Physical Activity and Behavioural Epidemiology

Associate Professor David Dunstan
Head, Physical Activity Laboratory
NHMRC Senior Research Fellow
david.dunstan@bakeridi.edu.au
Phone: +61 3 8532 1873

Professor Neville Owen
Program Head: Behavioural and Generational Change
Head, Behavioural Epidemiology Laboratory
NHMRC Senior Principal Research Fellow
neville.owen@bakeridi.edu.au
Phone: +61 3 8532 1874

For media enquiries, please contact:
christina.hickie@bakeridi.edu.au
Phone: +61 3 8532 1129

The Physical Activity and Behavioural Epidemiology laboratories are concerned with the primary prevention of chronic diseases, specifically diabetes, heart disease and cancer. Our research deals with the health consequences of physical inactivity and sedentary behaviours; the measurement and analysis of environmental, social and personal-level determinants of behavioral risk factors (television viewing, sitting in automobiles, desk- and screen-bound work) and lack of physical activity; and, gathering and interpreting evidence from trials of broad-reaching interventions. The aim is to better understand how variations in behaviour can influence health outcomes and to identify the factors that can influence behavioural change.

The ultimate goal of our combined program is to contribute unique insights relevant to public health policy. We aim to identify environmental and social innovations that can increase physical activity and reduce sitting time.

The two laboratories are building comprehensive scientific links between epidemiological evidence; clinical/experimental investigations; behavioural intervention trials on changing sitting time in real-world settings; and large-scale population studies of environment/behaviour relationships in key target settings such as workplaces and more recently, schools. This integration aims to provide much-needed evidence to inform new policy directions in public health in order to reduce Australia's disease burden from excessive sedentary time and physical inactivity.

Research Focus

The integrated program of studies on physical activity, sedentary behaviour and health conducted by the Physical Activity and Behavioural Epidemiology laboratories includes:

  • Laboratory-based investigations of behaviour-biomarker relationships, dose-response and mechanisms
  • Cross-sectional and prospective epidemiologic observational studies
  • Measurement development studies using state-of-the-art accelerometer and inclinometer devices
  • Studies on the multiple levels of influence on physical activity and sedentary behaviour, focused on understanding environmental determinants
  • Field-based intervention trials on the feasibility and outcomes of changing physical activity and sedentary behaviour
  • The ongoing refinement of conceptual models to integrate the evidence and explain multiple levels of influence on physical activity and sedentary behaviour
  • Addressing research-translation implications
  • Informing clinical practice and public health policy.

Program Support

Centre of Research Excellence on Sitting Time and Chronic Disease Prevention - Mechanisms, Measurement and Interventions

Group leaders: Professor Neville Owen with Professor Jo Salmon, Professor Stewart Trost, Professor David Dunstan, Professor Elizabeth Eakin, Dr Genevieve Healy, Professor Bronwyn Kingwell, Professor Gavin Lambert and Associate Professor Anna Timperio

The overall aims of the CRE are to: 1) generate new knowledge on sitting time and chronic disease risk, focused on measurement, mechanisms and interventions; 2) translate research outcomes to inform public health guidelines, policy and practice for chronic disease prevention; 3) build inter-disciplinary research capacities among early and mid-career researchers; 4) extend and enhance national and international research collaborations.

Together with our collaborators from the University of Queensland and Deakin University, we have established a multidisciplinary research team that is focused on the prevention of major chronic diseases, particularly cardio-metabolic diseases: type 2 diabetes, cardiovascular disease and breast and colon cancer. Our expertise covers metabolic and vascular physiology, human neuroscience, exercise science, public health, epidemiology, psychology and human development. We conduct systematic laboratory studies to identify how variations in active and sedentary time influence mechanisms leading to increased chronic disease risk. Key emphases are to understand the determinants of behaviour change and maintenance, which we pursue through field-based intervention trials in real-world settings, and to address the translation of that knowledge into effective approaches to disease prevention. A major focus of our research is on identifying effective primary prevention approaches that can be delivered on a large scale through evidence-based programs that have been developed through systematic randomised controlled trials; and building a knowledge base that can broadly inform population health policy and practice.

