Dyadic Effects of Individual and Friend on Physical Activity in College Students

Objective: Physical activity (PA) tends to decline throughout the college years, and close friends' influence is known to be an important factor in maintaining PA. This study examined the actor effect and partner effect between an individual and his/her friend regarding the influence of self-efficacy and social support on PA among Korean college students. Design and Sample: Cross-sectional survey data from 108 pairs of individual students and friends were analyzed. Measures: The survey questionnaire measured PA, self-efficacy toward exercise, social support for PA, anxiety and depression, community environments, and perceived health status. Structural equation modeling with path analysis was conducted to test Actor-Partner Interdependence Model (APIM) explaining close relationships on PA. Results: One-sided partner effect that friends' perceived friend support was directly related to individual's PA (b = 0.20, p<.05) was revealed. Regarding actor effects, self-efficacy was directly related to higher levels of PA for individual and friend. Perceived health status was related to higher level of individuals' PA. Conclusions: These results suggest a role for public health nurses in developing interventions for college-aged young adults that promotes friend support for PA as well as individual self-efficacy toward PA, to engage young adults in establishing lifelong health-promoting PA.