Article excerpt. Georgia Frances King.
Every organism on the planet sleeps in some fashion, to some degree – even the basic fruit fly. What makes sleep so essential for our wellbeing comes down to three main things:
- to save our energy
- to help our cells recover
- to help us process and understand our environment
During the day, we make all these connections with the world around us. The excitatory connections we make during the day result in the neurons in our brains getting overall higher activation. Then during the nighttime when we sleep, we have a down-regulating process where the things that didn’t really matter to your survival sink to the bottom, and the things that are most relevant to your survival rise to the top.
Sleep stages: light sleep > deep sleep > light sleep > REM, and repeat.
As you sleep more, you get less and less deep sleep, and also if you sleep-deprive yourself, you get more deep sleep. Deep sleep is really important, but REM sleep is also important.
We know that the human growth hormone, cell-recovery things, and the ability to process new information are associated with deep sleep. REM sleep is basically the processing of information.
Every organism is responsive to a circadian rhythm that’s largely dictated by sunlight. The photo receptors in our eyes pick up on sunlight, which controls the release of melatonin and all these other neurotransmitters that dictate your energy levels throughout the day.
You have a peak moment of awakeness during the morning. After lunch you usually have a glucose spike, especially if you have a big heavy lunch. That glucose spike combined with a circadian dip gives you a period of fatigue between around 2 and 4pm. You’ll then have another spike in alertness right before dinner, and then you’ll start getting tired again closer to bedtime. That’s your 24-hour circadian rhythm, basically.
Then there’s also something called “chronobiology.” You actually have genes that dictate whether you’re a morning person or an evening person. And then some people have genes that make them very flexible. The environmental cues they react against are called zeitgebers.
Your biggest zeitgeber is sunlight, and that’s the environmental cue that controls energy levels as well. But then also timing of meals, exercise, and having a consistent bedtime are all zeitgebers that impact your circadian rhythm. A bigger part of the problem is that we’re indoors so much now, so we don’t get that natural occurring sunlight when you wake up in the morning. That’s one of the best things that you can do to entrench your circadian rhythm.
If your circadian rhythm is off, it negatively impacts your sleep quality. So having that consistent rhythm of going to bed and getting up at the same time will actually make your sleep more regenerative at night. Going for a walk outside and getting that sunlight in the morning is the best thing to do to wake up. Your circadian rhythm isn’t a fixed thing: It’s actually shiftable based on your environmental cues.
Gallup has reported that over the past 50 years, we’re sleeping a whole hour less per night than we did in the 1950s. That’s a lot. A lot of that has to do with having TV on all the time, and mobile phones are taking it to the next level.
You want a cold, quiet environment with no light: That’s basically the ideal way to improve your sleep quality. However, people have a different ideal sound, light, and temperature environment to improve their sleep quality.
SOUND: Quiet environments are going to improve your sleep quality. Your brain has these micro arousals throughout the night without you being consciously aware of it—even an air-conditioning unit turning on wakes up your brain. So blocking out noises is a low-hanging fruit to improve your sleep quality.
TEMPERATURE: Everyone has different natural body temperatures.
LIGHT: The other thing is no blue light close to bedtime. There are a lot of studies that screen time close to bed is bad.
STRESS: When you’re stressed, your flight-or-fight response is active during the night, and your sleep quality is going to be shallow.