Global positioning system: a new opportunity in physical activity measurement

Accurate measurement of physical activity is a pre-requisite to monitor population physical activity levels and design effective interventions. Global Positioning System (GPS) technology offers potential to improve the measurement of physical activity. This paper 1) reviews the extant literature on the application of GPS to monitor human movement, with a particular emphasis on free-living physical activity, 2) discusses issues associated with GPS use, and 3) provides recommendations for future research. Overall findings show that GPS is a useful tool to augment our understanding of physical activity by providing the context (location) of the activity and used together with Geographical Information Systems can provide some insight into how people interact with the environment. However, no studies have shown that GPS alone is a reliable and valid measure of physical activity.

Development of a reliable measure of walking within and outside the local neighbourhood: RESIDE's neighborhood physical activity questionnarire.

Background: The RESIDential Environment project (RESIDE) is a longitudinal study evaluating the impact of a new residential design code on walking. Objective: To develop a reliable measure of walking – undertaken within and outside the neighborhood – and overall physical activity. Methods: A test–retest reliability study was undertaken (n = 82, mean age 39 years). The instrument was based on the International Physical Activity Questionnaire (IPAQ-short version) and Active Australia Survey. It measured usual frequency and duration of (1) recreational- and transport-related walking within and outside the neighborhood and (2) other vigorous and moderate physical activities. Results: Reliability of recall of whether participants had walked within (k = 0.84) and outside (0.73) the neighborhood was acceptable. Similarly, recall of frequency and duration of transport and recreational-related walking within the neighborhood was excellent (ICC ≥ 0.82), as was recall of transport-related walking trips outside the neighborhood (ICC ≥ 0.84). Reliability for duration of recreational walking outside the neighborhood was fair to good (ICC = 0.55). The reliability of indices of total physical activity based on MET min/week (ICC = 0.82) and MET min/week dichotomized to ‘sufficient’ physical activity for health (kappa = 0.67) were both acceptable. Conclusions:  The Neighborhood Physical Activity Questionnaire (NPAQ) is sufficiently reliable for studies examining environmental correlates of walking within the neighborhood.

Physical activity parenting measurement and research : challenges, explanations and solutions

Physical activity (PA) parenting research has proliferated over the past decade, with findings verifying the influential role that parents play in children's emerging PA behaviors. This knowledge, however, has not translated into effective family-based PA interventions. During a preconference workshop to the 2012 International Society for Behavioral Nutrition and Physical Activity annual meeting, a PA parenting workgroup met to: (1) Discuss challenges in PA parenting research that may limit its translation, (2) identify explanations or reasons for such challenges, and (3) recommend strategies for future research. Challenges discussed by the workgroup included a proliferation of disconnected and inconsistently measured constructs, a limited understanding of the dimensions of PA parenting, and a narrow conceptualization of hypothesized moderators of the relationship between PA parenting and child PA. Potential reasons for such challenges emphasized by the group included a disinclination to employ theory when developing measures and examining predictors and outcomes of PA parenting as well as a lack of agreed-upon measurement standards. Suggested solutions focused on the need to link PA parenting research with general parenting research, define and adopt rigorous standards of measurement, and identify new methods to assess PA parenting. As an initial step toward implementing these recommendations, the workgroup developed a conceptual model that: (1) Integrates parenting dimensions from the general parenting literature into the conceptualization of PA parenting, (2) draws on behavioral and developmental theory, and (3) emphasizes areas which have been neglected to date including precursors to PA parenting and effect modifiers.

Environmental factors associated with adults' participation in physical activity- a review

Background: Promoting physical activity is a public health priority, and changes in the environmental contexts of adults’ activity choices are believed to be crucial. However, of the factors associated with physical activity, environmental influences are among the least understood. Method: Using journal scans and computerized literature database searches, we identified 19 quantitative studies that assessed the relationships with physical activity behavior of perceived and objectively determined physical environment attributes. Findings were categorized into those examining five categories: accessibility of facilities, opportunities for activity, weather, safety, and aesthetic attributes. Results: Accessibility, opportunities, and aesthetic attributes had significant associations with physical activity. Weather and safety showed less-strong relationships. Where studies pooled different categories to create composite variables, the associations were less likely to be statistically significant. Conclusions: Physical environment factors have consistent associations with physical activity behavior. Further development of ecologic and environmental models, together with behavior-specific and context-specific measurement strategies, should help in further  understanding of these associations. Prospective studies are required to identify possible causal relationships.

