This short chapter will teach you how to set up your sleep cycle upon waking in the morning. Starting your day like this will help you to get to sleep better and stay asleep for longer.
This information applies to all people (except those who are completely blind). Additionally, the education in this chapter comes from two sources:
· A book entitled “Why We Sleep: Unlocking the Power of Sleep and Dreams” by Dr. Matthew Walker (Walker, 2017)
· Huberman Podcast: Dr. Andrew Huberman (Huberman, 2021)
Why We Sleep
Sleep enriches a diversity of functions within the brain, including our ability to learn, memorize, and make logical decisions and choices. Sleep recalibrates our emotional brain circuits, allowing us to navigate next-day social and psychological challenges with cool-headed composure (Walker, 2017)
In the body, sleep builds up our immune system, helping to prevent infection and ward off sickness. Sleep reforms the body’s metabolic state by fine-tuning the balance of insulin and circulating glucose. (Walker, 2017)
Sleep also helps to regulate our appetite, helping to control body weight through healthy food selection rather than rash impulsivity. Sufficient sleep maintains a flourishing microbiome within your gut from which we know so much of our nutritional health begins. Adequate sleep is intimately tied to the fitness of our cardiovascular system, lowering blood pressure while helping keep our hearts in fine condition. (Walker, 2017)
Needless to say, we need our sleep as it will help with overall physical, mental, and emotional well-being and help us to live a longer and healthier life.
The information in this section applies to those who are waking up during daylight hours or just before sunrise and going to bed when it is dark outside or just prior to total darkness. If you are doing shiftwork, please refer to www.thepdbook.org for protocol.
Setting up your sleep-wake cycle
Step 1: Upon Waking
· first thing in the morning, expose your eyes to natural light for a couple of minutes or more
o ideally, this means that you go outside and look up! Look towards the sky (but don’t look directly into the sun)
o looking through a window is better than not taking in natural light, but being outside will help to set up your sleep-wake cycle better than looking through a window
o it doesn’t matter if it is cloudy or sunny. You want to take in natural daylight from above
The cells in the lower part of the retina are constantly viewing what is above us. When these cells sense light after sleeping, the activation of the sleep-wake cycle should begin.
How and why does this occur?
The eyes are a part of the brain, and the retina has cells that are designed to detect sunlight. These cells primarily reside in the lower half of the retina. (Huberman, 2021)
Because of the location of these cells in the retina, they are continually sensing light (or lack of light) from above. They are viewing our upper visual field. (Huberman, 2021)
Once these cells detect light from above, they trigger the brain into kicking in the wake cycle. This creates the production of cortisol and starts an internal clock within your body and brain setting you up to stay awake for approximately 14-17 hours (this number varies from person to person). (Huberman, 2021)
As you go through your day, your sleep-wake cycle clock is ticking.
Eventually, it will be time to go to sleep at night.
Step 2: Setting up the sleep cycle
· an hour or so prior to sundown, step outside and look up at the sky for a couple of minutes (avoid looking at direct sunlight)
o again, it is best to be outside and look up rather than looking through a window
o it doesn’t matter if it is cloudy or sunny. You want to take in natural daylight from above
Viewing natural light from above before sundown triggers the brain to produce melatonin, a hormone that helps us get to sleep.
This simple sleep-wake cycle process can be a game changer for those who have difficulty sleeping.
Other important considerations
After going to sleep at night, it is important to avoid bright light.
For example, perhaps you need to use the bathroom. If you feel safe walking in the dark (and have the ability to navigate to the bathroom without tripping or falling), walk in the dark or place a very dim light lower on your horizon (i.e., nightlight in an outlet near the floor).
Especially between the hours of approximately 11:00pm and 4:00am, it is important to avoid bright light, if possible. (Huberman, 2021)
Exposure to bright light from above during these hours are likely to trigger your wake cycle, causing difficulty getting back to sleep. (Huberman, 2021)
Turning on an overhead hallway, bedroom, or bathroom light may trigger the wake cycle prematurely.
Looking at your phone, tablet, or computer may prematurely trigger the wake cycle.
Do your best to practice the process outlined above. This may be the answer to better sleep for you!