Background:
Physical activity (PA) plays an important role in the prevention and treatment of overweight and obesity. Understanding the correlates of PA is typically deemed to be an important first step in identifying factors that are possible mediators of PA and subsequently may be targeted for change. According to the ecological model, PA behaviour is explained by the interaction between the individual and the environment. Self-efficacy towards PA has shown to be an important personal determinant of PA in adults as well as in children. Many studies have demonstrated that there is a link between certain environmental factors and PA in adults, but different environmental variables are likely to be operating for children or adolescents. There is an urgent need for more research into environmental determinants of PA in younger people. In addition, studies investigating the link between environmental factors and PA are scarce in Europe. Since environmental variables in US, Canada and Australia significantly differ from the European context, investigating critical environmental factors in Belgian youth might provide an excellent contribution to international literature. Finally, to our knowledge, no studies have examined the moderating effect of self-efficacy on the relationship between social and physical environmental factors and level of PA in young people.
Objectives:
This study examined differences in level of PA and environmental correlates of PA between youngsters with high versus low self-efficacy (SE) towards PA. It further explored whether the prediction of PA by social and physical environmental factors is different in youngsters with high versus low SE towards PA.
Methods:
1448 youngsters (17.4±0.6 yrs-old, 43.5% boys, 21.8±2.9 kg/m²) were recruited in 20 randomly selected schools in Flanders. Level of PA, psychosocial and environmental correlates of PA were assessed using validated questionnaires (Flemish Physical Activity Questionnaire and Dutch version of the NEWS Questionnaire). The total sample was divided into youngsters with low (N= 451) versus high (N= 923) SE towards PA. Independent Samples t-tests were used to investigate differences in PA and environmental correlates of PA between both groups. To predict PA from social and physical environmental factors, multiple regression analyses were executed separately in youngsters with low and high SE towards PA.
Results:
Youngsters with low SE towards PA reported 43 fewer minutes of total PA per day compared to peers with high SE (p<.001). Amount of active transport was higher in youngsters with high SE (60±36 min/day) compared to youngsters with low SE (46±29 min/day) (p<.001), whereas sport participation was almost double in youngsters with high SE (62±40 min/day versus 32±26 min/day) (p<.001). There were small but statistically significant differences in perceived physical and social environmental factors between both groups. Youngsters with low SE towards PA perceived their environment as less supportive to be active compared to youngsters with high SE: they reported greater walking distances to neighbourhood facilities (shops, restaurants, pubs, recreational facilities) (p=.01), lower neighbourhood bikability (p=.001), lower neighbourhood safety from traffic (p<.05), lower availability of sport equipment at home (p<.001), lower accessibility of sport facilities (p<.05), lower emotional satisfaction with neighbourhood (p<.001), lower modeling, social norm and social support of friends and family (p<.001) and bad weather kept them more from being active (p<.001). In youngsters with low SE towards PA, 11% of the variance in total PA was explained by environmental factors (p<.001), whereas in youngsters with high SE towards PA environmental factors explained 16% of the variance in total PA (p<.001). In youngsters with low SE towards PA significant predictors of PA were: neighbourhood walkability (p<.05), safety from traffic (p=.05), weather (p<.001), modeling of family (p<.01) and social support of friends (p<.01). In youngsters with high SE towards PA significant predictors of PA were: connectivity (p=.01), aesthetics (p<.05), safety from traffic (p<.05), weather (p<.001), accessibility of sport facilities (p=.05), modeling of family (p=.01) and friends (p=.01) and social support of friends (p<.001). In both groups weather and social support of friends were the most important predictors.
Conclusions:
We can conclude that youngsters with low SE towards PA have much lower PA levels compared to peers with high SE. Youngsters with low SE towards PA also reported slightly lower social and physical environmental correlates of PA. Four environmental predictors of PA were the same for both groups, with weather and social support being the most important correlates of PA. Walkability was the only specific predictor of PA in youngsters with low SE towards PA, whereas connectivity, aesthetics, accessibility of sport facilities, modeling of friends were the only significant predictors in youngsters with high SE. The results of this study show that slightly different social and physical environmental factors are important in youngsters with high versus low SE towards PA. This information might be useful to guide intervention strategies in future.
Support:
Support for this study was provided by the post-doctoral fellowship of the Research Foundation - Flanders (FWO) of the first author.