The CRE is generously supported by NHMRC

Program Grant: Sitting less and moving more: Population health research to understand and influence sedentary behaviour

Group leaders: Professor Neville Owen with Professor Adrian Bauman (University of Sydney) and Professor Wendy Brown (University of Queensland)

The overall goal of this program is to carry out research that will inform the hypothesis that the population should sit less, as well as move more. This program of research focuses explicitly on understanding and influencing sedentary behaviour and its health sequelae. This involves measuring sitting time (in different contexts, including sitting for transport, at work, at home and in leisure time) and determining the increases in physical activity (LIPA or MVPA) that would be required to achieve health outcomes, as well as how best to go about achieving such changes. It represents a paradigm shift in thinking about the balance of sedentary behaviour and activity in all aspects of daily life.

The program includes six research areas:
Area 1. Measurement and surveillance
Aim - To refine and develop self-report and objective measures of sedentary behaviour and physical activity that are relevant to the major domains of daily life
Area 2. Determinants
Aim - To identify domain-specific determinants (demographic, psychological, social and environmental) of sedentary time and physical activity in adults
Area 3. Primary prevention
Aim - To identify novel relationships between sitting time, physical activity, and the primary prevention of non-communicable disease
Area 4. Secondary and tertiary prevention
Aim - To increase the evidence base on the changes in sedentary behaviour and physical activity that are needed to bring about better health outcomes (through controlled intervention trials)
Area 5. Mass-reach and population interventions
Aim - To increase the evidence base for mass-reach intervention approaches suitable for population strategies to decrease sitting time and increase physical activity in different domains
Area 6. Public health research capacity building and informing policy development
Aim - To contribute to the development of evidence-based public policy strategies, internationally, nationally and locally, and to promote research capacity building.

The Program Grant is generously supported by NHMRC

Research Projects

Reducing prolonged sitting in office workers: the Stand Up Victoria study

Group leaders: Associate Professor David Dunstan with Dr Genevieve Healy and Dr Glen Wiesner

The aim of the Stand Up Victoria study is to determine the effectiveness of an intervention program aimed at reducing prolonged workplace sitting time in office workers. It also is evaluating the effect of the intervention on markers of diabetes and heart health. An important and novel aspect of this study is the use of devices to objectively measure sitting time and physical activity levels rather than the self-report approach used in previous studies.

Baker IDI Heart and Diabetes Institute, in collaboration with researchers from the University of Queensland, the University of Melbourne and Deakin University, are conducting this 3-year trial within the Australian Government Department of Human Services (DHS). It aims to recruit 320 DHS employees from a number of offices around Victoria. Physical activity levels and sitting time will be measured at three time-points over 12 months. In addition, various markers of health and disease such as blood pressure, blood glucose, insulin and lipids, and body composition will be assessed.

Watch the VicHealth Creating Healthy Workplaces - Reducing Prolonged Sitting in the Workplace video:

Short version (3:09 minutes)  

Extended version (5:28 minutes)

Stand Up Victoria is generously supported by NHMRC and VicHealth

- Logo - VicHealth

Breaking up prolonged sitting with walking and brief simple resistance activities for the management of type 2 diabetes (T2D): The REsistance and WAlking in Reducing Diabetes Study

Group leaders: Associate Professor David Dunstan with Paddy Dempsey (PhD Student), Professor Bronwyn Kingwell and Professor Neville Owen

While engagement in both aerobic and resistance exercise is a cornerstone in the management of T2D, many patients are often deconditioned, overweight/obese, or unable or insufficiently motivated to meet prescribed exercise recommendations. Furthermore, observational data suggests that those with T2D spend over 9 hr/day sitting - a lifestyle behaviour which is likely to predispose them to a greater risk of micro/macrovascular complications. Thus, there is a need for practical and innovative lifestyle strategies that can optimise daily metabolic function and ultimately reduce the risk of such complications. Our recent observational and experimental findings have demonstrated that the introduction of brief, light-intensity activity breaks during prolonged sitting time can lead to beneficial impacts on blood glucose control, insulin sensitivity, blood pressure, and blood viscosity parameters in individuals deemed at-risk of developing T2D. While these findings are promising, experimental studies are yet to establish the clinical relevance of breaking up sitting on glycaemic control in adults with T2D.

