Which of the following is not a sign of acute fatigue?

Acute fatigue is characterized by a range of signs that indicate a decrease in physical or mental performance due to exhaustion. Sluggishness, overconfidence, and poor coordination are all symptoms commonly associated with acute fatigue. Sluggishness refers to a lack of energy or vitality, whereas poor coordination can occur as the nervous system's efficiency declines. Overconfidence in this context can manifest when individuals misperceive their abilities due to fatigue, leading them to undertake tasks beyond their actual capacity.

On the other hand, excessive alertness is not a sign of acute fatigue. In fact, it often indicates the opposite: a heightened state of awareness and readiness. When someone is excessively alert, they are typically more responsive and attentive, which contradicts the state of fatigue. Therefore, identifying excessive alertness as not being a characteristic of acute fatigue is appropriate, as it suggests a level of cognitive or physical readiness that acute fatigue does not present.