Getting in Rhythm: How Your Internal Clock Effects Your Sleep and Weight

By June 29, 2016 Articles No Comments


Have you ever gone on a vacation or business trip where you found yourself struggling to adjust to the time-change?

What about coming home from college and having to adjust to an early morning job after months of pulling all-nighters?

Or, how about one night of struggling to go to sleep a few hours early because you needed to get up much earlier than normal the next day?

At some point or another we have all experienced poor sleep due to an abrupt change in schedule. The culprit behind this decline in your sleep quality is a term you may very well be familiar with, circadian rhythm.

Circadian rhythms, however, are responsible for more than making it difficult for you to adjust to a new schedule or time zone. They affect numerous processes that occur within our bodies; influencing how our bodies feel and function throughout the day.

In other words, circadian rhythms play a tremendous role in your daily performance and productivity, ultimately helping or hindering you from reaching your health and fitness goals.

So, today we are going to discuss what exactly circadian rhythms are, how they affect you, and how they can be managed to help you reach your goals.


What are Circadian Rhythms?


Our circadian rhythm is essentially a 24-hour biological clock that operates within our brain in what is called our suprachiasmatic nucleus.

Supercalifragilistic what…?

While that long, near-unpronounceable word isn’t important to remember, what is important is that many of the physiological and biological patterns that take place within our body run off this “inner clock.” It influences when we’re hungry, when we need to go to the bathroom, and when we’re most coordinated.

Circadian rhythms have a significant effect on numerous body functions. This includes neuroendocrine function, influencing the release of many hormones within our bodies. Because of this, if our circadian rhythms become misaligned, it may lead to, among other conditions, metabolic disturbance, decreased brain function, and increased risk for obesity and cardiovascular disease.


What Controls Circadian Rhythms?


Our circadian rhythms are heavily dependent on our environment, specifically our light environment.

Exposure to natural sunlight essentially has an anchoring effect on our circadian rhythms. Our bodies adapt to the normal hours of light and darkness, and adjusts many body functions accordingly.

However, natural sunlight is not the only light we are exposed to that affects our circadian rhythms. The same bright and vibrant “blue light” that is emitted from the sun, specifically during the middle of the day, is now exposed to our eyes and brains at all times of day through our phones, tablets, computers, and televisions.

Now, ideally what we want is a good amount of blue light exposure during the day, with minimal or no exposure at night.   However, many of us now have jobs where we work indoors all day with little or no exposure to natural sunlight. Then, many of us go home and watch TV or work on our computers, exposing ourselves to artificial blue light which stimulates the brain, masking sleepiness.

So, not only are many of us missing out on circadian anchoring blue light during the days, but we are also compounding the problem by creating artificial daytimes within our homes at night. Since the light our eyes are exposed to effectively signal the brain to switch on or switch off, many of us, for all intents and purposes, are causing our own sleep deprivation through excessive use of blue light-emitting devices at nighttime.

This is why, in large part, the average sleep time for adults in America has decreased 20% over the last 50 years.


Sleep/Wake Drive


Now that you know how light influences our circadian rhythms, lets break things down a little deeper and discuss two functions that affect our sleeping patterns; our sleep and wake drives.

What the heck are the Sleep and Wake Drives?

Once again, light is responsible for controlling what we can refer to as our wake drive. As our eyes take in light throughout the day, it continually alerts the brain fueling this wake drive.

On the end of the spectrum is our sleep drive. This gradually builds throughout the day after we wake. However, the sleep drive is not really a linear build throughout the day where you gradually get sleepier and sleepier.

How do these work?

What happens is that the sleep drive and wake drive work off each other to help our bodies function properly throughout the day.

As our sleep drive builds throughout the day, it counteracts our wake drive, fueled by our exposure to light. As light exposure decreases in the evening, wake drive decreases and sleep drive gradually takes over.   It is this build of sleep drive, working unopposed that allows us to stay asleep for multiple hours.

However, when you are unable to completely eliminate this sleep drive, you carry extra into the next day. Overtime, this leads to what is known as partial sleep deprivation. Many of us live with partial sleep deprivation, consistently failing to get an adequate quantity and/or quality of sleep.


Managing Circadian Rhythms for Sleep of Epic Proportions


So, the question now is, how do you manage these systems to improve your sleep?

Well, here are three steps that should have you well on your way:


  1. Manage Your Light Exposure


The main point here is, stop giving your brain the wrong signal at the wrong time.

Aim for a minimum of 1 hour of outdoor light exposure everyday, preferably as close to noon as possible. Try exercising outside, going for walks outside on your breaks, or eating your lunch outside or at least next to a window. This anchor light will help prevent light exposure later in the day from throwing off your rhythm.

In addition, try to mimic the tone of natural light over the course of the day. This means, limiting exposure to blue-light emitting devices after dark.

If you have to work, or need to use your computer, download the application, F.lux. This app adjusts the backlight on your computer to mimic the tone of outdoor light throughout the day, emitting bright blue light during the day, and a warm, incandescent orange light in the evening and after dark.


  1. Set a Caffeine Cutoff

Of all the different substances that are commonly over-consumed, it seems as though caffeine is the one that most often gets a free pass.

Now, I’m not going to go into a rant about how you should cut out all caffeine intake. I know I’m not giving up my coffee anytime soon. I mean, that might put my local Starbucks out of business.

That said, I think most of us have experienced first-hand how caffeine can delay that sleep drive from overpowering the wake drive. Or, in other words, we know it will keep us up later. However, not only does caffeine delay sleep initiation, but it also adversely affects sleep quality.

Generally, it is during the first stage of sleep where sleep drive is reduced. Caffeine, however, lightens sleep during this stage, preventing reduction of sleep drive. As a result you will wake up the next morning less rested, to the point where, for example, 8 hours of sleep may now feel like 5 or 6.

So how do you prevent this?

Well, again, I’m not going to tell you to give up caffeine completely. That would make me a hypocrite. However, it is a good rule of thumb to cutoff all caffeine consumption after 3pm.

While some people may metabolize caffeine fairly quickly and others may be quite sensitive, this 3pm cutoff should prevent any adverse effects on sleep quality.


  1. Consistency, Consistency, Consistency


The final piece of this puzzle is, well… consistency.

Our bodies crave a regular schedule. It is better prepared for deep, restful sleep at specific times. Because of this, 8 hours of sleep during a normal time period is more restful than 8 hours outside that time period.

For example, if you can routinely go to bed at 10pm Sunday through Thursday, waking up at 6 am, your body will find this sleep more restful than when you go out on Friday night, and then sleep from 2am to 10am.

Having regular sleep and wake times solidifies your circadian rhythms, allowing you to get to sleep quicker, get higher quality of sleep, buffer your sleep drive, and wake up feeling refreshed, recovered, and ready for the day ahead.


Buck the Trend


We are a sleep deprived society.

However, instead of tackling the issue as a whole, we have adapted. We have grown accustomed to the feeling of inadequate sleep, getting by loading up on coffee, energy drinks, and other stimulants.

The truth is we have forgotten what it’s like to be truly rested on a regular basis.

It’s time to reverse this trend, taking the necessary steps to solidify our circadian rhythms to increase sleep quality and rejuvenate our bodies.

Yes, it will take some work and require some new habits. But by taking these steps, I guarantee you will find yourself more productive, more energized, and accelerating toward your health and fitness goals.

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