We investigated the influence of social factors on physical activity among a large sample of low-income, multiethnic public housing residents. In a population with low average levels of physical activity, we found that several social factors were important correlates of pedometer-measured physical activity.
With respect to social networks, residents with no or very few social ties took an average of more than 1500 fewer steps per day than did residents with a larger social network. This difference is striking when one considers that the mean steps per day among this population is already very low (~5600), close to previously identified thresholds for sedentary physical activity and well below levels of physical activity among the general US population.47,53–55
This finding suggests that having limited social networks may be a risk factor for physical inactivity among this population. Our findings are consistent with earlier literature on social networks and physical activity,19–21
and suggest that the quantity of social ties has important implications for physical activity among low-income housing residents.
Differences in this association were found by age and by race/ethnicity, such that social networks were most important among Hispanic and younger residents (aged 18–35 years). Among young adults and Hispanics, social network ties was a very strong correlate, with younger and Hispanic socially isolated residents taking about 2500 fewer steps per day (equivalent to more than a mile a day) than did their counterparts with more social network ties. Among young adults, this social isolation may influence motivation and opportunities to be active, or may reflect lack of social engagement or participation in unhealthy behaviors that reduce mobility. Among some Hispanics, issues related to immigration status (e.g., living in and adjusting to a new country) may enhance isolation and limit opportunities for activity. More research among larger samples is needed to investigate these issues, using both qualitative and quantitative methods.
A number of mechanisms exist through which social networks may influence physical activity, including providing access to role models, forming a sense of connectedness with others, providing feedback and information, developing healthy coping mechanisms, and facilitating access to resources and material goods that support activity.56
Social ties may also impact physical activity levels through provision of social support and development of social norms that support or constrain physical activity,9,12
although these factors were not significant predictors of pedometer-measured physical activity in this study. Future research should continue to investigate mediating mechanisms for this association. In addition, our measure of personal social network focused on 1 aspect of social networks (size). Future studies should also examine other characteristics of the social ties (e.g., quality of relationships), including aspects of networks themselves (e.g., homogeneity, density).
Although less striking in magnitude, we also found that residents with conflicting demands had higher levels of pedometer-measured activity, taking on average nearly 600 more steps per day. This finding is similar to that of Emmons et al., who found that having competing role demands was associated with self-reported physical activity among a sample of working-class, multiethnic adults.19
These findings are in contrast to previous population-based studies reporting that caregiving duties may serve as a barrier to physical activity participation, particularly among women.18,57
Among our sample, residents with conflicting demands on their daily activities may have been those who work multiple jobs or have stressful responsibilities and, therefore, have more sources of physical activity (e.g., occupational, transportation, domestic), that would be captured by a pedometer. More research is needed to understand the influence of competing demands on physical activity, as well as other health behaviors and outcomes, including indicators of mental health.
Interestingly we did not find a multivariable association between some of the other social factors and physical activity. Because of efforts to reduce survey respondent burden, several measures were adapted, which may have contributed to limited variability of responses and null associations. Alternatively, this limitation may suggest that the social determinants of physical activity differ across populations and contexts, and that other factors (e.g., poverty, inadequate resources, limited access to or time for physical activity, cultural norms) are more important in understanding physical activity among residents of low-income housing. In addition, steps per day may be largely nonpurposeful in this population, and accumulated through transportation and occupational activities, so some social factors may have less influence on their physical activity. Although not explored here, it is also important to recognize and investigate the negative functional aspects of social factors,9,12,58
which may include obligation, coercion, and the modeling and reinforcement of unhealthful social norms. Research should continue to explore these associations among this population to help disentangle these substantive and methodological issues.
Limitations and Strengths
These findings should be considered in light of study limitations, including the cross-sectional nature of analyses. The response rate for this study was lower than hoped, but it was consistent with that of other community-based studies.59,60
Furthermore, findings are only generalizable to ambulatory residents of urban, lower-income housing in the United States, a population that is predominantly female. We used several adapted measures of social factors (to reduce respondent burden) that may have contributed to null findings for some of the social variables. In addition, the measures we used to capture social factors were individual-level measures that capture perceptions of the social environment. Although perceptions are important in shaping behavior, researchers may consider using network or neighborhood-level measures of social factors to capture different aspects of the social environment that may have implications for health among this population, including aspects of the built environment (e.g., access to recreational facilities, walkability of sidewalks, land-use patterns).61,62
Finally, we cannot determine from our findings the type or source of physical activity of our participants. In light of the sociocultural context of low-income housing and the nature of the sample (low-income), we suspect it was accumulated through activities of daily living, in keeping with recommendations from the active living literature.63,64
Furthermore, the approaches used here for measuring physical activity are valid and reliable strategies for measuring physical activity. Pedometer-measured activity has been recommended for measuring steps accumulated through nonleisure activities,47,65,66
including walking, a common source of activity among lower-income populations.
This research also has several important strengths. This investigation was conducted among a large, systematically sampled, racially and ethnically diverse sample. These findings contribute to the small but growing literature on social determinants of physical activity among lower-income populations. Although we had limited degrees of freedom, we controlled for a number of potentially confounding variables in our analyses, including important environmental factors such as safety. Research suggests that physical activity tied to transportation, domestic, and occupational activities (including walking) may be more common among low-income populations and some racial/ethnic minority groups,6,47,67,68
However, these forms of activity are least reliably recalled. Thus, pedometer-assessed physical activity levels in such a large, diverse, and low-income cohort is a significant contribution of the present study.
This study enhances understanding of how the social environment contributes to differences in physical activity and reinforces that, although individual-level factors are clearly important, physical activity is shaped by multiple levels of influence. Taken together, this growing literature suggests that social factors should be considered when determinants of physical activity are studied, and that physical activity interventions among lower-income populations should address multiple levels, including the social network level and other aspects of social context.