03). Conclusions: Physical activity energy expenditure explains only a small amount of melatonin variation, suggesting that other factors are influencing melatonin production, or that melatonin production is minimally effected by these patterns of physical activity. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2010-09-01 11:22:35.915

Objective data from national surveillance programmes show that, on average, individuals accumulate high amounts of sedentary time per day and only a small minority of adults achieve physical activity guidelines. One potential explanation for the failure of interventions to increase population levels of physical activity or decrease sedentary time is that research to date has been unable to identify the specific behavioural levers in specific contexts needed to change behaviour. Novel technology is emerging with the potential to elucidate these specific behavioural contexts and thus identify these specific behavioural levers. Therefore the aims of this four study thesis were to identify novel technologies capable of measuring the behavioural context, to evaluate and validate the most promising technology and to then pilot this technology to assess the behavioural context of older adults, shown by surveillance programmes to be the least physically active and most sedentary age group. Study one Purpose: To identify, via a systematic review, technologies which have been used or could be used to measure the location of physical activity or sedentary behaviour. Methods: Four electronic databases were searched using key terms built around behaviour, technology and location. To be eligible for inclusion papers were required to be published in English and describe a wearable or portable technology or device capable of measuring location. Searches were performed from the inception of the database up to 04/02/2015. Searches were also performed using three internet search engines. Specialised software was used to download search results and thus mitigate the potential pitfalls of changing search algorithms. Results: 188 research papers met the inclusion criteria. Global positioning systems were the most widely used location technology in the published research, followed by wearable cameras and Radio-frequency identification. Internet search engines identified 81 global positioning systems, 35 real-time locating systems and 21 wearable cameras. Conclusion: The addition of location information to existing measures of physical activity and sedentary behaviour will provide important behavioural information. Study Two Purpose: This study investigated the Actigraph proximity feature across three experiments. The aim of Experiment One was to assess the basic characteristics of the Actigraph RSSI signal across a range of straight line distances. Experiment Two aimed to assess the level of receiver device signal detection in a single room under unobstructed conditions, when various obstructions are introduced and the impacts these obstructions have on the intra and inter unit variability of the RSSI signal. Finally, Experiment Three aimed to assess signal contamination across multiple rooms (i.e. one beacon being detected in multiple rooms). Methods: Across all experiments, the receiver(s) collected data at 10 second epochs, the highest resolution possible. In Experiment One two devices, one receiver and one beacon, were placed opposite each other at 10cm increments for one minute at each distance. The RSSI-distance relationship was then visually assessed for linearity. In Experiment Two, a test room was demarcated into 0.5 x 0.5 m grids with receivers simultaneously placed in each demarcated grid. This process was then repeated under wood, metal and human obstruction conditions. Descriptive tallies were used to assess the signal detection achieved for each receiver from each beacon in each grid. Mean RSSI signal was calculated for each condition alongside intra and inter-unit standard deviation, coefficient of variation and standard error of the measurement. In Experiment Three, a test apartment was used with three beacons placed across two rooms. The researcher then completed simulated conditions for 10 minutes each across the two rooms. The percentage of epochs where a signal was detected from each of the three beacons across each test condition was then calculated. Results: In Experiment One, the relationship between RSSI and distance was found to be non-linear. In Experiment Two, high signal detection was achieved in all conditions; however, there was a large degree of intra and inter-unit variability in RSSI. In Experiment Three, there was a large degree of multi-room signal contamination. Conclusion: The Actigraph proximity feature can provide a binary indicator of room level location. Study Three Purpose: To use novel technology in three small feasibility trials to ascertain where the greatest utility can be demonstrated. Methods: Feasibility Trial One assessed the concurrent validity of electrical energy monitoring and wearable cameras as measures of television viewing. Feasibility Trial Two utilised indoor location monitoring to assess where older adult care home residents accumulate their sedentary time. Lastly, Feasibility Trial Three investigated the use of proximity sensors to quantify exposure to a height adjustable desk Results: Feasibility Trial One found that on average the television is switched on for 202 minutes per day but is visible in just 90 minutes of wearable camera images with a further 52 minutes where the participant is in their living room but the television is not visible in the image. Feasibility Trial Two found that residents were highly sedentary (sitting for an average of 720 minutes per day) and spent the majority of their time in their own rooms with more time spent in communal areas in the morning than in the afternoon. Feasibility Trial Three found a discrepancy between self-reported work hours and objectively measured office dwell time. Conclusion: The feasibility trials outlined in this study show the utility of objectively measuring context to provide more detailed and refined data. Study Four Purpose: To objectively measure the context of sedentary behaviour in the most sedentary age group, older adults. Methods: 26 residents and 13 staff were recruited from two care homes. Each participant wore an Actigraph GT9X on their non-dominant wrist and a LumoBack posture sensor on their lower back for one week. The Actigraph recorded proximity every 10 seconds and acceleration at 100 Hz. LumoBack data were provided as summaries per 5 minutes. Beacon Actigraphs were placed around each care home in the resident s rooms, communal areas and corridors. Proximity and posture data were combined in 5 minute epochs with descriptive analysis of average time spent sitting in each area produced. Acceleration data were summarised into 10 second epochs and combined with proximity data to show the average count per epoch in each area of the care home. Mann-Whitney tests were performed to test for differences between care homes. Results: No significant differences were found between Care Home One and Care Home Two in the amount of time spent sitting in communal areas of the care home (301 minutes per day and 39 minutes per day respectively, U=23, p=0.057) or in the amount of time residents spent sitting in their own room (215 minutes per day and 337 minutes per day in Care Home One and Two respectively, U=32, p=0.238). In both care homes, accelerometer measured average movement increases with the number of residents in the communal area. Conclusion: The Actigraph proximity system was able to quantify the context of sedentary behaviour in older adults. This enabled the identification of levers for behaviour change which can be used to reduce sedentary time in this group. Overall conclusion: There are a large number of technologies available with the potential to measure the context of physical activity or sedentary time. The Actigraph proximity feature is one such technology. This technology is able to provide a binary measure of proximity via the detection or non-detection of Bluetooth signal: however, the variability of the signal prohibits distance estimation. / The Actigraph proximity feature, in combination with a posture sensor, is able to elucidate the context of physical activity and sedentary time.

