Daily relations between social perceptions and physical activity among college women

Objectives: There is a need to develop more effective physical activity (PA) promotion programs for college women. Theory and evidence suggest that perceptions of the social environment play a role in college women's PA, though little is known about how these perceptions are associated with PA at the day level. The goal of this study was to examine relations between changes in college women's daily social perceptions and objectively assessed PA over seven days. Design: Daily diary method. Method: College women (n = 80, M_Age = 20, M_BMI = 23.1 kg/m²) wore Fitbit wristbands and completed daily self-reports of (1) the quantity and perceived intensity of their social interactions (positive/negative), and (2) the occurrence of social comparisons (based on appearance/health/status) for seven days. Results: Multilevel models showed daily variability in predictors and outcomes (ps < 0.0001), as well as relations between within-person changes in social perceptions and PA. Increases in negative interactions (particularly those with friends) were consistently associated with decreases in daily PA, whereas increases in positive interactions showed limited relations (srs = −0.22-0.34). Days with health comparisons were days with greater PA for women who had stronger overall interest in comparisons, but were days with less PA for women with weaker overall interest (srs = 0.22–0.33). PA did not differ between days with vs. without appearance comparisons. Conclusions: Social perceptions show meaningful day-to-day variability and relations with college women's daily PA, and specific associations may be useful for improving tailored interventions for college women.