Sleep deprivation does not always manifest through obvious signs like yawning or dark circles; there are subtle signals of sleep deprivation that we do not notice, which means that thinking one functions well on only 4 hours of rest is often an illusion.

noli's read

Shelby Harris's message is based on very solid scientific foundations. A benchmark randomized clinical trial conducted by researcher Hans Van Dongen and his team (published in the journal Sleep in 2003) demonstrated that participants limited to 4 or 6 hours of rest per night experienced a continuous decline in their concentration and attention capabilities, while subjectively reporting that they did not feel that tired as the days progressed. This discrepancy proves that our brain adapts to accumulated fatigue and loses its ability to objectively assess its own drops in performance. The indirect manifestations of this lack of rest—such as irritability, attention issues, or cravings for snacks—are widely confirmed by observational research and expert consensus in chronobiology. While a tiny minority of the population possesses rare genetic traits allowing them to function with a very short amount of rest, this case remains exceptional. For the vast majority, the idea of functioning at one's best with 4 hours of sleep per night is scientifically invalidated.

the sources

1. 1Watson NF et al. (AASM & Sleep Research Society) 2015
2. 2Hirshkowitz M et al. (National Sleep Foundation) 2015