Abstract
Purpose:
To analyze the factors associated with commuting by bicycling and walking in adult participants from ELSA-Brasil (Longitudinal Study of Adult Health).
Design:
Cross-sectional.
Setting:
Six teaching/research institutions throughout Brazil.
Participants:
A total of 15 105 civil servants.
Measures:
Commuting by bicycling and walking was analyzed using the long-form International Physical Activity Questionnaire.
Analysis:
A hierarchical model containing possible factors associated with commuting by bicycling and walking was constructed. Crude and adjusted odds ratios were calculated using multinomial logistic regression.
Results:
Considering the 2 forms of commuting, 66% of the participants were being considered inactive or insufficiently active. In women, being “heavier,” feeling unsafe practicing physical activity, and being a former smoker were factors negatively associated with commuting by bicycling and walking. In men, active commuting was less common among those who were overweight or had abdominal obesity, those with a negative perception of safety, and those reporting that there was nowhere suitable in the neighborhood to practice physical activity.
Conclusion:
Obesity and negative perceptions in the neighborhood are associated with inactive or insufficiently active commuting. The relevance of this finding for public health is reinforce developing policies aimed at promoting health in Brazil and in other countries with similar characteristics.
Purpose
Commuting physical activity in the form of walking or bicycling is encouraged in various regions of the world as a healthy behavior. 1,2 Despite this evidence, commuting by walking and, principally, cycling, is not the norm, either in countries with a high socioeconomic level 3,4 or in those with intermediate to low economic levels. 5,6 A recent study conducted in Brazil found that only 33.4% of adults and 26.1% of the elderly population evaluated participated in active commuting (≥150 min/wk), showing that cycling or walking as a form of commuting is unusual, with consequently few positive repercussions on collective health. 7
Identifying the factors associated with commuting physical activity (cycling and walking) may be relevant when developing strategies to encourage this behavior in the general population. In another recent study conducted in Curitiba, Brazil, 11.2% of participants commuted by bicycle, with this habit being more common among men, among those of 30 to 39.9 years of age, those with a poor socioeconomic level, among bicycle owners, and those with a negative perception of their quality of life. 8
The environmental characteristics that may facilitate or deter active commuting 9 depend on the urban design, that is, the physical configuration of the environment (connectivity and proximity), the use of the land in terms of density and diversity, and the quality of urban conditions. 10 Studies conducted in high-income countries have shown a positive association between walkability and physical activity. Barcelona, for instance, is a city with a compact urban environment, diversity with respect to land use, a high density of bus stops, and good coverage of public transportation (47.3%) in relation to private transportation (22.17%). 11
Individual and socioeconomic factors may also influence the promotion of commuting by bicycling and walking. Individual factors such as chronic morbidities and excess weight or obesity negatively affect active commuting. 12 Studies conducted in Brazil focusing on socioeconomic factors showed that women who were older, with higher income levels, and with better education levels were more likely to be inactive with respect to commuting by bicycling and walking than men with the same characteristics. 13 -15
The marked social inequalities that characterize Brazil are also reflected in urban mobility, since they affect the choice of and access to means of public transportation, as well as where individuals live. 16 The housing policy in the country has reinforced spatial segregation, resulting in the poor segments of the population living in areas on the outskirts of cities where public services, including public transportation, are negligible. Therefore, belonging to the poorest segments of society means living in areas not serviced by public transport and having to walk long distances from home to a bus stop and then from a bus stop to the individual’s destination that is usually their workplace. 17
In this context, the contributions of the International Physical Activity Environment Network studies carried out in several areas of the world, including Brazil, stand out. Recent publication of this research group has shown that living in more densely populated areas, having a well-connected street network, more diverse land uses, and having more parks were positively associated with transport-related walking and/or cycling. 18
In Brazilian cities, the higher an individual’s socioeconomic level, the greater his or her mobility in terms of being able to cover greater distances in less time. This is particularly true in the case of the privileged upper classes of society who own automobiles. 16 A recent study carried out in Brazil showed an inverse association between family income and active commuting with gross family income acting as moderator of this association. 19
A considerable part of the literature published on physical activity and sedentariness originates in developed countries. 20 The identification of factors associated with commuting bicycling and walking in a developing country, through the use of demographic, social, environmental, behavioral, and biological determinants, is relevant to the international debate and should provide subsidies for public policies aimed at encouraging active commuting in countries with similar characteristics to those of Brazil. Such initiatives could contribute toward preventing various metabolic and cardiovascular disorders, consequently reducing costs to the health-care system. 21 Participants of the ELSA-Brasil cohort (Longitudinal Study of Adult Health) 21,22 with better perceived conditions for walking in neighborhoods were more active. This highlights the importance of actions within the context of cities for the development of healthy habits. 17 The purpose of the study was to evaluate the associated factors with commuting by bicycling and walking in Brazilian adults.
