Structural validity of the Nijmegen questionnaire in physically active young adults

Introduction: Respiratory symptoms are frequently reported by athletes of all abilities and can significantly impact exercise performance and health. The Nijmegen Questionnaire (NQ) has been previously used to identify dysfunctional breathing across several populations, but not among athletes.

Aims and objectives: We aimed to investigate the factor structure of the NQ in a population of recreational athletes and propose a shorter version of the instrument.

Methods: The NQ (n=428) was examined for construct validity through principal components analysis (PCA). Factorability was tested via KMO index and Bartlett's test of sphericity.

Results: Primary evaluation of the data revealed a 'complex structure', therefore four items were excluded from further analysis. PCA revealed three components which we have labelled as in Table 1.