Klaus Gebel

Built environment, physical activity, and obesity: What have we learned from reviewing the literature?

To evaluate the growing literature on the built environment and physical activity/obesity, we conducted a review of review papers. Through a systematic search, we identified 36 reviews that met the inclusion criteria and evaluated these reviews based on key information provided, review methodology, and specificity regarding measurement. We also analyzed research gaps and areas of improvement identified by previous reviews and propose a research agenda. Future studies should develop complex conceptual and statistical models that include moderators and mediators, improve objective and perceived measures of the built environment, and strengthen evidence of causality through better research designs.

Correlates of Non-Concordance between Perceived and Objective Measures of Walkability

BackgroundObjective and self-reported physical environmental attributes have been related to physical activity.PurposeWe examined the characteristics of adults who are resident in objectively identified high walkable neighborhoods but whose perceptions of neighborhood attributes are not concordant with objective attributes relating to high walkability.MethodsNeighborhood built-environment attributes relating to walkability (dwelling density, intersection density, land use mix, and net retail area) were determined objectively, using Geographic Information System databases; data on corresponding perceptions of local environment attributes (from the Neighborhood Environment Walkability Scale) were derived from a self-completion survey of a socially diverse sample of 2,650 adults aged 19 to 65. Objective and perceived walkability attributes were categorized using median splits, and correlates of non-concordance were determined using multiple logistic regression models.ResultsThere was a fair overall agreement between objectively determined walkability and perceived walkability (Kappa = 0.35, 95% CI = 0.31–0.39). Among those resident in objectively assessed high walkable areas (n = 1,063), 32.1% perceived them to be low walkable; conversely, 32.7% (n = 1,021) resident in objectively determined low walkability areas perceived them to be high. For residents of objectively determined high walkable areas, the characteristics that differentiated those with perceptions of low walkability (non-concordant perceptions) from those with concordant perceptions of high walkability were: not being university-educated (OR = 1.47, 95% CI = 1.06–2.04); having lower household incomes (OR = 1.54, 95% CI = 1.09–2.17); being overweight (OR = 1.46, 95% CI = 1.03–2.07); and walking fewer days per week for transport (OR = 1.75, 95% CI = 1.11–2.70). Higher walking times and more positive cognitive variables were noted among participants who lived in a neighborhood with low walkability that was perceived as high compared to those who lived in a high walkable environment that was perceived as low walkable.ConclusionAdults with lower educational attainment and lower incomes, who were overweight, or who were less physically active for transportation purposes, were more likely to misperceive their high walkable neighborhood as low walkable. There is the potential for physical activity promotion and persuasion strategies to address non-concordant perceptions, especially among those who live in high walkable environments but perceive them to be low and also among those who are socially disadvantaged and are less active. Perceptions of environmental attributes may be more strongly correlated with cognitive antecedents and with behavior than are objective measures.

Mismatch between perceived and objectively assessed neighborhood walkability attributes: Prospective relationships with walking and weight gain

We examined prospectively whether persons who perceive their objectively measured high walkable environment as low walkable decrease their walking more and gain more weight than those with matched perceptions. Walkability was measured objectively using GIS. Corresponding perceptions were collected using the Neighborhood Environment Walkability Scale from 1027 urban Australian adults. Objective and perceived measures were dichotomized and categories of match and mismatch were created. Overall, walking levels decreased and BMI increased significantly over the four year follow-up period. Those who perceived high walkability, dwelling density or land use mix as low decreased their walking for transport significantly more than those with matched perceptions. Those who perceived high walkability, land use mix or retail density as low increased their BMI significantly more than those with concordant perceptions. These prospective findings corroborate recommendations from previous cross-sectional studies. Interventions to improve negative perceptions of walkability among those living in high walkable areas may be a relevant public health intervention to increase physical activity and support weight maintenance.

Effect of Moderate to Vigorous Physical Activity on All-Cause Mortality in Middle-aged and Older Australians

