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Sustained polyphasic sleep restriction abolishes human growth hormone release.

Yevgenia Rosenblum1, Frederik D Weber1,2, Michael Rak3

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|December 21, 2023
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Summary

Radically polyphasic sleep schedules, with only 2 hours daily, were unsustainable for most participants. Abolished growth hormone release and decreased vigilance suggest these schedules disrupt essential sleep functions.

Keywords:
UbermanEEGREMgrowth hormonepolyphasic sleeppolysomnographysleep restriction

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Area of Science:

  • Neuroscience
  • Endocrinology
  • Sleep Medicine

Background:

  • Voluntary sleep restriction is prevalent in industrialized societies, often driven by a desire for increased productivity.
  • This study investigated the effects of a radically polyphasic sleep schedule on neural, cognitive, and endocrine functions.

Observation:

  • Ten healthy young participants attempted a polyphasic sleep schedule, napping 20 minutes every 4 hours, totaling 2 hours of sleep daily.
  • All but one participant discontinued the schedule within a month; the remaining participant adhered for five weeks.
  • Cognitive and psychiatric measures showed minor changes, while cortisol and melatonin levels remained largely unaffected.

Findings:

  • Growth hormone release was significantly reduced by over 95% and altered in pattern during polyphasic sleep.
  • The radical polyphasic sleep schedule was poorly tolerated, even by highly motivated individuals.
  • Observed decreases in vigilance and neurophysiological sleep changes raise concerns about the schedule's feasibility.

Implications:

  • Radically polyphasic sleep may not adequately fulfill the essential functions of sleep.
  • The findings question the long-term viability and health impacts of extreme sleep scheduling.
  • Further research is needed to understand the neuroendocrine and cognitive consequences of severe sleep restriction.