Abstract
OBJECTIVES: Mental and physical fatigue may impair basketball players' attentional focus and performance, but experimental evidence is limited. Thus, the objective was to systematically review studies on the acute effects of mental and/or physical fatigue on attentional focus, visual search/quiet eye behavior, and performance in basketball tasks. METHODS: Following PRISMA 2020, we searched PubMed, Scopus and Web of Science. Eligible studies experimentally manipulated fatigue in basketball players and assessed attentional focus (i.e., internal-external focus instructions/self-reported focus, and visual-attentional control indexed by gaze/quiet eye and visual search metrics) and basketball-specific performance (decision-making accuracy/response time and shooting outcomes). Two authors screened records, extracted data, and assessed risk of bias. Because of the small number of included studies, heterogeneity and incomplete reporting, findings were synthesized narratively and individual study effect sizes were interpreted descriptively rather than pooled. RESULTS: Out of 492 records, five studies (n = 89 male players) were included, two on mental fatigue and three on physical fatigue, and no eligible study included female athletes, limiting generalizability to women's basketball. Mental-fatigue protocols using a basketball videogame consistently impaired video-based decision-making and altered visual search; one study showed that anodal transcranial direct current stimulation attenuated these effects. Moderate physical fatigue showed inconsistent or trivial effects on shooting outcomes, whereas severe physical fatigue reduced free-throw accuracy and quiet eye duration, while external attentional focus partially protected shooting performance. All studies showed at least "some concerns" or higher risk of bias. CONCLUSION: Preliminary evidence suggests that both mental and physical fatigue disrupt attentional focus and can impair basketball performance. Larger, preregistered, and more ecologically valid trials are required. Registration: OSF (osf.io/6hz9p). SYSTEMATIC REVIEW REGISTRATION: https://doi.org/10.17605/OSF.IO/Z4F2N, identifier osfio/z42n.