The idea of training your body to need less sleep is appealing, especially in a world that values productivity and long hours. Many people wonder if it is possible to condition themselves to thrive on fewer hours of rest without sacrificing health or performance. While the human body is highly adaptable in many ways, sleep science shows that reducing sleep needs is not something we can truly train ourselves to achieve.
Sleep is a biological necessity, not just a habit. According to the Centers for Disease Control and Prevention, adults need at least seven hours of sleep per night for optimal health. Research published in Sleep journal has shown that chronic sleep restriction impairs cognitive performance, memory, reaction time, and mood, even when individuals believe they are adapting to shorter sleep schedules. In reality, the body accumulates a sleep debt that eventually takes a toll on mental and physical health.
One of the key misunderstandings is the difference between feeling accustomed to less sleep and actually needing less sleep. Studies conducted at the University of Pennsylvania found that participants restricted to six hours of sleep per night over two weeks performed as poorly on cognitive tasks as those who had been completely sleep deprived for two nights in a row. The participants often reported feeling only mildly tired, but testing revealed a significant decline in alertness and accuracy. This shows that the body cannot be trained to truly reduce its sleep requirement, though it may adjust to functioning at a lower level without obvious warning signs.
There are rare exceptions due to genetics. Research led by Dr. Ying-Hui Fu at the University of California, San Francisco, identified genetic mutations in people known as “natural short sleepers” who thrive on four to six hours of sleep per night without the typical health risks. However, these individuals represent a very small portion of the population. For most people, attempting to train the body to need less sleep only results in increased risk of conditions such as cardiovascular disease, diabetes, weakened immunity, obesity, and cognitive decline, as shown in studies published in Nature and Science of Sleep.
What people can do is improve sleep efficiency rather than reduce the need for sleep. Good sleep hygiene practices such as maintaining a regular bedtime, limiting screen exposure before bed, avoiding caffeine late in the day, and creating a restful environment can help maximize the quality of sleep. This ensures that the hours spent sleeping are restorative and effective, which may reduce feelings of fatigue during the day. But this is not the same as lowering the body’s sleep requirement.
The takeaway is that while the idea of training the body to need less sleep is tempting, it is largely a myth. With rare genetic exceptions, humans cannot significantly alter their biological sleep needs. Instead of focusing on cutting down sleep time, prioritizing high-quality rest is the key to sustaining energy, productivity, and long-term health.
Disclaimer: This article is for informational purposes only and should not be taken as medical advice. If you are experiencing ongoing sleep difficulties or extreme fatigue, consult with a healthcare provider for evaluation and guidance.
References:
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Centers for Disease Control and Prevention. (2022). How much sleep do I need? Retrieved from https://www.cdc.gov
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Van Dongen, H. P. A., Maislin, G., Mullington, J. M., & Dinges, D. F. (2003). The cumulative cost of additional wakefulness: Dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep, 26(2), 117–126.
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Fu, Y. H., Xu, Y., Garfinkel, M., & Ptáček, L. J. (2019). Short sleep: Genetic basis and clinical implications. Nature and Science of Sleep, 11, 111–118.
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Dinges, D. F., & Banks, S. (2009). Sleep and circadian rhythms. In Fundamental Neuroscience (pp. 159–173). Academic Press.
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Goel, N., Basner, M., Rao, H., & Dinges, D. F. (2013). Circadian rhythms, sleep deprivation, and human performance. Progress in Molecular Biology and Translational Science, 119, 155–190.