Melatonin and Sunlight
Have you ever wondered why human beings sleep at night? Did someone just make the decision one day: “Okay Guys! From now on we’re all going to go to sleep when the big light in the sky turns off!”
That could possibly be it! But there’s actually a system inside of us that uses light and darkness to control certain sleep hormone levels.
Melatonin is a hormone synthesized in the pineal gland and, to a lesser extent, in the retina. Melatonin is responsible for putting you to sleep and restoring physical energy while we sleep. If your melatonin levels are high, you will experience feelings of drowsiness, loss of energy, etc.
Melatonin is released when we’re exposed to darkness. The instant sunlight stops entering our eyes, our melatonin hormone level begins to rise. Your melatonin levels are EXTREMELY dependant on the amount of natural sunlight that enters your eyes during the day!
Higher exposure to sunlight
delays the body temperature drop, and lets you stay awake and alert longer. Poor exposure to sunlight will promote a quick temperature drop and make you feel sleepy, tired, and out of balance. You will most likely experience the pressure to sleep very early in the day, or the pressure to sleep will be very minimal which might cause insomnia and poor quality sleep.
Because melatonin is released when we’re exposed to darkness, it is also sometimes called the vampire hormone.
We’ll explore exactly how important sunlight is in a later part of this book. However it’s important to understand that getting proper sunlight isn’t an “optional” part of this program, it’s a MUST, as it is the main way our body adjusts our body temperature rhythm.
The amount of movement and cardiovascular exercise you get during the night has a huge impact on your body temperature rhythm. Any movement or exercise promotes a quick rise in temperature which can be very beneficial to the sleep system.
Exercise creates a higher “peak” point of body temperature during the day, which will increase your energy levels far beyond anything else. Exercise delays the body temperature drop at the end of the day, allowing you to stay awake and alert longer.
Finally, exercise will make the drop of body temperature at the end of the day more drastic and allow your body temperature to stay lower for a longer amount of time; this will promote much deeper sleep.
Obviously the amount of time you’re awake has a direct effect on all three factors above. Your activity levels contribute a lot to your temperature variations. Also, the longer you’re awake obviously means you get more potential for sunlight entry into your eyes, which has a direct effect on your melatonin level.
If you’re currently sleeping 8 or 9 hours and you feel tired during the day this could actually be a sign that you need LESS sleep. You’re sleeping too much and you need to increase your prior wakefulness to create deeper sleep and a more balanced body temperature rhythm.
The four factors up above control how long you sleep, and how deep your sleep is. To summarize, the factors that affect your sleep the most.
1) The body temperature rhythm.
2) Natural sunlight entering your eyes, as it has a direct effect on your melatonin levels.
Understanding how the body temperature rhythm affects your sleep is the key to optimizing your sleep. The body temperature rhythm is really what makes the sleep clock a… “Clock”.