How does ICAO define fatigue?

ICAO defines fatigue as a physiological state of reduced performance capability, which encompasses both physical and mental aspects. This definition highlights that fatigue can compromise an individual's ability to perform tasks effectively due to diminished energy levels and impaired cognitive functioning. Understanding fatigue in this context is crucial, especially in aviation and other high-stakes environments, because it emphasizes the necessity of recognizing when one's performance may be impacted, thereby ensuring safety and operational effectiveness. This definition sets it apart from other potential interpretations, which may focus on aspects like exercise or alertness, without capturing the comprehensive nature of how fatigue affects performance.