IMPORTANCE Few studies have examined how different proportions of moderate and vigorous physical activity affect health outcomes. OBJECTIVE To examine whether the proportion of total moderate to vigorous activity (MVPA) that is achieved through vigorous activity is associated with all-cause mortality independently of the total amount of MVPA. DESIGN, SETTING, AND PARTICIPANTS We performed a prospective cohort study with activity data linked to all-cause mortality data from February 1, 2006, through June 15, 2014, in 204,542 adults aged 45 through 75 years from the 45 and Up population-based cohort study from New South Wales, Australia (mean [SD] follow-up, 6.52 [1.23] years). Associations between different contributions of vigorous activity to total MVPA and mortality were examined using Cox proportional hazards models, adjusted for total MVPA and sociodemographic and health covariates. EXPOSURES Different proportions of total MVPA as vigorous activity. Physical activity was measured with the Active Australia Survey. MAIN OUTCOMES AND MEASURES All-cause mortality during the follow-up period. RESULTS During 1,444,927 person-years of follow-up, 7435 deaths were registered. Compared with those who reported no MVPA (crude death rate, 8.34%), the adjusted hazard ratios for all-cause mortality were 0.66 (95% CI, 0.61-0.71; crude death rate, 4.81%), 0.53 (95% CI, 0.48-0.57; crude death rate, 3.17%), and 0.46 (95% CI, 0.43-0.49; crude death rate, 2.64%) for reporting 10 through 149, 150 through 299, and 300 min/wk or more of activity, respectively. Among those who reported any MVPA, the proportion of vigorous activity revealed an inverse dose-response relationship with all-cause mortality: compared with those reporting no vigorous activity (crude death rate, 3.84%) the fully adjusted hazard ratio was 0.91 (95% CI, 0.84-0.98; crude death rate, 2.35%) in those who reported some vigorous activity (but <30% of total activity) and 0.87 (95% CI, 0.81-0.93; crude death rate, 2.08%) among those who reported 30% or more of activity as vigorous. These associations were consistent in men and women, across categories of body mass index and volume of MVPA, and in those with and without existing cardiovascular disease or diabetes mellitus. CONCLUSIONS AND RELEVANCE Among people reporting any activity, there was an inverse dose-response relationship between proportion of vigorous activity and mortality. Our findings suggest that vigorous activities should be endorsed in clinical and public health activity guidelines to maximize the population benefits of physical activity.

Co-benefits of designing communities for active living: an exploration of literature

To reverse the global epidemic of physical inactivity that is responsible for more than 5 million deaths per year, many groups recommend creating “activity-friendly environments.” Such environments may have other benefits, beyond facilitating physical activity, but these potential co-benefits have not been well described. The purpose of the present paper is to explore a wide range of literature and conduct an initial summary of evidence on co-benefits of activity-friendly environments. An extensive but non-systematic review of scientific and “gray” literature was conducted. Five physical activity settings were defined: parks/open space/trails, urban design, transportation, schools, and workplaces/buildings. Several evidence-based activity-friendly features were identified for each setting. Six potential outcomes/co-benefits were searched: physical health, mental health, social benefits, safety/injury prevention, environmental sustainability, and economics. A total of 418 higher-quality findings were summarized. The overall summary indicated 22 of 30 setting by outcome combinations showed “strong” evidence of co-benefits. Each setting had strong evidence of at least three co-benefits, with only one occurrence of a net negative effect. All settings showed the potential to contribute to environmental sustainability and economic benefits. Specific environmental features with the strongest evidence of multiple co-benefits were park proximity, mixed land use, trees/greenery, accessibility and street connectivity, building design, and workplace physical activity policies/programs. The exploration revealed substantial evidence that designing community environments that make physical activity attractive and convenient is likely to produce additional important benefits. The extent of the evidence justifies systematic reviews and additional research to fill gaps.

Driving: a road to unhealthy lifestyles and poor health outcomes

Background Driving is a common part of modern society, but its potential effects on health are not well understood. Purpose The present cross-sectional study (n = 37,570) examined the associations of driving time with a series of health behaviors and outcomes in a large population sample of middle-aged and older adults using data from the Social, Economic, and Environmental Factor Study conducted in New South Wales, Australia, in 2010. Methods Multiple logistic regression was used in 2013 to examine the associations of usual daily driving time with health-related behaviors (smoking, alcohol use, diet, physical activity, sedentary behavior, sleep) and outcomes (obesity, general health, quality of life, psychological distress, time stress, social functioning), adjusted for socio-demographic characteristics. Results Findings suggested that longer driving time was associated with higher odds for smoking, insufficient physical activity, short sleep, obesity, and worse physical and mental health. The associations consistently showed a dose-response pattern and more than 120 minutes of driving per day had the strongest and most consistent associations with the majority of outcomes. Conclusion This study highlights driving as a potential lifestyle risk factor for public health. More population-level multidisciplinary research is needed to understand the mechanism of how driving affects health.

Benefits of exercise

[Extract] Physical activity is defined as body movement produced by skeletal muscle that results in energy expenditure above resting level and can be accumulated at any time, for example, during work, household, transportation, or during leisure time. Exercise is a subset of leisure-time physical activity that is usually structured, planned, repetitive, and has the purpose of providing recreation, improving or maintaining physical fitness, or enhancing other components of health or well-being (US Department of Health and Human Services, 1996).This encyclopedia advances the understanding of behavioral medicine principles and clinical applications among researchers and practitioners in medicine, psychology, public health, epidemiology, nursing, and social work. In addition, the encyclopedia provides useful synergies for sociologists, anthropologists, and undergraduates with some interest in the interface of human health and behavior. Areas covered include quality of life and lifespan issues; population, health policy, and advocacy issues; health promotion and disease prevention; behavioral care in all types of settings; biological, psychological, and person factors in health behavior change; professional development and practice-related issues; and much more. This encyclopedia is the first resource to which readers turn for factual, relevant, and comprehensive information to aid in delivering the highest quality services.

