POWERbreathe® S-Index Test – guidelines and recommendations for practitioners

: POWERbreathe® S-Index Test is an accessible and functional evaluation of inspiratory muscle strength. The main purpose of this study is to present guidelines that allow to successfully apply the test in sports settings with high accuracy, robustness, and repeatability. : Review of available literature and professional guidelines regarding traditional spirometry testing and POWERbreathe® trainers’ application was performed. The obtained information was summarized, analyzed, and interpreted to create POWERbreathe® S-Index Test guidelines and recommendations for practitioners. POWERbreathe® K4 and K5 (POWERbreathe International Ltd., Southam, UK) devices paired with Breathe-Link Live Feedback Software (POWERbreathe International Ltd., Southam, UK) were considered during the analysis and guidelines creation. : We recommend performing POWERbreathe® S-Index Test with 8 forceful and dynamic inspiratory maneuvers from residual volume to full inspiratory capacity, divided into 2–3 series of 2–3 maneuvers, in a standing position, after respiratory warm-up. : POWERbreathe® S-Index Test may be a useful tool to measure functional inspiratory muscle strength in athletes. When performed with the presented guidelines, it can be successfully applied in sports settings with high accuracy, robustness, and repeatability.