Self-esteem and intentions mediate perceived fitness with physical activity in Finnish adolescents with long-term illness or disabilities

Background: The International Classification of Functioning, Disability and Health (ICF) is recognised as the common language in disability research. However, personal factors in the ICF are not explicitly coded because of cultural differences that influence physical activity (PA) participation. The ICF suggests using fitness as a personal factor, as well as other psychological assets. Intentions may serve as such psychological assets and studies on the antecedents to intentions which prompts PA behaviours is lacking in adolescent long term illness or disability (LTID) populations. Objective: The purpose of this study was to report how ICF personal factors can influence participation in PA. Perceived fitness (FIT), global self-esteem (GSE), and PA intentions (INT) are hypothesised to positively predict PA behaviours among adolescents with LTID after controlling for age. Methods: The data from Finnish 13 and 15 years old adolescents from the self-reported Health Behaviour in School-aged Children study from 2002 and 2010 were pooled. Those with LTID as stated by a medical doctor were included (N = 1,059). Serial mediation with ordinary least squares path analysis was used. Boys and girls were separately analysed, FIT was the independent variable, GSE and INT as mediators, and age controlled moderate-to-vigorous PA (MVPA) the dependent variable. Bias-corrected bootstrap confidence intervals were used to test for significance of the direct and indirect paths. Results: FIT was positively related to GSE and INT for boys and girls. Furthermore, INT were positively related to MVPA for boys and girls. These relationships were statistically significant. Therefore, INT can be seen to mediate the relationship between FIT and MVPA after controlling for age. GSE also acted as a statistically significant mediator for boys, between FIT and INT. Therefore serial mediation was presented with boy's MVPA, whereas in the girl's model, only INT mediated FIT and MVPA. Conclusions: Personal factors influence PA participation in adolescents with LTID. Support for increasing self-esteem for boys seems to be important and it should be taken into account when different PA promotion strategies are planned for boys. Differences in PA between genders suggest overall more promotion of PA for girls is still needed.