Anna Timperio

Understanding physical activity environmental correlates : increased specificity for ecological models

Ecological models are now used to understand the complex array of factors that influence physical activity, resulting in a greater emphasis on environmental correlates. This selective review examines whether the predictive capacity of these models could be improved if behavior-specific measures of the environment were used to predict context-specific behaviors.

The association between television viewing and overweight among Australian adults participating in varying levels of leisure-time physical activity.

OBJECTIVES: To investigate the effect of physical activity on the association between television viewing and overweight (body mass index (BMI) ≥25 kg/m2).DESIGN: Cross-sectional study administered by interview to adults randomly selected from the electronic white pages.SUBJECTS: 3392 adults (64% response rate) from a representative population sample in the State of New South Wales, Australia.MEASUREMENTS: Self-reported height and weight, two-week leisure-time physical activity recall, one-week average television viewing recall.RESULTS: BMI and physical activity patterns were both associated with hours of television watched. Compared to those participants who reported watching less than one hour of television per day, those watching 1 to 2.5 hours were 93% more likely to be overweight (BMI≥25 kg/m2), those watching 2.5 to 4 hours were 183% more likely to be overweight, those watching more than 4 hours per day were four times more likely to be overweight. Physical activity was not directly associated with being overweight, but an interaction between activity and television watching was present. Respondents in the low, moderate and high physical activity categories who reported watching more than 4 hours of television per day were twice as likely to be overweight compared to those who watched less than one hour of television per day, irrespective of physical activity participation.CONCLUSIONS: With approximately half the Australian adult population overweight or obese, these findings indicate that public health strategies to reduce overweight and prevent weight gain may need to focus on reducing sedentary behaviours such as television viewing in addition to increasing physical activity.

A prospective examination of children's time spent outdoors, objectively measured physical activity and overweight

Objective: This study aimed to determine whether time spent outdoors was associated with objectively measured physical activity, body mass index (BMI) z-score and overweight in elementary-school aged children, cross-sectionally and prospectively over 3 years.Methods: Three-year cohort study with data collected during 2001 and 2004. Nineteen randomly selected state elementary schools across Melbourne, Australia. One hundred and eighty eight 5–6-year-old and 360 10–12-year-old children. Baseline parent reports of childrens time spent outdoors during warmer and cooler months, on weekdays and weekends. At baseline and follow-up, childrens moderate and vigorous physical activity (MVPA) was objectively assessed by accelerometry, and BMI z-score and overweight was calculated from measured height and weight.Results: Cross-sectionally, each additional hour outdoors on weekdays and weekend days during the cooler months was associated with an extra 27 min week−1 MVPA among older girls, and with an extra 20 min week−1 MVPA among older boys. Longitudinally, more time outdoors on weekends predicted higher MVPA on weekends among older girls and boys (5 min week−1). The prevalence of overweight among older children at follow-up was 27–41% lower among those spending more time outdoors at baseline.Conclusion: Encouraging 10–12-year-old children to spend more time outdoors may be an effective strategy for increasing physical activity and preventing increases in overweight and obesity. Intervention research investigating the effect of increasing time outdoors on childrens physical activity and overweight is warranted.

Personal, social and environmental determinants of educational inequalities in walking: a multilevel study

Objective: To investigate the contribution of personal, social and environmental factors to mediating socioeconomic (educational) inequalities in women’s leisure-time walking and walking for transport. Methods: A community sample of 1282 women provided survey data on walking for leisure and transport; educational level; enjoyment of, and self-efficacy for, walking; physical activity barriers and intentions; social support for physical activity; sporting/recreational club membership; dog ownership; and perceived environmental aesthetics and safety. These data were linked with objective environmental data on the density of public open space and walking tracks in the women’s local neighbourhood, coastal proximity and street connectivity. Results: Multilevel modelling showed that different personal, social and environmental factors were associated with walking for leisure and walking for transport. Variables from all three domains explained (mediated) educational inequalities in leisure-time walking, including neighbourhood walking tracks; coastal proximity; friends’ social support; dog ownership; self-efficacy, enjoyment and intentions. On the other hand, few of the variables examined explained educational variations in walking for transport, exceptions being neighbourhood, coastal proximity, street connectivity and social support from family. Conclusions: Public health initiatives aimed at promoting, and reducing educational inequalities in, leisure-time walking should incorporate a focus on environmental strategies, such as advocating for neighbourhood walking tracks, as well as personal and social factors. Further investigation is required to better understand the pathways by which education might influence walking for transport.