The proposed study represents an important ‘next step' in gaining a better understanding of the extent to which novel, convenient and practical modes of activity (potentially incorporated into places where sitting is highly prevalent - such as the workplace or in the home), can help minimise the harmful effects of prolonged sitting in patients with T2D. Specifically, it will investigate the impact of breaks in prolonged sitting using brief (3 minute) bouts of walking or simple resistance activities on postprandial (post-meal) blood glucose in patients with T2D. Additionally, through collaborations with other laboratories within Baker IDI, we will assess candidate mechanisms to better understand the broader biological implications of such behaviours. The results of this study have the potential to provide more detailed and potentially prescriptive information to help shape clinical and public health approaches for the management of T2D.

Aim: To conduct a randomised crossover trial in adults with T2D to investigate the acute (1-day) effects of a single bout of prolonged sitting on postprandial blood glucose with and without intermittent bouts of light-intensity walking or simple resistance activities.
Hypothesis 1: Changes in postprandial glucose resulting from a single bout of prolonged sitting will be attenuated by incorporating brief intermittent bouts of physical activity in the form of either light-intensity walking bouts or simple resistance activities.
Hypothesis 2: Brief intermittent bouts of physical activity will reduce glycaemic variability and hyperglycaemic episodes (>10 mmol/L) over 22 hours compared to a bout of prolonged sitting.
Exploratory Hypothesis: Modulation of postprandial glucose resulting from activity bouts will be mediated by both changes in insulin secretion/sensitivity and glucagon. Given the important role of the sympathetic nervous system and incretins (which potentiate post-meal insulin release in a glucose dependant manner) in modulating these factors, these mechanisms will be explored.

Reducing sitting time in the school classroom - The Make a Stand Kids! (MASK) pilot intervention

Group leaders: Associate Professor David Dunstan and Professor Jo Salmon (Deakin University)

Among Australian children, the precursors of future lifestyle diseases are a major public health issue - the development of type 2 diabetes, cardiovascular disease and some cancers has origins in childhood. Numerous environmental changes have resulted in children not only becoming less physically active, but also spending unnecessarily long periods of time sitting - particularly in the school environment. There is growing evidence that too much sitting, in addition to too little physical activity, can be bad for children's health. The MASK pilot project aims to examine the feasibility and potential benefits of changing the traditional classroom environment and lesson delivery. The study examines the effects of sit/stand workstations on children's sitting time, cardiovascular health indices, and learning and memory outcomes. Such initiatives could have a substantial and sustained impact on lesson delivery and the classroom environment in Australian classes in the future and important positive benefits to children's cardio-metabolic health and learning.

Baker IDI Heart and Diabetes Institute, in collaboration with researchers from Deakin University, are conducting this trial within a Primary school in Melbourne involving 40-50 children from Year 6 (aged approximately 11 and 12 years). It is expected that the pilot findings will assist in helping to inform the development of a larger scale trial involving several schools across metropolitan Melbourne.

MASK is generously supported by a Vanguard Grant from the Heart Foundation Research Program

Taking a break for brain health: interacting effects of exercise bouts with breaks in sitting time on cognitive and cerebrovascular function in overweight adults

Group leaders: Associate Professor David Dunstan with Professor Daniel Green (University of Western Australia), Dr Kathryn Ellis (University of Melbourne) and Professor Ester Cerin (Deakin University)

Maintaining optimal cognitive function through mid- and late-life is vital for independence, quality of life and productivity at work. Disease-modifying pharmacological approaches for the prevention of cognitive decline currently do not exist; however, there is substantial evidence supporting the use of regular physical activity or exercise training as an effective preventive or therapeutic strategy. Whilst a single bout of exercise can enhance several aspects of cognition in adults, it is not known whether such improvements persist in the face of prolonged sitting periods, characteristic of contemporary living. The proposed research uniquely combines metabolic and vascular physiology and neuropsychological expertise in the first experimental trial to investigate the impacts of interrupting prolonged sitting on cognitive functioning in overweight adults. This study will determine whether combining moderate-intensity exercise with short light-intensity breaks from prolonged sitting improves cognitive and cerebrovascular function. It will provide crucial evidence that can inform recommendations on realistic lifestyle changes that could improve cognitive function.

