Applications of muscle oxygen saturation analysis in cycling performance assessment: a systematic review

Purposeː Cycling performance is the results of the interplay among a wide range of variables. Different methodological approaches have been described during last 50 years in order to evaluate and understand cycling performance. Our main aim was to systematically review the applications of muscle oximetry in cycling performance assessment. Methods: A structured search was carried out following the PRISMA guidelines in MEDLINE®/PubMed and Scopus databases were searched with additional integration from external sources, between 1 February and 31 March 2020. To meet the inclusion criteria studies published from 2000 to 2020 and that applied muscle oxygen saturation analysis to investigate cyclists’ performance were selected. This review included studies with experimental designs. There were no filters applied to the cyclists’ level, sex, ray or age. Results: Starting from the 955 identified records, 21 items were finally included for the review. Three main investigation topics, related to application of muscle oximetry in cycling science, emerged: cycling performance analysis protocols (n=8); training response and adaptations evaluation (n=8) and impact of different pedaling cadences on cycling performance (n=6). From the studies analyzing performance assessment protocols (38%), emerged how only one threshold, also named breakpoint, seems to be recognizable through NIRS during cycling tests. Studies that focused on training metabolic adaptations (38%) and cadence analysis (25.6%) evidenced how NIRS device may represent a valid tool to analyze cyclists’ metabolic adaptations and optimize pedaling cadence strategy. Conclusionː Despite the wide range of applications and promising data emerging from NIRS studies, further investigations evaluating cycling performance are needed to better delineate possible, laboratory and field, applications, and methodologies