Background: Mental fatigue is a psychophysiological state that can impair cognitive, technical, tactical, and physical performance in football. Despite growing interest in this topic, there is currently no standardized approach for assessing and monitoring mental fatigue in football contexts. This systematic review aimed to (i) synthesize the evidence regarding the effects of mental fatigue on football performance and (ii) identify the methodologies currently used to induce, detect, and analyze mental fatigue in football. Methods: Following PRISMA 2020 guidelines, a systematic search was conducted in the PubMed, Web of Science, SportDiscus, Scopus, and Springer Nature Link. Studies published between 1 January 2014 and 15 May 2026 in English, Portuguese, Spanish or French were included. Methodological quality was assessed using the Mixed Methods Appraisal Tool. Twenty-eight studies met the eligibility criteria. Results: The findings showed that mental fatigue generally impairs football performance, particularly decision-making, technical execution, tactical behavior, attention, and perceived exertion. However, the magnitude and consistency of these effects varied according to the type of performance outcome assessed and the methodological approaches used across studies. Subjective assessment tools, such as visual analogue scales and perceived workload measures, were the most commonly used methods, whereas objective approaches, including eye-tracking systems, functional near-infrared spectroscopy, and psychomotor vigilance tests, were less frequently applied. Overall, substantial methodological heterogeneity and the absence of standardized assessment protocols limited comparisons between studies and reduced the practical app licability of findings. Conclusion: Current evidence suggests that mental fatigue negatively affects multiple dimensions of football performance, although methodological inconsistencies remain substantial. There is a clear need for standardized, ecologically valid assessment and monitoring protocols integrating both subjective and objective measures to improve performance management and recovery strategies in football.
© Copyright 2026 Frontiers in Sports and Active Living. Frontiers Media. Alle Rechte vorbehalten.