We found that people with a workplace environment that had more cultural and physical supports were more likely to walk or bicycle to work. However, this relationship between workplace supports and active commuting behavior appeared to be moderated by sex, as such associations were significant only for women in our sample. For women, the presence of at least 1 cultural support, in particular their perceptions that other coworkers walk or bicycle to work, was associated with almost a threefold increase in the likelihood of active commuting at least once per week. Likewise, women who reported 1 physical support were more than 3 times as likely to actively commute, while women with 2 or 3 physical supports were 10 times as likely to do so. Furthermore, the cumulative effect of having at least 1 cultural and at least 1 physical workplace support was strongest for women in this study. To our knowledge, few, if any, studies have explored how influences on active commuting differ by sex. One study (
26) reported that women had stronger preferences for community infrastructure for bicycling (eg, off-road routes with separation from motorized traffic), and the same may be true for workplace supports for active commuting. Additionally, women may be more concerned with cleanliness and tidiness of their appearance compared with men, explaining the importance of the availability of showers and lockers to support active commuting. Women generally report lower levels of overall physical activity and lower self-efficacy for physical activity (
27), but additional qualitative and experimental research is needed to further explore the reasons why workplace supports appear to differentially benefit active commuting among women.
When the sample was stratified by age, the presence of 2 or more physical workplace supports was associated with a greater likelihood of active commuting for both younger and older adults. However, with respect to cultural supports, the significant relationship observed for the full sample failed to materialize for either the younger or older subgroups. When considered in isolation, though, greater perceptions of the number of coworkers who actively commute was related to increased active commuting behavior for both age groups. Having a larger percentage of fellow employees who walk or bicycle to work may create an environment that tolerates, fosters, or reinforces similar behavior among colleagues. Future research can shed light on the psychological (eg, modeling, affiliation) or behavioral (eg, "walkpooling" or "bicyclepooling") mechanisms behind the relevance of having coworkers who actively commute.
The primary strength of our study was its novelty in considering supports in workplace settings that may influence active commuting. However, our study does have limitations. First, our data were collected from a convenience sample that was small. Because the exact number of people who were eligible and had the opportunity to complete the survey is unknown, we were unable to calculate a response rate. We also could not entirely rule out the possibility that respondents were clustered in workplaces, although some data collected in the survey (closest intersection to workplace) suggested that the participants originated from various locations. Future studies may examine our research questions with a larger, random sample of employees, potentially in a multilevel framework. Second, we used self-report measures of both the workplace environment and active commuting behavior (although perceived measures of workplace supports may be more important than objective indicators). Third, our online survey format may have excluded potential respondents who did not have access to the Internet. Finally, our sample was well-educated and almost exclusively white, which limits the generalizability of our findings.
Our results substantiate the impact of a social-ecological approach for promoting active commuting. Many studies have examined the utility of workplace interventions for promoting physical activity, with mixed results. For example, Proper et al (
28) reviewed 26 studies of worksite interventions to promote physical activity or fitness and found evidence of a positive effect of such programs on physical activity and musculoskeletal disorders and found limited to inconclusive evidence for a positive effect on fatigue, physical fitness, general health, blood serum lipids, and blood pressure. Dishman et al (
29) also reviewed 26 studies that delivered physical activity interventions through worksites and concluded that the mean effect of the interventions was heterogeneous and small. However, most studies included in those reviews employed largely individual-level approaches (eg, goal setting) to promote leisure-time (rather than utilitarian) physical activity. Our findings indicate that providing a supportive physical and cultural environment that promotes active commuting is associated with higher rates of walking and bicycling to work, which in turn can have significant health benefits (
7-
11).
In terms of health promotion, our results provide a foundation for intervention strategies, including potential physical changes to workplaces, such as the addition of showers, bicycle racks, and covered and secure bicycle parking. Likewise, a workplace culture that supports active commuting can influence mode of travel to work. The social support that results when a large number of workers actively commute, either collectively or individually, can be reinforcing (
30). Such practices may be facilitated by team challenges or other worksite events focused around active commuting. Employer and government policies may also foster a climate supportive of active commuting. For example, offering tax breaks, parking refunds, health insurance premium reductions, or other financial incentives may encourage active commuting among employees. In combination with traditional individually targeted approaches, these institutional strategies can make active commuting more attractive. Moreover, our data suggest that such strategies may be especially influential for encouraging active commuting among women, a subgroup that generally exhibits lower rates of active transportation and overall physical activity (
31). As workplaces increasingly adopt such practices, documenting the costs of such investments in comparison with the savings enjoyed by both employees (eg, reduced health care costs) and employers (eg, reduced sick time) is important.
Our study adds to the small body of existing literature concerning factors associated with active commuting among adults and contributes to our understanding of social-ecological influences on this behavior beyond the individual. More research is needed to evaluate interventions that aim to promote active commuting (
20), but making changes to workplace infrastructure and policies may be effective avenues for increasing rates of active commuting and improving employee health.