Episode 94: Our forgotten relationship with Sleep

How much do you sleep? What time of the day are you most awake?  These are questions of our circadian rhythms, our natural biological clocks…you know the ones we try to side-step with caffeine, electric lights and our super-human work ethic?

Sleep is apparently one of our must underrated health habits.  In her book ThriveArianna Huffington argues that “sleep, or how little of it we need, has become a symbol of our prowess.”

This week, Clay and Sarah discuss sleep, day-time cycles of alertness and how we experience our natural bio-clocks.


In this episode:

  • Morning person, Night owl – which are you?
  • Evolution and our natural sleep cycle
  • Why sleep is important
  • Sleep deprivation as torture
  • The Man Who Stares at Goats (and other strange military experiments with sleep)
  • Chronopsychology, what psychologists know about our daily biorhythms
  • How we can re-orient our schedules in tune with our personal bio-clock


Life evolved under conditions of lightness and darkness, Jessa Gamble reminds us in her TED talk on our natural sleep cycle.  And every multi-celled organism including all plants and animals have development an internal clock to be ready for these changes.

Gamble was part of a research team that studied people’s bio-clocks when they were taken into an underground bunker where there was no outer queues of natural light to tell people whether it was day or night.  What these researchers found is that our bio-clocks are fairly stable, and so even when people are living in conditions of no natural light or clocks to tell them the time, they still wake up at approximately their usual time and go to sleep at night.

What was interesting was people’s sleeping patterns under these conditions.  Researchers found that people tended to sleep twice a night… once from about 8pm to midnight and again from 2am to sunrise.  In between midnight and 2am they experienced a period of meditative quiet.  These people reported feeling incredibly awake during the daytime.

Chronopsychology is a new field that studies human bio-rhythms.  This field has found that on average, people are at their intellectual best between 10am-1pm, that we usually have a midday slump where brain speed slows, and that brain performance (i.e. attention, memory, thinking, reaction time) picks back up between 4-8pm.

We both found it interesting this week to reflect on our own natural tendencies… to acknowledge how much sleep we need, when we feel most alert and productive and how we might orient our day around these natural cycles, rather than simply drinking more caffeine (though as you know, our loyalty to coffee holds strong!)

Hope you enjoy this week’s episode on a topic we rarely consider despite how much it impacts us on a daily basis!