Assessment of physical activity among primary school aged children: the Children's Leisure Activities Study (CLASS)

Overweight and obesity rates among children in Australia have increased twofold in the last decade. Physical activity is thought to play an important role in the prevention and treatment of childhood obesity. Children's physical activity data in Australia are incomplete and mainly based on parental proxy reports. One of the reasons for the lack of children's physical activity prevalence data in Australia is the difficulties of measurement. The aim of this study was to develop and examine a reliable, valid and feasible method for assessing physical activity among primary school aged children. A total of 112 grade 5 and 6 children and their parents were recruited from four state primary schools in the eastern and western suburbs of Melbourne. The test-retest reliability of a parental proxy physical activity questionnaire and a children's self report physical activity questionnaire was assessed. The criterion validity of the questionnaires was assessed using accelerometry. Findings suggest that the self report and proxy report questionnaires provided reliable measures of the type, frequency and duration of children's physical activity behaviour. Overall, the criterion validity of the questionnaires was poor. Although accelerometry as an objective measure shows promise, it does not provide the important physical activity behavioural and contextual information that is critical for the development of strategies to promote physical activity among children. We recommend that a combination of self report or proxy and objective measurement (using accelerometry or even pedometry) appears to be the current 'best buy' in the assessment of children's physical activity behaviour.

A hitchhiker's guide to assessing young people's physical activity : deciding what method to use

Researchers and practitioners interested in assessing physical activity in  children are often faced with the dilemma of what instrument to use. While there is a plethora of physical activity instruments to choose from, there is currently no guide regarding the suitability of common assessment instruments. The purpose of this paper is to provide a user’s guide for selecting physical activity assessment instruments appropriate for use with children and adolescents. While recommendations regarding specific instruments are not provided, the guide offers information about key attributes and considerations for the use of eight physical activity assessment approaches: heart rate monitoring; accelerometry; pedometry; direct observation; self-report; parent report; teacher report; and diaries/logs. Attributes of instruments and other factors to be considered in the selection of assessment instruments include: population (age); sample size; respondent burden; method/delivery mode; assessment time frame; physical activity information required (data output); data management; measurement error; cost (instrument and administration) and other limitations. A decision flow chart has been developed to assist researchers and practitioners to select an appropriate method of assessing physical activity. Five real-life scenarios are presented to illustrate this process in light of key instrument attributes. It is important that researchers, practitioners and policy makers understand the strengths and limitations of different methods of assessing physical activity, and are guided on selection of the most appropriate instrument/s to suit their needs.

Assessing free-living physical activity using accelerometry : practical issues for researchers and practitioners

Physical activity is an integral component of a healthy lifestyle, with relationships documented between physical activity, chronic diseases, and disease risk factors. There is increasing concern that many people are not sufficiently active to benefit their health. Consequently, there is a need to determine the prevalence of physical activity engagement, identify active and inactive segments of the population, and evaluate the effectiveness of interventions. The aim of the present study was to identify and explain a number of methodological and decision-making processes associated with accelerometry, which is the most commonly used objective measure of physical activity in child and adult research.

Specifically, this review addresses:
(a) pre-data collection decisions,
(b) data collection procedures,
(c) processing of accelerometer data, and
(d) outcome variables in relation to the research questions posed.

An appraisal of the literature is provided to help researchers and practitioners begin field-based research, with recommendations offered for best practice. In addition, issues that require further investigation are identified and discussed to inform researchers and practitioners of the surrounding debates.

Overall, the review is intended as a starting point for field-based physical activity research using accelerometers and as an introduction to key issues that should be considered and are likely to be encountered at this time.

Reliability of the modified child and adolescent physical activity and nutrition survey, physical activity (CAPANS-PA) questionnaire among chinese-australian youth

Background : Evidence suggests that differences exist in physical activity (PA) participation among Culturally and Linguistically Diverse (CALD) children and adolescents. It is possible that these differences could be influenced by variations in measurement technique and instrument reliability. However, culturally sensitive instruments for examining PA behaviour among CALD populations are lacking. This study tested the reliability of the Child and Adolescent Physical Activity and Nutrition Survey (CAPANS-PA) recall questionnaire among a sample of Chinese-Australian youth.
Methods : The psychometric property of the CAPANS-PA questionnaire was examined among a sample of 77 Chinese-Australian youth (aged 11 - 14 y) who completed the questionnaire twice within 7 days. Test-retest reliability of individual items and scales within the CAPANS-PA questionnaire was determined using Kappa statistics for categorical variables and intraclass correlation coefficients (ICC) for continuous variables.
Results : The CAPANS-PA questionnaire demonstrated acceptable test-retest reliability for frequency and duration of time spent in weekly Moderate to Vigorous Physical Activity (MVPA) (ICC ≥ 0.70) for all participants. Test-retest reliability for time spent in weekly sedentary activities was acceptable for females (ICC = 0.82) and males (ICC = 0.72).
Conclusions : The results suggest the CAPANS-PA questionnaire provides reliable estimates for type, frequency and duration of MVPA participation among Chinese-Australian youth. Further investigation into the reliability of the sedentary items within the CAPANS-PA is required before these items can be used with confidence. This study is novel in that the reliability of instruments among CALD groups nationally and internationally remains sparse and this study contributes to the wider body of available psychometrically tested instruments. In addition, this study is the first to our knowledge to successfully engage and investigate the basic health enhancing behaviours of Chinese-Australian adolescents.

