I have been doing some research into sleep chronotypes and how they affect our quality and quantity of sleep. I’d like to take a look at the types of chronotypes, how they change as we grow older and why we can create better lives if we adjust our schedules to them.
There are three kinds of people when it comes to sleep: larks, “third birds” and night owls. Your chronotype is whenever you naturally feel like sleeping beyond the influence of alarms, commitments, outside pressure and lack of sleep. When you would sleep on a deserted island with no cell service and no anxiety. That’s your chronotype. The larks have a sleep midpoint of about 1-2AM by nature, without alarms. The “third birds” sleep a little later, with a midpoint of around 4AM. The night owls have a sleep midpoint of 6-9AM.
When we’re young, most of us are larks. As we get to elementary age, most of us become “third birds”. In our teenage years, most of us become night owls. At the end of our teen years, our chronotypes stabilize for a few decades until we get older. This is why teenagers are known for staying up “way too late”, and sleeping in “way too late”. Their bodies are producing chemicals that put them to sleep until later in the morning and don’t start making them feel sleepy until later at night.
If we sleep at our natural chronotypes, we are able to fall asleep faster and get a greater quality of sleep. This can have a serious impact on our lives. If we’re always sleepy during the day, have a hard time focusing or getting anything done, it’s probably either due to overall sleep deprivation or not sleeping at our natural chronotypes. In our natural sleep cycle, we have slow-wave sleep (deep sleep) where our bodies are repairing themselves, growing (depending on our age) and moving the memories of our day from short-term to long-term memory. We alternate between slow-wave and REM sleep which is where we dream, and our brain is throwing out a bunch of random ideas together to see what connects and what really matters (and thus what should be remembered). REM sleep is also where our brain repairs itself so we can think well and focus the next day. If we don’t sleep according to our chronotypes, we stand a high risk of loosing REM sleep. For example: If your natural chronotype was 12AM to 8AM but you had a meeting in the morning, so you needed to wake up at 6AM. You sleep 6 hours instead of 8, and lose 25% of your sleep. But, you could be loosing as much as 80% of your REM sleep because REM sleep comes much more frequently later in our sleep cycle.
Experiment. Find your chronotype, then stick to it as much as you can. We can’t be perfect, and we can’t control everything, but let’s cut the “social jetlag” to a minimum. I hope you can see how sticking to your chronotype is a recipe for longer, better sleep that will improve your quality of life. For more on how getting more sleep helps you perform better and live well, see my blog post on sleep.