Multidimensional assessment of breathlessness during exercise: current methods and recommendations.

Dyspnea, or breathlessness, is a complex, multidimensional symptom of breathing discomfort, which significantly impacts quality of life and clinical prognosis. While traditional assessments have primarily focused on breathlessness sensory intensity, this approach does not consider affective and/or qualitative dimensions. Growing evidence highlights the need for multidimensional assessment approaches that provide a more comprehensive understanding of breathlessness, particularly in the context of exercise. Cardiopulmonary exercise testing (CPET) provides a standardized physiological stimulus to assess breathlessness responses in real-time, offering valuable insights into its underlying mechanisms and response to therapeutic intervention. Normative reference equations can help identify abnormally high breathlessness intensity during CPET. This review examines current methodologies for multidimensional breathlessness assessment during exercise, including single-item rating scales, multidimensional tools, descriptor lists, and locus of symptom limitation. We also discuss best practices for linking breathlessness with physiological responses during CPET to enhance mechanistic understanding, inform targeted interventions, and evaluate interventional efficacy. Standardizing assessment approaches and ensuring transparent reporting are critical steps toward improving the clinical and research utility of exertional breathlessness assessments.