Productivity hacks are abundant on blogs, podcasts, and social media. These tips are promoted as efficiency boosters in a relentless quest for optimization. If you’ve ever explored potential sleep hacks, you’ve probably come across proponents of polyphasic sleep

Sleep experts have long expressed concern about the negative consequences of polyphasic sleep. A new study published this month has added fuel to the fire by finding a steep drop in growth hormone production after just a few weeks on a polyphasic sleep schedule.  

Polyphasic sleep breaks the sleep schedule into three or more separate segments during a 24-hour period. It stands in contrast to monophasic and biphasic sleep, which involve one and two sleep sessions. According to polyphasic sleep advocates, it enables you to sleep for only a few hours each day, providing more time to get things done. Famous thinkers and inventors, such as Leonardo Da Vinci and Nicolas Tesla, are reported to have followed polyphasic sleep schedules to gain more productive hours per day.

In the new study, 10 people between the ages of 21 and 28 agreed to sleep according to the Uberman polyphasic sleep protocol. Under this schedule, you sleep in 20-minute increments every four hours throughout the day and night. These six sleep sessions add up to two hours of sleep every day. 

Although participants agreed to follow the Uberman schedule for 8 weeks, not a single person could tolerate it for the full allotted time. Nine of the 10 participants quit the study within three weeks. One person lasted five weeks but broke with the schedule by accidentally sleeping through an alarm on 13 of the 35 days. On two occasions, he ended up sleeping for 10 hours. 

These difficulties demonstrate that polyphasic sleep is frequently impractical and unsustainable. But the observed impact on growth hormone may be even more concerning. 

Before dropping out at five weeks, one participant completed a battery of tests that revealed a 95% drop in his growth hormone level. With a typical sleep-wake schedule, there’s a surge of growth hormone during evening sleep. This study suggests that polyphasic sleep can significantly disrupt this normal pattern of hormone production. 

The dramatic decrease is worrisome because of growth hormone’s role in metabolism, bone and muscle development, mood, memory, and thinking. Although testing in the study did not find noticeable physical or cognitive problems, past research has shown numerous potential harms from polyphasic sleep. 

Virtually no polyphasic sleep schedule provides enough time to get the minimum 7 hours of sleep that experts recommend for adults. As a result, polyphasic schedules can contribute to problems associated with sleep deprivation, including impaired thinking, car accidents, reduced productivity, and metabolic and heart diseases.

This isn’t to say that every minute of daily sleep must occur in a single session. Many people supplement nightly sleep with a nap as part of a biphasic sleep schedule. Some evidence even suggests that a biphasic schedule was common before electricity became widespread. 

However, polyphasic sleep represents a more dramatic departure from typical sleep schedules, and the newest research only reinforces the need for caution when trying to hack sleep by ignoring sleep hygiene.

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4 Sources

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  3. Faletto, J., (2019, August 1) Leonardo da Vinci and Nikola Tesla Allegedly Followed the Uberman Sleep Cycle. Discovery Science., Retrieved February 20, 2024, from
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