Methods
Sample
The sample for the Brazilian Longitudinal Study of Adult Health—ELSA-Brasil consisted of 15 105 volunteers, active and retired civil servants of 35 to 74 years of age at the time of recruitment from 6 institutions of higher education situated in the Brazilian cities of Salvador, Vitória, Belo Horizonte, Rio de Janeiro, São Paulo, and Porto Alegre. The participants were proportionally distributed across the 6 centers according to their eligibility. For a better distribution, recruitment goals were defined by sex, age, and occupational category. A statistical power analysis was conducted to determine an adequate sample size, and the size estimation was based on the main study outcomes. More details of the study methodology have already been published elsewhere. 21,22
Design
The ELSA-Brasil is a multicenter cohort study. In the present study, all the individuals who participated in the baseline (2008-2010) assessment and who provided information on physical activity and on their social, physical, and individual environments were included in the analysis, a total of 14 876 participants, with an exclusion rate of 1.5%.
The institutional internal review boards of all the 6 research centers involved approved the ELSA-Brasil study protocol. All the participants signed an informed consent form. The confidentiality of participants’ data was guaranteed, and their identity was concealed.
Measures
Data were collected by a team of trained interviewers and assessors, and certified by a quality control board capable of applying the study protocol in any ELSA-Brasil research center. 21 The study included face-to-face interviews to complete the questionnaires and to measure weight, height, and waist circumference. All participants, active or retired, were asked about their current and first jobs. If retired, they were asked about their first and last jobs. 22
The context of the neighborhood was defined based on self-reported evaluations. 17,23 The variables of interest were those referring to traffic conditions, individuals’ perceptions of their own safety when practicing physical activity, violence in the neighborhood, and conditions and opportunities for physical activity, including active commuting. The participants were asked questions such as “Is traffic heavy in your neighborhood?”; “Do you feel safe walking during the day and at night in your neighborhood?”; “Does your neighborhood provide facilities for people to be physically active (walking, biking)?” and “Are there many opportunities to practice physical activities or sports in clubs, gyms or other spaces in your neighborhood?”. Negative answers were coded as 0 and positive answers as 1.
Participants were weighed barefoot and wearing only a patient gown in the morning after an 8- to 12-hour fast. Weight was measured using a Toledo® electronic scale with a maximum capacity of 200 kg. A SECA® stadiometer was used to measure height, with the participant barefoot and standing straight, with their back to the stadiometer, heels together and toes apart at a 45° angle, and head in the Frankfort horizontal plane. Waist circumference was measured using a nonelastic tape at the midpoint between the lower rib and the iliac crest on the right side, or, if impossible to determine, at the umbilicus. Hip circumference was measured loosely at the level of the maximum protrusion of the gluteal muscles (hip), over the participant’s gown, using a nonelastic, flexible measuring tape. 24 Standards and recommended technical criteria were observed at all stages in the anthropometric evaluation. The equipment was installed and calibrated in all the study centers in accordance with standardized procedures.
