A circadian, solstice-centric sleep schedule, Part I

There is little doubt that modern life disconnects us with the natural cycle of day and night. Light bulbs, monitors, TVs, and even curtains all conspire to give us the power to choose the brightness in our lives. And generally, we do the opposite of what nature intends. Research has noted that the average American gets only about 30 minutes of direct sunlight (over 1000 lux) per day. So paradoxically, we get less sunlight than our Neanderthal ancestors, and yet also less darkness.

Our energy levels and our sleepiness follow a rhythm based on, among other things, the amount of light we see. Therefore, we’re less awake during the day, and less sleepy during the night, and in order to reconnect ourselves to the rhythms of the day, we need to better understand how that connection occurs.

What is the rhythmic connection between the world and our bodies? Externally, there are quite a few: light, temperature, social interaction, and eating and drinking schedules. These synchronizing agents are called Zietgebers (German for “Time Givers”), of which light has the strongest effect our own bodily rhythms. (Obviously, all the Zietgebers listed above are correlated.) Since light is the strongest Zietgeber, the actual connection between the world and our bodies comes most strongly from our eyes. Our retinas pick up the light, which travels through the optic nerve into suprachiasmatic nucleus (SCN) region of our hypothalamus.

What functions to our bodies perform based on these signals? The three most pertinent are body temperature, heart rate, and blood pressure are the most clear.

So, what would be the most natural sleep pattern? Since humans sleep when it’s dark, the most sensible sleep schedule should maximize the percent of sleep done in the dark.

To calculate this, one must figure out what I call the “solar noon” (middle of the day) and “solar midnight” (middle of the night). Interestingly, neither change that much. The changes in sunrise and sunset are close to symmetrical. Just find the time midway between sunset and sunrise.

Next, one should figure out how much sleep one needs. Be generous. For this analysis, I assume that I need 8 hours. For this example, once you have those stats, find the solar midnight, and go to bed 4 hours before then and get up 4 hours after then.

Part II will get more specific.