CC BY 4.0 DEED Attribution 4.0 InternationalMcEwan, GaryUnnithan, Viswanath B.Easton, ChrisGlover, Andrew J.Arthur, Rosie2024-02-232024-02-232024-03-18McEwan, G.P., Unnithan, V.B., Easton, C., Glover, A.J. and Arthur, R. (2024) ‘Decision‐making accuracy of soccer referees in relation to markers of internal and external load’, European Journal of Sport Science, 24(6), pp. 659–669. Available at: https://doi.org/10.1002/ejsc.12096.https://eresearch.qmu.ac.uk/handle/20.500.12289/13682https://doi.org/10.1002/ejsc.12096Rosie Arthur - ORCID: 0000-0003-0651-4056 https://orcid.org/0000-0003-0651-4056Supplementary data for this paper is available at: https://eresearch.qmu.ac.uk/handle/20.500.12289/13683 .AM replaced with VoR 2024-03-18.This study examined the relationships between the decision-making performances of soccer referees and markers of physiological load. Following baseline measurements and habituation procedures, 13 national-level male referees completed a novel Soccer Referee Simulation (SRS) whilst simultaneously adjudicating on a series of video-based decision-making clips. The correctness of each decision was assessed in relation to the mean heart rate (HR), respiratory rate (RR), minute ventilation (V̇E), perceptions of breathlessness (RPE-B) and local muscular (RPE-M) exertion, and running speeds recorded in the 10-s and 60-s preceding decisions. There was a significant association between decision-making accuracy and the mean HR (P=0.042; VC=0.272) and RR (P=0.024, VC=0.239) in the 10-s preceding decisions, with significantly more errors observed when HR ≥90% of HRmax (OR, 5.39) and RR ≥80% of RRpeak (OR, 3.34). Decision-making accuracy was also significantly associated with the mean running speeds performed in the 10-s (P=0.003; VC=0.320) and 60-s (P=0.016; VC=0.253) preceding decisions, with workloads of ≥250 m·min-1 associated with an increased occurrence of decisional errors (OR, 3.84). Finally, there was a significant association between decision-making accuracy and RPE-B (P=0.021; VC=0.287), with a disproportionate number of errors occurring when RPE-B was rated as “very strong” to “maximal” (OR, 7.19). Collectively, the current data offer novel insights into the detrimental effects that high workloads may have upon the decision-making performances of soccer referees. Such information may be useful in designing combined physical and decision-making training programmes that prepare soccer referees for the periods of match play that prove most problematic to their decision-making.659–669en© 2024 The Authors. European Journal of Sport Science published by Wiley-VCH GmbH on behalf of European College of Sport Science. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.http://creativecommons.org/licenses/by/4.0/Team SportPhysiologyPerformanceAssessmentCognitionArticle