The long-form International Physical Activity Questionnaire (IPAQ) was used to identify and quantify physical activity. The IPAQ is made up of questions on the frequency and duration of physical activity (moderate and vigorous walking) carried out at work, in commuting, in housework, and during leisure time. 25 In this study, only the commuting physical activity domain was used. Commuting by bicycling and walking was measured in minutes per week by multiplying the weekly frequency by the duration of each one of the activities performed. Participants were asked about their move from one place to another with the following questions: (1) how many days a week do you use the bike to get from one place to another? (2) on these days, how much time in total you pedal per day? (3) how many days a week do you walk to go from place to place? (4) in those days, how much time in total you walk in a day? The results were classified into 0 = inactive (<10 min/wk), 1 = insufficiently active (10-149 minutes per week spent in walking and/or cycling), and 2 = physically active (≥150 minutes per week spent in walking and/or cycling). 26
Analysis
Latent class analysis (LCA) was used to elucidate the social and anthropometric constructs. Latent class analysis describes unobserved characteristics by modeling the observed response patterns of variables that capture the behavior of the construct of interest. Latent class analysis is used to determine mutually exclusive groups and assumes conditional independence. We estimated 2 parameters for each latent variable using LCA: (1) class prevalence, which measured the proportion of individuals assigned to each latent class and (2) the conditional probabilities, that is, the response patterns of the observed variables in a given latent class. 27
The optimal number of classes to characterize the data is selected in LCA based on different strategies, including an interpretation of the estimated conditional probabilities or using Akaike Information Criteria, 28 the Schwarz Bayesian Information Criterion (BIC), the sample-size-adjusted BIC, 29,30 the Lo-Mendell-Rubin likelihood ratio test, and bootstrap likelihood ratio test. A measure of model quality is entropy, which is related to a posteriori classification uncertainty. Entropy values close to 1 indicate highly discriminatory classes. 31 The conditional independence assumption was evaluated using bivariate residuals. Participants were classified according to their most likely latent class membership.
Participants’ anthropometric profile was classified using a construct that encompassed the variables: body mass index, abdominal obesity, and waist-to-hip ratio, according to the conditional probabilities in the LCA model. The 2-class latent variable was “slimmer” or “heavier.” Likewise, to define the socioeconomic levels “low,” “intermediate,” and “high,” a 3-class LCA model was constructed based on the variables reported by participants: education level, income, social class, and intergenerational social mobility.
In addition to the anthropometric and socioeconomic constructs and the variables regarding the neighborhood, other factors associated with commuting physical activity that were analyzed included age, self-reported skin color/ethnicity, smoking, and whether the participant provided care for sick or dependent family members.
Commuting by bicycling and walking was the dependent variables, whereas the independent variables were grouped into blocks: distal block (latent variable for socioeconomic level), intermediate block (traffic conditions for the practice of physical activity, the participant’s perception of safety for the practice of physical activity, the participant’s perception of violence in the neighborhood, and the conditions and opportunities for the practice of physical activity), and the proximal block (latent variable for anthropometric status, smoking, age, self-reported skin color/ethnicity, and whether the participant cared for sick or dependent family members; Figure 1). 32

Multivariate hierarchical model used to analyze the factors associated with commuting physical activity in adult participants of the ELSA-Brasil. Adapted from Pitanga et al. 32
All analyses were stratified by gender since there is an accumulation of evidence in the scientific literature, 33 showing differences between males and females regarding their use of work and leisure time that influence decisions in the organization of daily life and, consequently, in physical activity in its various domains.
Crude and adjusted odds ratios were estimated together with their 95% confidence intervals using multinomial logistic regression, taking as a reference the classification inactive with respect to commuting physical activity to discriminate against potential-associated factors of hierarchical levels (Figure 1). The strategy used for the entry of variable blocks was the forward stepwise method, in the following order: distal block, intermediate block, and proximal block. In the steps of the hierarchical analysis, variables with P values <.1 remained in the model. The statistical software program STATA, version 12.0, and MPlul, version 7.3 were used throughout the statistical analysis.
Results
Cycling was reported by 4.3% of the participants, with less than 2% reporting the use of a bicycle for more than 150 min/wk. A larger proportion of the participants reported walking as a commuting physical activity, with 32.7% being considered active, 39.3% insufficiently active, and 28% inactive. Considering the 2 forms of commuting physical activities, 34% of the participants cycled and/or walked for more than 150 min/wk, with men being slightly more active than women (36.1% and 32.2%, respectively; Table 1). The main criteria for the choice of the LCA models were the interpretation of the estimated conditional probabilities, the entropy and the probabilities of error classification. The entropies for the 2-class LCA model for anthropometric status were 1.000 and 0.987, respectively, for women and men. The corresponding entropies for the 3-class LCA model for socioeconomic level were 0.838 and 0.843. Detailed results for the selected LCA models for anthropometric status and socioeconomic levels are available as supplemental material.