Mismatch between perceived and objective measures of physical activity environments

OBJECTIVES This study investigated the correspondence between measures of physical activity facilities obtained through self-report and objective audits; and identified the socio-demographic, cognitive and behavioral characteristics of those who perceive their physical activity environment to be less supportive than objective measures indicate. METHODS Self-report surveys were completed by 1540 women recruited from 45 neighborhoods in Melbourne, Australia. Women reported perceived access to physical activity facilities within 2 km from home, and also socio-demographic, cognitive and behavioral factors. Objective data on physical activity facilities within a 2 km pedestrian catchment area around womens homes were sourced. RESULTS There was relatively poor agreement between measures of access to physical activity facilities obtained via self-report and objective assessment. Mismatch between perceived and objectively-assessed environments was more common amongst younger and older women, and women of low income, with low self-efficacy for physical activity, who were less active, who reported using fewer facilities and who had lived in the neighborhood for less than 2 years. CONCLUSIONS Future studies of environmental determinants of physical activity should consider incorporating objective indices of access to facilities, or accounting for the systematic bias that may result from relying on self-report perceptions as an indicator of the actual physical activity environment.

Children's fruit and vegetable intake : Associations with the neighbourhood food environment

OBJECTIVE To examine associations between availability of different types of food outlets and childrens fruit and vegetable intake. METHOD Parents of 340 5-6 and 461 10-12 year-old Australian children reported how frequently their child ate 14 fruits and 13 vegetables in the last week in 2002/3. A geographic information system (GIS) was used to determine the availability of the following types of food outlets near home: greengrocers; supermarkets; convenience stores; fast food outlets; restaurants, cafés and takeaway outlets. Logistic regression analyses examined the likelihood of consuming fruit >or=2 times/day and vegetables >or=3 times/day, according to access to food outlets. RESULTS Overall, 62.5% of children ate fruit >or=2 times/day and 46.4% ate vegetables >or=3 times/day. The more fast food outlets (OR=0.82, 95%CI=0.67-0.99) and convenience stores (OR=0.84, 95%CI=0.73-0.98) close to home, the lower the likelihood of consuming fruit >or=2 times/day. There was also an inverse association between density of convenience stores and the likelihood of consuming vegetables >or=3 times/day (OR=0.84, 95%CI=0.74-0.95). The likelihood of consuming vegetables >or=3 times/day was greater the farther children lived from a supermarket (OR=1.27, 95%CI=1.07-1.51) or a fast food outlet (OR=1.19, 95%CI=1.06-1.35). CONCLUSION Availability of fast food outlets and convenience stores close to home may have a negative effect on childrens fruit and vegetable intake.

Perceptions of local neighbourhood environments and their relationship to childhood overweight and obesity

OBJECTIVES:To examine associations between parent and child perceptions of the local neighbourhood and overweight/obesity among children aged 5–6 and 10–12 y.DESIGN:Cross-sectional survey.SUBJECTS:In total, 291 families of 5–6-y-old and 919 families of 10–12-y-old children.MEASURES:Parents perceptions of local neighbourhood and perceived child access to eight local destinations within walking distance of home; 10–12-y-old childrens perception of local neighbourhood; socio-demographic characteristics (survey). Childrens height and weight (measured).RESULTS:No perceptions of the local neighbourhood were associated with weight status among 5–6-y-old children. Among 10–12-y-old children, those whose parents agreed that there was heavy traffic in their local streets were more likely to be overweight or obese (OR=1.4, 95% CI=1.0–1.8), and those whose parents agreed that road safety was a concern were more likely to be obese (OR=3.9, 95% CI=1.0–15.2), compared to those whose parents disagreed with these statements.CONCLUSIONS:This study suggests that parental perceptions of heavy traffic on local streets and concern about road safety may be indirect influences on overweight and obesity among 10–12-y-old children. Future work should also consider perceptions of the neighbourhood related to food choice.

Trends in children's physical activity and weight status in high and low socio-economic status areas of Melbourne, Victoria, 1985-2001.

Objective: To examine trends in active transport to and from school, in school sport and physical education (PE), and in weight status among children from high and low socio‐economic status (SES) areas in Melbourne, Victoria, between 1985 and 2001.

Evidence-based strategies to promote physical activity among children, adolescents and young adults: review and update.

This paper updates evidence reviewed in the first edition of Getting Australia Active on effective physical activity (PA) intervention strategies among children, adolescents and young adults. Intervention studies published between 1999 and September 2003 were identified using electronic databases and hand searching. A total of 28 discrete studies were identified (31 papers). Six of nine studies reported significant effects on child or youth PA in school settings. Those that incorporated whole-of-school approaches including curriculum, policy and environmental strategies appeared to be more effective than those that incorporated curriculum-only approaches. Five of 10 studies with children and two of five studies with adolescents reported increased PA or decreased sedentary behaviour in other settings. Interventions that included contact with families generally appeared to be most effective. One study with adolescents provided some evidence of the potential effectiveness of interventions based in primary care. Two of four papers reported modest short-term results among young adults, including increased PA stage of change or a higher likelihood of being adequately physically active, but none showed any evidence of sustained increases in PA. There is an urgent need for additional studies examining interventions aimed at young adults. Across the three life stages, future studies should include objective PA measures, longer-term follow-up, larger sample sizes, a specific focus on PA (rather than weight) and culturally-specific strategies that build evidence in Australian populations. Future studies should target high risk groups and a broad range of settings and strategies focusing on reducing sedentary behaviours as well as increasing PA.

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 users 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.