Emerging adulthood is a time where emerging adults develop health behaviors that persist throughout the life span (Barnett et al., 2014). However, only 55.4% of emerging adults engage in the recommended amount of physical activity each week (U.S. Department for Health and Human Services, 2013). The current study examined two factors that are associated with physical activity, specifically self-efficacy and social support, in 403 (M age = 19.25, SD = 1.12) emerging adults. Linear regressions indicated that emerging adults who reported higher levels of general self-efficacy (beta = .13, p \u3c .05), domain self-efficacy (beta = .33, p \u3c .05), and support from the entire social network (beta = .50, p \u3c .001) engaged in more physical activity. Support from the entire social network still accounted for a significant portion of the variance in physical activity when accounting for general or domain self-efficacy (beta for support = .48, p \u3c .001 and .30, p \u3c .05, respectively). The differential effects of source of support (i.e., family and friends) and type of support (i.e., esteem support, informational support, and companionship support) were also examined. Emerging adults who reported higher levels of support from family (beta = .22, p \u3c .001) and friends (beta = .33, p \u3c .001) engaged in more physical activity. Although emerging adults reported receiving more esteem support from family (M = 2.95, SD = 1.23) compared to friends (M = 2.74, SD = 1.15), esteem support from friends (beta = .33, p \u3c .001) had a larger effect on physical activity than esteem support from family (beta = .21, p \u3c .05)