Physical inactivity and sedentary behaviour have been independently associated with a wide range of negative health indicators including obesity, poor cardio-metabolic health, and poor psychosocial health. The overarching objective of this research was to gain a better understanding as to why children are sedentary, and where we need to focus public health messages and interventions to reduce sedentary behaviour. Specifically, I aimed to provide insight on current awareness of sedentary behaviour guidelines; determine important correlates of total sedentary time (SED), and screen time (ST) in Canadian children; and understand correlates of SED and ST in a global context. The primary dataset used for this project was the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). Background work was completed to review current literature on knowledge and awareness of Canadian physical activity and sedentary behaviour guidelines (in all age groups), and to understand the representativeness of the ISCOLE dataset. In addition to the two background papers, this dissertation includes three manuscripts, all prepared for submission in scientific, peer-reviewed journals: 1. Manuscript 1: Canadian physical activity and screen time guidelines: do children know? 2. Manuscript 2: Correlates of objectively measured sedentary time and self-reported screen time in Canadian children 3. Manuscript 3: Correlates of total sedentary time and screen time in 9-11 year-old children around the world: The International Study of Childhood Obesity, Lifestyle and the Environment Overall, this work showed the majority of children around the world are accumulating large amounts of sedentary time, and exceeded current screen time guidelines. We found that the large majority of Canadian children are not aware of screen time guidelines; however, a greater proportion of children could identify physical activity guidelines. We also identified a number of correlates of SED, and ST in Canadian children, and in children around the world. The most common correlates included weight status, and access to electronics in the house. Taken together, this work suggests that public health messaging should focus on increasing awareness of screen time guidelines. While increasing awareness of the guidelines, messaging can be tailored to promoting healthy weight status, and reducing (or removing) children’s access to electronic devices in hopes of reducing overall time spent sedentary.

The purpose of this thesis was to determine the effectiveness of strategies to reduce sedentary behaviour (SB) and to communicate these strategies to healthy adults working in academic occupations using an educational video. Study One was a systematic review and meta-analysis of published literature on strategies to reduce SB in the home and workplace environments for healthy adults. Study Two was a single group pre-post study design to determine the effect of an educational video on viewers’ health beliefs related to reducing SB and daily sitting time. The information gained from these studies could be used to inform future interventions to reduce SB in the adult population. / Thesis / Master of Science Rehabilitation Science (MSc)