The self-perceived ideal amount of sleep may not be the true biological sleep need, and many people may be operating below their potential due to an unrecognized sleep debt.
There may not be a clear upper limit to optimal sleep duration, as sleeping up to 8.75 hours a night showed improved cognitive abilities and positive changes in hormonal health and stress markers.
Deep dives
Optimal Sleep Duration: Uncovering the True Sleep Need
Two independent studies conducted in Japan and the US/UK reveal that the self-perceived ideal amount of sleep for individuals may not be their true biological sleep need. The studies involved participants staying in controlled laboratory environments to determine their optimal sleep duration. In both studies, participants initially slept for longer periods, indicating a rebound from accumulated sleep debt. However, as the studies progressed, participants settled into a steady state equilibrium of approximately 8.75 hours of sleep a night on average. These findings suggest that many people may be operating below their potential due to an unrecognized sleep debt. Furthermore, the increased sleep duration demonstrated improved cognitive performance and beneficial effects on blood sugar levels and hormonal health, debunking the notion that more sleep is harmful.
Age and Individual Variations in Optimal Sleep Duration
It's important to note that both studies focused on young, healthy individuals. The optimal sleep duration of approximately 8.75 hours a night may not apply universally. Further research is needed to determine the specific sleep needs of different age groups. However, an additional study involving older adults showed that they tended to sleep for about 7.4 hours a night when given the opportunity. Therefore, it remains unclear how sleep needs may change across different stages of life, and it is unreasonable to apply the findings of these studies to individuals in their thirties, forties, or beyond.
Challenging the Idea of Too Much Sleep
While it is not yet definitive, the studies suggest that there may not be a clear upper limit to optimal sleep duration. Contrary to the belief that too much sleep is harmful, the studies found no negative consequences of sleeping up to 8.75 hours a night. In fact, participants exhibited improved cognitive abilities and positive changes in hormonal health and stress markers. Nevertheless, it is important to consider that like food, water, and oxygen, sleep may follow a balance between sufficiency and excess. Further research is needed to explore the potential risks of excessive sleep duration.
This week, Matt introduces a new segment called "Hot Off the Press," where he covers the latest and most exciting studies in sleep science. And the topic of discussion for this first installment is a great one: excessive slumber - exploring the questions of whether one is getting enough sleep and if there is such a thing as too much sleep. Listen in today to find out if too much sleep can be harmful in the same way that too little sleep is, whether or not there may be an upper limit to the benefits of sleep, or if further research is necessary to provide a conclusive answer to either of these crucial questions.
Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.
The good people at InsideTracker are one of the sponsors of this week's episode, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link during the time window of this episode. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.
Another sponsor this week is the biochemical electrolyte drink company LMNT, and they are very kindly offering eight free sample packs when you purchase any one of their orders at drinklmnt.com/mattwalker. LMNT is an electrolyte sports drink that I can get behind - it's created from the basis of science, and it has no sugar, no coloring, and no artificial ingredients – all qualities that are so important to maintaining your blood biochemical balance. If you want to give LMNT a try, just head on over to drinklmnt.com/mattwalker and get your eight free samples with your first purchase.
As always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.
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