Is sleep debt real?

• A. Sleep debt resets after a single night of rest.
• B. Sleep debt is unrelated to fatigue.
• C. Yes, sleep debt builds over time.
• D. Sleep debt is a myth.

Answer: (C)

Sleep debt is real. It means you accumulate a deficit whenever the sleep you get is less than what you need, and this deficit adds up over multiple days. Because of that, a single night of extra sleep can help reduce the debt, but it doesn’t instantly erase several days or weeks of missed sleep; repayment typically takes several nights of adequate rest. This debt is closely tied to fatigue and performance: as it grows, alertness, decision-making, and reaction times tend to decline, which is especially important in aviation. So the best answer recognizes that the deficit builds up over time. The idea that a single night resets it suggests an instant reset, which isn’t accurate; fatigue is indeed related to sleep loss, and the notion that sleep debt is a myth isn’t supported by science.