Characteristics of the Study Population According to Sex.a
aELSA-Brasil, 2008 to 2010.
In the hierarchical multinomial logistic regression model for the women, the least active in commuting compared to inactive (the reference category) or insufficiently active, were those classified as having a less favorable anthropometric status, that is, the “heavier” participants, those who did not feel safe practicing physical activity and former smokers. The most active women tended to be older, to have poorer socioeconomic levels, to describe their ethnicity as black or indigenous, and to describe traffic in their neighborhood as heavy (Table 2).
Hierarchical Analysis of the Association Between Commuting Bicycling/Walking and Socioeconomic, Environmental, Individual, and Cultural Factors in Women of 35 to 74 years of age.a
aLongitudinal Study of Adult Health—ELSA-Brasil, 2008-2010.
bModel adjusted for socioeconomic-level latent variable.
cModel adjusted for sociodemographic and environmental variables.
dModel adjusted for sociodemographic, environmental, and individual variables.
Overweight men and those with excess abdominal obesity, those with a negative perception regarding safety, and those reporting a lack of suitable conditions for the practice of physical activity in the neighborhood were the least active in commuting as compared to the inactive (reference) and insufficiently active groups. The most active participants were those with poorer socioeconomic levels, those who described themselves as black, those who reported traffic in the neighborhood as being heavy, those who perceived their neighborhood as being violent, and those who reported having to care for sick or dependent relatives in the home and older participants. Participation in commuting physical activity tended to increase with age (Table 3).
Hierarchical Analysis of the Association Between Commuting Bicycling/walking and Socioeconomic, Environmental, Individual, and Cultural Factors in Men aged 35 to 74 years.a
aLongitudinal Study of Adult Health—ELSA-Brasil, 2008 to 2010.
bModel adjusted for socioeconomic-level latent variable.
cModel adjusted for sociodemographic and environmental variables.
dModel adjusted for sociodemographic, environmental, and individual variables.
Discussion
In the present study, 34% of the participants walked or cycled to work for a minimum of 150 minutes per week. Other studies have reported that men tend to be more physically active in the domains of leisure, commuting, and occupational activities, whereas women are more active in the domestic domain, 13 which may be explained by the different gender roles and by the unequal division of family labor. In Brazil, as in many countries, women undertake a double workload and are obliged to divide their time between their professional and domestic lives, with implications in task prioritization. 34
Men and women from lower socioeconomic strata tended to participate more in commuting by bicycling and walking. This finding reinforces the idea that this is the result of social inequalities in urban mobility rather than the adoption of a healthy habit. 19 For the less privileged commuting, which is often difficult, partially because of the poor road surfaces of the less affluent neighborhoods, represents an accumulation of difficulties with respect to the access of these individuals to public services. 16 On the other hand, the poor quality of public transportation affects the choice of those who make up the more privileged social classes to commute by car.
Also in ELSA-Brasil, the privileged social classes are predominantly white, and this interpretation is reinforced by the finding that the female participants of the ELSA-Brasil who reported their ethnicity/skin color as black or indigenous and the male participants who reported their ethnicity/skin color as black were associated with a greater likelihood of participating in commuting physical activity. This finding differs from the findings of studies conducted in the United States, showing whites to be more active in commuting physical activity. 34,35 In Brazil, the black population has historically had more social inequalities insofar as their access to goods and services, including housing and public transportation, is concerned. The socioeconomic inequalities are compounded by racism and by discrimination regarding access to the labor market and housing, which may explain the independent effect of ethnicity/skin color even after adjustment at the socioeconomic level. This finding merits further investigation.
In the ELSA-Brasil cohort, the individuals tended to participate more in commuting by bicycling and walking as they aged. Recently published data from the ELSA-Brasil 32 have already shown that both age in women and the state of being retired for both sexes increase the practice of leisure-time physical activity. Benedetti et al 36 reported that 59.3% of the elderly population maintained the same characteristics of physical activity both in their free time and in commuting physical activity. It is assumed that retired individuals have more free time available for both leisure time activities and commuting physical activity.
