Neurophysiological measures of exercise-induced fatigue in athletes: a scoping review protocol

OBJECTIVE: This scoping review will map the existing literature on neurophysiological measures used to assess exercise-induced fatigue in athletes. INTRODUCTION: Exercise-induced fatigue, defined as a transient reduction in physical performance resulting from central and peripheral mechanisms, is a critical factor influencing training adaptation, recovery, and injury risk in athletes. Traditional monitoring tools often lack precision or ecological validity. Neurophysiological approaches, including autonomic, central, and peripheral measures, offer objective means of quantifying fatigue. However, evidence in athletic populations remains scattered, with inconsistent methods and limited integration across measurement domains. ELIGIBILITY CRITERIA: This review will consider quantitative studies involving trained adult athletes (18-35 years old) from any sporting discipline who report neurophysiological outcomes following a defined fatigue-inducing protocol. Studies focusing exclusively on clinical, untrained populations or those lacking neurophysiological measures will be excluded. METHODS: This review will follow the JBI methodology for scoping reviews and will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Searches will be conducted in PubMed, CINAHL (EBSCOhost), SPORTDiscus (EBSCOhost), Scopus, Web of Science Core Collection, and ProQuest Dissertations and Theses Global (ProQuest Central), which also serves as a source of gray literature. Studies meeting the eligibility criteria will be screened and charted using a piloted extraction tool. Data will be synthesized narratively and visually through tables, figures, and heat maps organized by neurophysiological domain, fatigue protocol, and analytical approach. REVIEW REGISTRATION: OSF https://osf.io/kwnjp/.