Skipping Sleep is mortally unwise

Every disease that is killing us in developed nations has causal and significant links to a lack of sleep, so that classic maxim that you may [have] heard that you can sleep when you're dead, it's actually mortally unwise advice..." Matthew Walker

Skipping Sleep is mortally unwise
Photo by Jp Valery / Unsplash
"Every disease that is killing us in developed nations has causal and significant links to a lack of sleep, so that classic maxim that you may [have] heard that you can sleep when you're dead, it's actually mortally unwise advice..." Matthew Walker

We seem to be sleepwalking to our deathbeds. New science of the importance of sleep keeps proving its importance in human biology, psychology and human performance, yet, somehow, we keep devaluing its importance.

The sleepwalking hyper-productivity delusion

I'm pretty sure I'm not the only one that has sat trough a conversation with a soundbite going  something like: "oh, yeah, he/she is a genius, and manages with only 4 hours of sleep!", with everybody around "bowing" in amazement of such productive feat (and secretly wishing they could pull it themselves).

It's true, an estimated 1% of the world population can "function" normally with 4h sleep a night... chances are you are not one of them, and probably neither the so called "genius".

The hard reality is there is 99% chance that you need between 7-9h of quality sleep every night, and if you aren't, those extra hours at work (and not sleeping) are not only unproductive, but even leading to costly and time consuming mistakes... not to mention the shortening of your precious time on "here tiny dot floating in space".

Sleep & rest are villains in a world obsessed with productivity. The paradox is that the time "saved" by less sleep & rest does translate to more time at work, but not necessarily to more productivity, on the contrary... The tragedy is that it is shortening our most precious asset: life.

What then happen to our world that we now see sleep & rest like "a waste of time", akin to laziness? And who does the new science of sleep sides with: mum & dad that kept instilling good sleep habits in you, or that boasty sleepwalking psychopath you met at a dinner party?

Quantity & Quality

The US National Sleep Foundation recommends that healthy adults sleep between 7 and 9 hours per night. But be careful trying to get a "beauty sleep" by extending your "horizontal time", new research links longer sleep duration to cardiovascular disease as well. Bottom line: aim at sleeping 8h-ish hours at night, but don't go around "slothing" for too long...

But duration is only part of the equation, quality of sleep is also extremely important.

Now, sleep duration is a concept everyone can understand, and most of us are aware of how much sleep we get (or are we?).

Sleep quality, on the other hand, is a bit vague, and not something the average Joe keeps an eye on. Allow me to pass on some characteristic of good quality sleep across:

  • Sleeping 7-9 hours per night;
  • Falling asleep within 30 minutes, or less, of going to bed;
  • Sleeping throughout the night, or waking up no more than once per night;
  • Falling back asleep within 20 minutes of a nightly loo trip (or that sneaky trip to the fridge);
  • Feeling rested and energised in the morning.

Do you identify with all or any of these?

Importance of sleep in Health, Wellbeing & Performance

In the last decade scientists (like our sleep idol Dr. Walker) have linked poor sleep with many of the ailments of modern life.

Poor sleep seems to be a major contributor to mortality but also a major contributor to poor mental health, low emotional regulation, and even poor performance at work.

Seems like "saving time" by sleeping less is not only "mortally unwise advise", as pointed by Dr. Walker, its also makes us dumb, angry & miserable!

Typical factors behind poor sleep

There are multiple contributing factors to poor sleep, and many can be mitigated or even eliminated.

Sleep duration is an obvious factor. The solution is simple - prioritise sleep. Remember that there is no actual time "saving" coming from sleeping less (unless you are in the lucky 1%... and again, you are probably not!). Obviously there are people which have heavy constraints when it comes to sleep duration & schedule (e.g.: shift work), and others that would gladly sleep longer if they could! But, for the rest of us, we can, and should, sleep longer.

As for sleep quality, here is "where the chickens come to roost". Sleep quality can be impacted by poor sleep habits like irregular sleep schedule, untimely consumption of caffeinated drinks & alcohol, exposure to bright lights in the hours before bed... the list goes on...

Additionally, sleep quality (and to some extent sleep quantity) can be affected by anxiety and stress, certain health conditions (e.g.: sleep apnea), menopause, or by undiagnosed sleep disorder like periodic limb movement disorder (PLMD) - it's complex, but here we can use Julius Cesar's approach: Divide & Conquer.

3 simple tips to improve sleep quantity & quality

Although the heading has the word "simple" in it, I'm fully aware that any of the tips I list below are only simple in concept, and quite difficult to practice... Nevertheless, here they go:

  1. Prioritise sleep: sleep between 7-9h, but no longer than you need to feel rested;
  2. Consistent bed time, even at weekends;
  3. Be serious about sleep hygiene: optimise your bedroom for sleep, invest in  good and comfortable mattress, pillows & bedding (best you can afford), minimise exposure to bright lights, and ingestion of caffein & alcohol 2-3h before sleep, and ensure you mentally unwind before bedtime (you won't sleep if your brain is switched to max). isn't that last tip the "tip" of an iceberg ;)

Better listen to mum & dad!

Mama & Papa kept banging at the importance of sleep every night, so did your teacher when you left a slimy "pool of sleep" at your school desk...  it seems like mum & dad (and your teacher) were right... again!

Once you get over the mental image of your parents telling "I told you so", join Kognitas and start improving your sleep, today!


  1. Sleep Scientist Warns Against Walking Through Life 'In An Underslept State' | link
  2. 'Short sleepers' can get just 4 hours a night and feel fine. But is their health at risk? | link
  3. National Sleep Foundation's sleep time duration recommendations: methodology and results summary | link
  4. Sleep deprivation: Impact on cognitive performance | link
  5. Sleep deprivation and vigilant attention | link
  6. Sleep Duration and All-Cause Mortality: A Systematic Review and Meta-Analysis of Prospective Studies | link
  7. How To Determine Poor Sleep Quality | link
  8. What Is Sleep Quality? | link
  9. Relationship of Sleep Duration With All Cause Mortality and Cardiovascular Events: A Systematic Review and Dose Response Meta Analysis of Prospective Cohort Studies | link
  10. How Much Sleep Do We Really Need? | link
  11. Sleep Statistics | link
  12. Mental Health and Sleep | link
  13. The Amygdala, Sleep Debt, Sleep Deprivation, and the Emotion of Anger: A Possible Connection? | link
  14. Overnight therapy? The role of sleep in emotional brain processing | link
  15. The Link Between Sleep and Job Performance | link
  16. How sleep deprivation affects work and performance? | link
  17. Sleep quality: An evolutionary concept analysis | link