Mental fatigue increases perception of effort but does not compromise the inhibitory control of football referees during a match simulation physical task

Executive functioning (EF) in referees is associated with their decision-making during a match and can be affected by mental fatigue (MF), a psychobiological state induced by prolonged periods of cognitive activity or high cognitive demand within a short timeframe. Therefore, the aim of this study was to investigate the impact of MF on EF and the perception of effort during a physical task for football referees. Twelve male professional football referees were recruited (32 ± 7.3 years; 1.75 ± 0.06 cm; 85 ± 13.32 kg; 41.4 ± 5.92 mL kg^-1 min^-1 VO2max), visiting the laboratory on three occasions: one for characterization and familiarization and two experimental manipulations: high cognitive load (MF) and low cognitive load. After manipulations, they performed a physical task designed to replicate the physical demands of an official match. During the physical task, executive functioning was tested with a reaction time task and the ratings of perceived effort were assessed using subjective scales. The results revealed no effect of MF on response time performance (p = 0.395). However, higher perceptions of effort were observed in the high cognitive load condition (p = 0.018), which may impact physical performance. Despite the alteration in the perception of effort due to mental fatigue, executive function performance of football referees remained unimpaired.