The Relationship Between Aspects of Friendship Networks and Physical Activity and Sedentary Behaviour Among Youth

Physical inactivity and sedentary behaviour are two health-risk behaviours that are impacting the health and well-being of Canadian youth. Further investigation into the social determinants of these behaviours, specifically aspects of friendship networks, could provide an additional layer of understanding on the social mechanisms behind patterns of physical activity and sedentary behaviour among youth. The aim of this thesis was to examine the associations between aspects of friendship networks and physical activity and sedentary behaviour among youth through a review of current literature and through an analysis of social network and behavioural survey data. The purpose of the literature review was to provide a synthesis and assessment of current evidence on friendship networks and physical activity and sedentary behaviour. The purpose of the survey data analysis was to expand the breadth of social network-derived variables so as to provide an additional level of understanding regarding the associations between aspects of friendship networks and physical activity and sedentary behaviour. The systematized literature review involved a search of peer-reviewed articles that included a measure of a child or adolescent’s social network (e.g., close friends) or network position (e.g., popularity) as well as a measure of physical activity and/or sedentary behaviour. Results from this review suggested that best friend’s and close friends’ physical activity levels were consistently associated with an individual’s physical activity level. Longitudinal evidence showed, over time, that an individual’s level of physical activity changed to reflect his or her friends’ level of physical activity. Adolescents with more friendship nominations were also more physically active, and friends’ physical activity was more often associated with boys’ physical activity compared with girls’ physical activity. Evidence on sedentary behaviour was mixed. The survey analysis included data from 1,061 adolescents from six Calgary Catholic schools (Alberta, Canada), and examined cross-sectional associations between aspects of friendship networks (i.e., friendship network density, proportion of active close friends, proportion of sedentary close friends, betweenness centrality, popularity, clique member) and likelihood of being sufficiently active (i.e., achieving at least sixty-minutes of moderate-to-vigorous physical activity (MVPA) every day), as well as likelihood of being highly sedentary (i.e., more than two-hours per day of sedentary behaviour), while controlling for sociodemographic variables and general perceived social support from friends. Potential effect modification of perceived general social support from friends and social network variables was also tested. Results suggested that both boys and girls with a higher proportion of sufficiently active close friends were more likely to be sufficiently active. Adolescents who received no friendship nominations participated in fewer days per week of MVPA compared with adolescents who had at least one friendship nomination. Higher levels of perceived social support from friends modified the effects of social network variables and the likelihood of being sufficiently active and highly sedentary. Higher friendship network density was associated with an increased likelihood of being highly sedentary for boys compared with low friendship network density. Evidence from this thesis provides support for the presence of associations between aspects of friendship networks (i.e., friends’ behaviour, popularity, receiving no friendship nominations) and an individual’s physical activity. Network structure (i.e., friendship network density) may also be associated with boys’ sedentary behaviour. Associations between aspects of friendship networks and physical activity have been identified for both boys and girls; however, associations with sedentary behaviour may be gender-specific. These results can inform future public health interventions focused on network restructuring to promote co-participation and friendship modeling to harness the impact of friendship influence with the goal of increasing levels of physical activity and reducing time spent participating in sedentary behaviour among Canadian youth

Associations between Aspects of Friendship Networks, Physical Activity, and Sedentary Behaviour among Adolescents

Background. Adolescent friendships have been linked to physical activity levels; however, network characteristics have not been broadly examined. Method. In a cross-sectional analysis of 1061 adolescents (11–15 years), achieving 60 minutes/day of moderate-to-vigorous physical activity (MVPA) and participating in over 2 hours/day of sedentary behaviour were determined based on friendship network characteristics (density; proportion of active/sedentary friends; betweenness centrality; popularity; clique membership) and perceived social support. Results. Adolescents with no friendship nominations participated in less MVPA. For boys and girls, a ten percent point increase in active friends was positively associated with achievement of 60 minutes/day of MVPA (OR 1.11; 95% CI 1.02–1.21, OR 1.14; 95% CI 1.02–1.27, resp.). For boys, higher social support from friends was negatively associated with achieving 60 minutes/day of MVPA (OR 0.63; 95% CI 0.42–0.96). Compared with low density networks, boys in higher density networks were more likely to participate in over 2 hours/day of sedentary behaviour (OR 2.93; 95% CI 1.32–6.49). Social support from friends also modified associations between network characteristics and MVPA and sedentary behaviour. Conclusion. Different network characteristics appeared to have different consequences. The proportion of active close friends was associated with MVPA, while network density was associated with sedentary behaviour. This poses challenges for intervention design.Peer Reviewe

Associations between Aspects of Friendship Networks, Physical Activity, and Sedentary Behaviour among Adolescents

Background. Adolescent friendships have been linked to physical activity levels; however, network characteristics have not been broadly examined. Method. In a cross-sectional analysis of 1061 adolescents (11–15 years), achieving 60 minutes/day of moderate-to-vigorous physical activity (MVPA) and participating in over 2 hours/day of sedentary behaviour were determined based on friendship network characteristics (density; proportion of active/sedentary friends; betweenness centrality; popularity; clique membership) and perceived social support. Results. Adolescents with no friendship nominations participated in less MVPA. For boys and girls, a ten percent point increase in active friends was positively associated with achievement of 60 minutes/day of MVPA (OR 1.11; 95% CI 1.02–1.21, OR 1.14; 95% CI 1.02–1.27, resp.). For boys, higher social support from friends was negatively associated with achieving 60 minutes/day of MVPA (OR 0.63; 95% CI 0.42–0.96). Compared with low density networks, boys in higher density networks were more likely to participate in over 2 hours/day of sedentary behaviour (OR 2.93; 95% CI 1.32–6.49). Social support from friends also modified associations between network characteristics and MVPA and sedentary behaviour. Conclusion. Different network characteristics appeared to have different consequences. The proportion of active close friends was associated with MVPA, while network density was associated with sedentary behaviour. This poses challenges for intervention design