Extensive research demonstrates the importance of the social environment for physical activity (PA) among African American (AA) women. Such studies rarely evaluate the simultaneous impact of interpersonal factors across multiple systems or fluctuations across time. This study used Ecological Momentary Assessment (EMA) within a group-based PA intervention to evaluate how interpersonal factors impacted daily PA. Data were collected from 45 AA women (Mage = 52.7 ± 14) in the Together Everyone Achieves More Physical Activity randomized controlled trial. Participants used a smartphone-based EMA application and received two daily prompts across three 7-day phases of the intervention period while simultaneously wearing a Fitbit. Participants answered questions about interpersonal factors within their intervention group (social support given and received, relatedness, collective efficacy, and group cohesion) and external social support. Participants engaged in greater steps on days with higher than usual external social support (relative to one's usual level) (B = 535.25, P <.001) and higher than usual social support given to others in the intervention group (B = 673.10, P = .003). Participants were more likely to engage in any moderate to vigorous PA (MVPA) on days with higher than usual social support received from the intervention group (OR = 1.59, P = .014) and engaged in greater overall MVPA on days with higher than usual external social support (B = 0.18, p <.001). By evaluating within-person changes over time and with a systems-level focus, this study provides novel insights into the role of interpersonal support for promoting PA among AA women.
Sweeney et al. (Sat,) studied this question.