Walkability parameters, active transportation and objective physical activity: moderating and mediating effects of motor vehicle ownership in a cross-sectional study

BackgroundNeighborhood walkability has been associated with physical activity in several studies. However, as environmental correlates of physical activity may be context specific, walkability parameters need to be investigated separately in various countries and contexts. Furthermore, the mechanisms by which walkability affects physical activity have been less investigated. Based on previous research, we hypothesized that vehicle ownership is a potential mediator. We investigated the associations between walkability parameters and physical activity, and the mediating and moderating effects of vehicle ownership on these associations in a large sample of Swedish adults.MethodsResidential density, street connectivity and land use mix were assessed within polygon-based network buffers (using Geographic Information Systems) for 2,178 men and women. Time spent in moderate to vigorous physical activity was assessed by accelerometers, and walking and cycling for transportation were assessed by the International Physical Activity Questionnaire. Associations were examined by linear regression and adjusted for socio-demographic characteristics. The product of coefficients approach was used to investigate the mediating effect of vehicle ownership.ResultsResidential density and land use mix, but not street connectivity, were significantly associated with time spent in moderate to vigorous physical activity and walking for transportation. Cycling for transportation was not associated with any of the walkability parameters. Vehicle ownership mediated a significant proportion of the association between the walkability parameters and physical activity outcomes. For residential density, vehicle ownership mediated 25% of the association with moderate to vigorous physical activity and 20% of the association with the amount of walking for transportation. For land use mix, the corresponding proportions were 34% and 14%. Vehicle ownership did not moderate any of the associations between the walkability parameters and physical activity outcomes.ConclusionsResidential density and land use mix were associated with time spent in moderate to vigorous physical activity and walking for transportation. Vehicle ownership was a mediator but not a moderator of these associations. The present findings may be useful for policy makers and city planners when designing neighborhoods that promote physical activity.

Validity and reliability of Fitbit Flex for step count, moderate to vigorous physical activity and activity energy expenditure

Objectives To examine the validity and reliability of the Fitbit Flex against direct observation for measuring steps in the laboratory and against the Actigraph for step counts in free-living conditions and for moderate-to-vigorous physical activity (MVPA) and activity energy expenditure (AEE) overall. Methods Twenty-five adults (12 females, 13 males) wore a Fitbit Flex and an Actigraph GT3X+ during a laboratory based protocol (including walking, incline walking, running and stepping) and free-living conditions during a single day period to examine measurement of steps, AEE and MVPA. Twenty-four of the participants attended a second session using the same protocol. Results Intraclass correlations (ICC) for test-retest reliability of the Fitbit Flex were strong for walking (ICC = 0.57), moderate for stair stepping (ICC = 0.34), and weak for incline walking (ICC = 0.22) and jogging (ICC = 0.26). The Fitbit significantly undercounted walking steps in the laboratory (absolute proportional difference: 21.2%, 95%CI 13.0–29.4%), but it was more accurate, despite slightly over counting, for both jogging (6.4%, 95%CI 3.7–9.0%) and stair stepping (15.5%, 95%CI 10.1–20.9%). The Fitbit had higher coefficients of variation (Cv) for step counts compared to direct observation and the Actigraph. In free-living conditions, the average MVPA minutes were lower in the Fitbit (35.4 minutes) compared to the Actigraph (54.6 minutes), but AEE was greater from the Fitbit (808.1 calories) versus the Actigraph (538.9 calories). The coefficients of variation were similar for AEE for the Actigraph (Cv = 36.0) and Fitbit (Cv = 35.0), but lower in the Actigraph (Cv = 25.5) for MVPA against the Fitbit (Cv = 32.7). Conclusion The Fitbit Flex has moderate validity for measuring physical activity relative to direct observation and the Actigraph. Test-rest reliability of the Fitbit was dependant on activity type and had greater variation between sessions compared to the Actigraph. Physical activity surveillance studies using the Fitbit Flex should consider the potential effect of measurement reactivity and undercounting of steps.

Improving Current Practice in Reviews of the Built Environment and Physical Activity

Over the last decade, there has been a marked increase in studies about built environments and physical activity. As the number of publications is growing rapidly, literature reviews play an important role in identifying primary studies and in synthesizing their findings. However, many of the reviews of effectiveness in this field demonstrate methodological limitations that might lead to inaccurate portrayals of the evidence. Some literature reviews a priori excluded intervention studies even though they provide the strongest level of evidence. The label ‘systematic review’ has mostly been used inappropriately. One of the major criteria of a systematic review that is hardly ever met is that the quality of the primary studies needs to be assessed and this should be reflected in the synthesis, presentation and interpretation of results. With few exceptions, ‘systematic’ reviews about environments and physical activity did not refer to or follow the QUORUM or PRISMA statements. This commentary points out the usefulness of the PRISMA statement to standardize the reporting of methodology of reviews and provides additional guidance to limit sources of bias in them. The findings and recommendations from this article can help in moving forward the synthesis of evidence of effectiveness not only in built environments and physical activity, but also more broadly in exercise science and public health.