Circadian Rhythms, Sleep Habits and Water Cooler Dispensers
Definition of Circadian Rhythm
In short, the circadian rhythm is an internal clock that almost every organism on Earth has. For the most part, it controls our wake and sleep schedules to coincide with the rising and setting of the sun. This largely matches the length of a day but is not precisely 24 hours long. Factors that impact the rhythm are exposure to daylight, eating and drinking, heat and others.
Circadian rhythms are dictated by two different criteria. Firstly, they are endogenous which means that they operate independently from outside factors and are able to maintain themselves over time. Secondly that they can be entrained, or adjusted, to fit different circumstances like changing seasons and weather.
Various studies have been done with humans, some of which determine that on average our internal clocks run for about 24 hours and 15 minutes. There are different methods by which our internal clocks maintain themselves. When the eyes receive light they send signals to the brain, calibrating the clock and transmitting that signal through the rest of the body to synchronize organs and bodily functions like hunger and thirst.
Aside from food and water intake, the internal clock is most affected by light, specifically light from the blue end of the spectrum. Even more so, light from above is more impactful to the internal clock than light from below, emulating a bright, sunny sky.
Not to be confused, circadian rhythms do more than dictate when we are awake, but just as importantly when we sleep.
Genetics and the Circadian Rhythm
We all know people who prefer to get up early or like to stay up late. Some of those individuals actually have a genetic deficiency where their internal clocks adhere to a very specific, offset time period. Called advanced sleep phase disorder, this genetic deficiency is inherited where their bodies become exhausted in the early evening and they are wide awake very early in the morning.
For them, their rhythms are hardwired and they are unable to alter their sleep schedule to conform with more normalized or socially acceptable hours. Very rare, this is an inherited disorder that affects a very small number of people.
Common knowledge is that sleep is good. Most of us walk on the "not enough sleep" side of the line, largely to our detriment. We all know that when we get little or poor sleep we all feel lousy. But why? Poor or interrupted sleep causes a whole host of problems like poor job or school performance, susceptibility to illnesses and others. Sleep deprivation adversely affects the brain and organs causing weight gain and loss, poor cognitive function, irritability, etc.
Many records exist of people going several days without sleep using or refraining from using stimulants like caffeine. But, even going 24 hours without sleep causes problems with concentration and mental aptitude and has been compared to being as bad or worse than intoxication.
That isn't to say that sleeping more is better, studies have shown that sleep in excess of 8 hours a day consistently increases mortality rates. The amount of general sleep is less important than the amount of quality sleep.
General tips to improve sleep quality
- When traveling, adjust bedtime by an hour a day in the few days before a trip.
- Stay hydrated throughout the day. An extra trip to the water cooler dispenser at work is a great way to stretch your legs and get a drink.
- Refrain from eating big meals before bedtime. High protein meals are more likely to keep you awake. Where as meals high in carbohydrates can help promote sleep because they increase the availability of melatonin and serotonin, key hormones in the sleep cycle.
- Avoid drinking alcohol as well as caffeine because both increase dehydration.
- Depending on when you are most active, take a nap! Naps benefit those who are active early in the morning, allowing them to "recharge" in the afternoon.