Reliability and Validity of a Questionnaire for Assessing Self-Perceived Health-Related Fitness in Spanish Children.

There is a need for developing tools aimed at assessing fitness in children, due to its relationship with health. This study is aimed at testing the reliability and the validity of a questionnaire designed for assessing self-perceived health-related fitness in Spanish children. The questionnaire was created based on the model of physical self-concept developed by Fox and Corbin (1989) who conceived four sub-domains: Sport competence, attractive body, strength and physical condition. A total of 283 children (mean age: 10.80 ± 0.69 years; 45.6% girls) answered the questionnaire twice, in order to determine its test-retest reliability. The results obtained in the International Fitness Scale (IFIS) and on a fitness battery were used to determine its validity evidence based on relations to other variables. Exploratory and factorial analyses were performed to check its validity evidence based on internal structure. The obtained results indicated that the questionnaire showed an accurate validity evidence based on internal structure and a very good test-retest reliability, Intraclass correlation coefficient: .88; 95% CI [.84, .90]. The questionnaire established moderate correlations with the IFIS questionnaire (ρ = -.51 to -.68) and the fitness level showed by the children (ρ = -.53). These findings indicate that the questionnaire can be a useful research tool for assessing self-perceived health-related fitness in children.