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.
Alex’s Notes: It’s good advice to choose your friends wisely, because who they are is what you are perceived to be. The aim of this study was twofold:
- To examine the associations between aspects of school-based friendship networks (i.e., friendship network density, friend behavior, popularity, and network roles), general perceived social support from friends, and achievement of recommended levels of physical activity and sedentary behavior for adolescent boys and girls
- To examine the extent to which general perceived social support from friends modifies associations between friendship network measures and physical activity and sedentary behavior.
To explore the above associations, the researchers approached several schools in Alberta, Canada to see if they would be interested in participating. Six schools agreed and a total of 1,061 boys and girls ranging from 11-15 years of age were provide a number of surveys to fill out regarding physical activity, sedentary behavior, general perceived social support from friends, and sociodemographic characteristics, and within-grade friendship network.
Most the survey results were dichotomized into two categories. Physical activity was divided between achieving at least 60 minutes of moderate-to-vigorous physical activity (MVPA) on six or fewer days per week (insufficiently active), or all seven days per week (sufficient active). Sedentary behavior included watching television, using a computer, or playing video games outside of school and was similarly dichotomized into low-sedentary and high-sedentary with the cut-off point being two hours per day. The social network variables were the most interesting. In addition to completing a social support scale consisting of four items (how often they had friends who tried to help them; they could count on when things go wrong; they could share happy and sad times; and they could talk to about problems), the kids were presented with a list of all individuals enrolled in their grade and were asked to indicate their closest friends.
A higher percentage of boys (16%) were sufficiently active compared with girls (7.3%), while participation in at least two hours of sedentary activity per day was similar between both genders at just fewer than 80%. Wow, that is some discouraging results! Note that these values are the sum of weekly activity divided by seven days, so being really active one day and not the next could still average out to being sufficiently active. Obviously this wasn’t the case for most, however.
The number of incoming closest friend nominations averaged 6-7, which means that on average 6-7 other students chose another student as a good friend when presented the aforementioned list of kids enrolled in their grade. Unfortunately, 21 kids received no nominationsL. Sad faces aside; all 21 of those children were insufficiently active and spent significantly fewer days per week engaged in at least 60 minutes of MVPA than children who received one nomination.
For everyone else, excluding those with no friendship nominations and adjusting for all covariates,a higher proportion of active close friends (every 10% increase) were associated with an increased likelihood (11% for boys and 14% for girls) of achieving sufficient levels of physical activity. Interestingly, boys with a higher general perceived social support from friends were significantly less likely (37%) to be sufficiently active. So having close friends who are active appears beneficial; but this is a two-way street, and not being nominated as a close friend may have a negative impact on physical activity behavior. Moreover, boys who were in a higher density network were more likely to be sedentary compared with those in a low density network, and seeing how the majority of boys were sedentary (80%), a higher density network may have allowed for more exposure to normative attitudes and behavior among the boys within the network, which could result in an increased likelihood of an individual being highly sedentary.
So while casual effects cannot be drawn from this study, it does support the notion that there are benefits to friends, with the caveat being that they should be sufficiently active. We tend to mimic our peers and thus it is only prudent we surround ourselves with those who we aspire to be at least in some manner. At least when we were younger I suppose.