In the present study, the individuals who perceived the traffic in their neighborhood as heavier participated more in commuting by bicycling and walking, whereas those who perceived their neighborhood as unsafe, on the other hand, were less likely to participate in commuting physical activity. Conflicting results were found in a study conducted in the state of Bahia in which lack of safety during the practice of physical activity and the perception of danger/violence in the neighborhood had no effect on behavior in relation to commuting bicycling and walking. 37 In fact, few studies have dealt with the association between perceptions of violence/policing and physical activity, taking into consideration that areas in which policing is more intense may provide a greater sensation of safety and consequently increase the possibility that residents will practice physical activity.
Women who were former smokers were less likely to be active in commuting. An interfering factor here is the weight gain commonly associated with stopping smoking that contributes to low levels of physical activity. 36 Smokers are more likely to be sedentary, since their capacity to perform physical activity may be reduced due to physiological alterations and the development of diseases that hamper the practice of physical activity.
A paradoxical finding of the present study was the positive association between caring for sick or dependent family members and an increase in commuting by bicycling and walking in men alone. Women were more likely to report this type of responsibility; however, it had no effect on the amount of physical activity they performed. The type of support provided is unknown and may range from helping with personal hygiene to assisting financially, 38 and this paradox needs to be investigated further.
A possible limitation of the study lies in the fact that information on physical activity was obtained from self-reported questionnaires; however, these questionnaires have been widely used in national and international studies with good validity and reproducibility in Brazil. 25 The ELSA-Brasil is a longitudinal study, and it is expected that more objective measures such as accelerometry will be incorporated in the future, which may increase the validity of the data on physical activity. One of the strongpoints of the study is the large sample size and the method of data production in which the participants were interviewed and examined by a supervised trained team with rigorous quality control. In addition to guaranteeing quality through the strategy of certification and re-certification of the trained supervised group to perform interviews and take measurements, the study was continuously supported by a data quality control assurance committee. 39
A further limitation of the study concerns the dependent variable itself—commuting physical activity, which encompassed walking and cycling. The number of individuals participating in these 2 forms of exercise was quite different, with most individuals choosing to walk. Very few participants reported using a bicycle for commuting.
In conclusion, the principal variables that positively affected bicycling or walking as a form of commuting were poor socioeconomic level, age, heavy traffic in the neighborhood, ethnicity/skin color, and having to care for sick or dependent family members. On the other hand, a perceived lack of safety in the neighborhood, obesity, smoking, and a lack of suitable conditions for bicycling or walking in the neighborhood were factors that negatively affected commuting physical activity.
These results may prove useful when developing policies aimed at promoting health in Brazil and in other countries with similar characteristics. These findings provide further fuel for the international debate on the adoption of healthy behaviors, introducing new evidence on the factors that influence such behaviors in a developing country marked by social inequalities in urban mobility and their association with health.
So What? Implications for Health Promotion Practitioners and Researchers
What is already known on this topic?
Different demographic, social, environmental, behavioral, and biological factors may influence the promotion of commuting by bicycling and walking.
What does this article add?
The results found in this article add to the existing literature information on the main variables demographic, social, environmental, behavioral, and biological that can influence the active displacement of populations. In this way, comparisons can be made with other national and international studies.
What are the implications for health promotion practice or research?
Formulating an explanatory model for identifying factors associated with adults who commute by bicycle or on foot in a developing country, through the use of demographic, social, environmental, behavioral, and biological determinants, is relevant and should provide subsidies for public policies of physical promotion.
Footnotes
Acknowledgments
The authors wish to express their gratitude to the volunteers who participated in this study.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The ELSA-Brasil baseline study was supported by the Brazilian Ministry of Health (Science and Technology Department) and the Brazilian Ministry of Science and Technology (Financiadora de Estudos e Projetos and CNPq National Research Council), grants 01 06 0010.00 RS, 01 06 0212.00BA, 01 06 0300.00 ES, 01 06 0278.00 MG, 01 06 0115.00SP, and 01 06 0071.00 RJ. PATRÃO AL was supported by Project Attraction Young Talents, Science without Borders, CAPES, project A061/2013.
Supplemental Material
Supplementary material for this article is available online.
References
Supplementary Material
Please find the following supplemental material available below.
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