Physical activity in young children : a systematic review of parental influences

The primary aim of this review was to identify and evaluate the strength of associations of the key parental factors measured in studies examining early childhood physical activity (PA). A systematic review of the literature, using databases PsychINFO, Medline, Academic Search Complete, PSYCHinfo, and CINHAL, published between January 1986 and March 2011 was conducted; 20 papers were relevant for the current review. While 12 parenting variables were identified, only 5 of these had been investigated sufficiently to provide conclusive findings. There were inconsistencies in the findings involving the social learning variable parental enjoyment and variables involving parental behaviours such as maternal depression and self-efficacy, and rules for sedentary behaviour, and parental perceptions, which included perceived importance of PA, fear of safety, and perception of child’s motor competence. Given these inconsistencies, a metaanalysis was conducted to determine whether the method of measuring PA (objective or subjective) influenced the strength of associations between the parental factors and young children’s PA. There was no difference in the strength of associations in the studies that used objective or subjective measurement (via parent self-report). Further investigation is needed to clarify and understand the specific parental influences and behaviours that are associated with PA in young children. In particular, longitudinal research is needed to better understand how parental influences and PA levels of children during the formative preschool and early elementary school years are associated.

Evaluating the travel, physical activity and carbon impacts of a 'natural experiment' in the provision of new walking and cycling infrastructure : methods for the core module of the iConnect study

Introduction Improving infrastructure to support walking and cycling is often regarded as fundamental to encouraging their widespread uptake. However, there is little evidence that specific provision of this kind has led to a significant increase in walking or cycling in practice, let alone wider impacts such as changes in overall physical activity or carbon emissions. Connect2 is a major new project that aims to promote walking and cycling in the UK by improving local pedestrian and cycle routes. It therefore provides a useful opportunity to contribute new evidence in this field by means of a natural experimental study.

Methods and analysis iConnect is an independent study that aims to integrate the perspectives of public health and transport research on the measurement and evaluation of the travel, physical activity and carbon impacts of the Connect2 programme. In this paper, the authors report the study design and methods for the iConnect core module. This comprised a cohort study of residents living within 5 km of three case study Connect2 projects in Cardiff, Kenilworth and Southampton, supported by a programme of qualitative interviews with key informants about the projects. Participants were asked to complete postal questionnaires, repeated before and after the opening of the new infrastructure, which collected data on demographic and socioeconomic characteristics, travel, car fuel purchasing and physical activity, and potential psychosocial and environmental correlates and mediators of those behaviours. In the absence of suitable no-intervention control groups, the study design drew on heterogeneity in exposure both within and between case study samples to provide for a counterfactual.

Ethics and dissemination The study was approved by the University of Southampton Research Ethics Committee. The findings will be disseminated through academic presentations, peer-reviewed publications and the study website (http://www.iconnect.ac.uk) and by means of a national seminar at the end of the study.

A review of preschool children's physical activity and sedentary time using objective measures

Identifying current physical activity levels and sedentary time of preschool children is important for informing government policy and community initiatives. This paper reviewed studies reporting on physical activity and time spent sedentary among preschool-aged children (2-5 years) using objective measures.

Child physical activity levels and associations with modifiable characteristics in centre-based childcare

Objective: To describe children's physical activity levels during childcare and associations with modifiable characteristics. Methods: A cross-sectional study of 328 preschool children (43% girls; age 3-5 years) and 145 staff from 20 long day care centres in the Hunter Region of NSW, Australia. Pedometers assessed child physical activity levels. Centre characteristics and staff attitudes and behaviours towards children's physical activity were assessed using surveys, interviews and observational audit. Results were analysed using descriptive statistics and linear regression. Results: Over the measurement period, average step count of children was 15.8 (SD=6.8) steps/minute. Four-year-olds had the highest step counts (16.4, SD=7.1, p=0.03) with no differences by sex. Step counts were significantly higher in centres that had a written physical activity policy (+3.8 steps/minute, p=0.03) and where staff led structured physical activity (+3.7 steps/minute, p<0.001) and joined in active play (+2.9 steps/minute, p=0.06). Conclusions: Written physical activity policy, structured staff-led physical activity and staff joining in active play were associated with higher levels of physical activity. Implications: Childcare physical activity interventions should consider including strategies to encourage written physical activity policies and support structured staff led physical activities.