CDL Class A Practice Test 2026 - Free CDL Class A Practice Questions and Study Guide

Frequent yawning is a notable sign of sleep debt. It typically indicates that the body is signaling a need for rest and is often a reflexive response to drowsiness and fatigue. When someone is sleep-deprived, their body struggles to maintain alertness, leading to increased yawning as a way to help regulate oxygen levels and promote wakefulness.

In contrast, feeling energetic or experiencing increased focus and better decision-making are generally associated with adequate rest rather than sleep debt. These conditions are indicative of being well-rested and alert, which stands in stark contrast to the fatigue and lethargy resulting from insufficient sleep.