Taking a break for brain health is generously supported by NHMRC 

Sedentary behaviour and cancer

Group leaders: Professor Neville Owen with Dr Brigid Lynch and Associate Professor David Dunstan

Sedentary behaviour has been proposed as an independent risk factor for cancer. Biologically plausible mechanisms exist, however few studies have examined sedentary behaviour in a cancer context. We are developing a program of research in this emerging field of enquiry. Opportunities exist for epidemiological studies examining associations of sedentary behaviour with cancer risk and with intermediary endpoints in large, prospective cohort studies. We also wish to better understand the underlying biological mechanisms by which sedentary behaviour affects cancer risk. We plan to examine the effect of acute bouts of prolonged sitting on cancer biomarkers such as endogenous sex hormones and adipokines in laboratory-based experiments. Finally, we are interested in rigorously characterising the sedentary behaviour of cancer survivors, and investigating how it contributes to health outcomes in this population.

Physical activity and the environment: domain-specific examination

Group leaders: Professor Neville Owen with Dr Takemi Sugiyama, Dr Brigid Lynch and Dr Javad Koohsari

In examining environmental attributes associated with physical activity, studies have focused on neighbourhood environments. A number of instruments have been developed to capture residential environmental factors that may be relevant to physical activity participation. However, physical activity has been measured without specifying where it occurs. In order to accurately assess the role of environments, it is important to examine specific behaviours (eg, walking, cycling, sitting) taking place in a specific context. At Baker IDI, we use this principle to examine how environments in different domains influence specific health behaviours.

- Physical Activity - Domain-specific examination

Using data collected from AusDiab3 (the third round of the Australian Diabetes, Obesity and Lifestyle study), we are examining the influence of walking (for transport and for recreation) in one's neighbourhood and car use for transport, and examine if they are related to objectively-determined neighbourhood environmental attributes (using Geographic Information Systems).

Identifying Health Consequences and the Social and Environmental Determinants of Physical Activity and Sedentary Behaviour

Group leaders: Associate Professor David Dunstan and Professor Neville Owen with Nyssa Hadgraft (PhD Student) and Bethany Howard (PhD Student)

Within an established program of observational-study research that uses large, multi-variable cross-sectional and prospective data sets, we conduct two main threads of investigation designed to inform population-based approaches to the primary prevention of cardiovascular disease and diabetes:
1) What are the unique relationships of physical activity and sedentary behaviour with cardio-metabolic risk biomarkers and with morbidity and mortality outcomes?
2) Identifying the environmental and social determinants of physical activity and sedentary behaviour - what needs to be changed in order to increase physical activity and reduce prolonged sitting time?

Data sets used for these studies include:

  • AusDiab (the Australian Diabetes, Obesity and Lifestyle study), with data collected at three time points (AusDiab 1: 1999-2000; AusDiab 2: 2004-2005; and AusDiab 3: 2011-2012)
  • NHANES (the National Health and Nutrition Examination Survey - a population-representative surveillance study of US civilians)
  • PLACE (Physical Activity in Localities and Community Environments - a study with two observation points four years apart that includes objective measures of environmental attributes derived from Geographic Information Systems data sets)
  • IPEN (International Physical Activity and the Environment Network study - a US National Cancer Institute funded study gathering accelerometer, survey and geographic information system data from 11 countries)

In identifying unique health consequences of physical activity and sedentary behaviour, in our work with AusDiab - for example - we are using device-derived measures to examine relationships with cardio-metabolic risk biomarkers of the patterns and accumulation of time spent sitting, standing, stepping and in light-intensity and moderate-to-vigorous intensity activity. AusDiab 3 is the first large population based study that has highly precise measures of sitting time (ActivPal inclinometer) together with an array of biological measures, including an oral glucose tolerance test. Compared to accelerometer-derived data, ActivPal data provide a much more precise indicator of sitting time, as it is able to measure posture and is thus an excellent tool to identify health consequences of too little physical activity and too much sitting.
In understanding the social and environmental determinants of physical activity and sedentary behaviour, we are working with data from AusDiab and the PLACE and IPEN studies to identify unique behavioural determinants with the potential to be addressed through large-scale policy initiatives to reduce chronic disease risk. For example, we have initially shown significant associations of objective and perceived indices of ‘neighbourhood walkability' with levels of physical activity and sedentary behaviour; ongoing studies are examining the influence of specific environmental attributes (including walking routes and local destinations).

The AusDiab project is generously supported by NHMRC

Download a 2 page Physical Acitvity lab profile here
Download a 2 page Behavioural Epidemiology lab profile here

Download a Physical Activity publications list here
Download a Behavioural Epidemiology publications list here