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How are Sleep & Circadian Rhythm Connected? | StupidEasyPaleo.com

How are Sleep and Circadian Rhythm Connected? [Oct 2018]

To understand how to get better sleep, you first have to zoom out and take a look at circadian rhythm.

How are Sleep & Circadian Rhythm Connected? | StupidEasyPaleo.com

Sleep’s Connection to Circadian Rhythm

In this audio training, you’ll learn how sleep is connected to circadian rhythm. You’ll also learn how to readjust your circadian rhythm via light exposure.

Pillar: Recharge Your Energy

Click the play button below (or read the transcript if you prefer). Please note that this is not a publicly available podcast, so you won’t find this listed under Harder to Kill Radio in your podcast app.


00:01 The reason why I put sleep before nutrition, a lot of people think, “Okay, first I have to get my nutrition dialed in, and then I’m going to add an exercise. Then, later on, I’ll think about sleep.” But, sleep has far-reaching implications on a host of different things, your body composition, your cravings, your mental clarity, your performance in the gym, at your job, your relationships and mood. It is so, so, so clutched. So, we’re going to take a look at why sleep matters and get into the what and the why and the kind of rationale behind all this stuff so that you can really get a better sense.

00:47 So, why does sleep matter to your body? In the simplest sense, sleep is restorative to your body and your mind. If I had to sum it up in one sentence, it would be that. But as we know, the body is very complex. There’s lots of stuff going on that we never even have to think about. It just happens automatically. So, sleep is so much more detailed and nuanced. There’s lots of stuff going on under the hood or below the surface. So, let’s take a step back almost and look at what controls sleep and how it’s orchestrated by the body.

01:36 Sleep is controlled by a delicate dance between internal and external processes and cues. What that means is some parts of sleep are governed by things that, again, are completely automatic to you. Other parts of sleep you have to build into your routine. You have to train your body. You have to set yourself up for success. Some things like hormones and our hormonal balance can be controlled by things like what we eat or the stimulus that we expose ourselves to. So, just kind of know that it’s not as simple as saying, “I’m just going to put my head on the pillow a little bit earlier at night.” It might be more involved for you than that.

02:22 If you have problems sleeping, and we’ve all been there, it can feel like a downward spiral because all of these processes, and these cues, and the hormones, and the external and internal things that are going on in our lives all feed back into each other, and so it can make the problem seem worse, and worse, and worse. Then, you start to really get stressed out about it. The good news is it is possible to get a great night’s sleep, even if your sleep isn’t very good right now. The bad news, this isn’t always what people want to hear, but it’s often a multifaceted approach that takes discipline, and good habits, and reinforcing those habits on a regular basis.

03:11 The really interesting thing, and I sort of love this analogy, is that when if you have children, or you’ve ever taken care of small children, or you remember being a child, oftentimes, we create these bedtime routines for little kids to tell them like, “Hey, it’s time to wind down and go to sleep.” If you ever had situation where there was no bedtime routine as normal and kids are bouncing off the walls, it’s hard for them to wind down. But then, for some reason, we think as adults we don’t need that stuff, and it’s actually one of the downfalls. It’s relatively simple to fix, maybe not easy, but the fixes are often very simple. Now, I mentioned this term circadian rhythm. I think this is really critical to understand, is that sleep is one facet of the larger circadian rhythm that runs approximately 24 hours. Now, circadian, circadian means around the day. So, this is kind of like, what is the 24-sh hour cycle that governs our day?

04:26 Now, one of the other major facets of circadian rhythms is feeding cycles, is when we eat. This is very interesting because the two are very closely connected. We’re not going to focus on the eating part quite yet, but I want you to think of the circadian rhythm as your internal clock. And by the way, it’s way smarter than you. It’s very hard to outsmart your circadian rhythm. This rhythm, this internal clock controls our feelings of sleepiness and wakefulness. It controls our metabolism, our hormones, and so much more.

05:02 Now, if you have teenagers or you remember being a teen, you probably remember that your sleep felt so weird, and that’s because sometimes circadian rhythms can shift based on our process of human development. So in adolescents, especially that time of tremendous hormonal change and growth, circadian rhythms can shift a little bit. You might notice that teenagers, they often go to bed a lot later and then they get up a lot later, and we’re like, “Hey, you need to get up and go to school at seven,” and it’s a battle to get them out of bed. A lot of that is just actually their circadian rhythm. It’s not something they’re doing on purpose.

05:42 You may also notice that you wax and wane throughout the day. You may feel more alert or less alert. There’s a very common window between about one and three in which a lot of people actually just feel less alert. I personally find it’s really hard to get work done during this period, even though my energy level feels pretty stable. You may notice that if you eat really sort of carb-rich, quick-to-digest carbs at lunchtime, this only makes your feelings of sleepiness worse. So, that’s one of the reasons why getting good sleep is key to sort of smoothing out these bumps.

06:24 Now, what’s really interesting is your circadian rhythm sustains itself. You don’t have to do anything. It’s like when you breathe normally. If you’re focusing on your breathing, that’s a different story. But, these things happen without you having to focus on them. And they are adjusted to your environment based on cues like light and temperature. Your body can adjust to changes in circadian rhythm. Think of anytime you’ve ever had jet lag. Ugh, the worst. Jet lag is so hard, right? You shift your body into a completely new time zone, and it takes time and exposure to other cues to get back on track. Eventually you will, but it’s very hard to completely flip or shift dramatically your circadian rhythm.

07:16 All right. So, how to sleep fit into all of this and sort of what’s the connection? The sleep connection to circadian rhythm … And I’m going to try to keep it super brief, but if you’re into the nerdy stuff, there’s a little bit more to the story. There is part of your brain called the hypothalamus. The hypothalamus is one of the most ancient, sort of deep structures of the brain. It’s one of the oldest structures of the brain. In the hypothalamus is a cluster of neurons called the SCN, the suprachiasmatic nucleus. You don’t need to remember that name. Just know that there’s a part of your deep, ancient brain that controls your circadian rhythm. Now, very, very interesting when this is related to sleep because the input that your eyes receive, the light that travels into your eyes, travels through signals down the optic nerve. You can almost think of it like a light highway to your brain. The optic nerve is like a light highway or a freeway, depending on what part of the country you live in. That direct path from the optic nerve goes right to the SCN and gives information to the pineal gland. Now, the pineal gland sits just below the hypothalamus. Why is the pineal gland important? Because it releases melatonin, and melatonin is the hormone that controls sleep. Very, very, very key. You’ve got light coming in through your eyes. It’s going to eventually be transmitted via impulse to that part of your brain, the SCN. Then, that region of the hypothalamus is going to then cause that pineal gland to release melatonin.

09:09 Now this is very interesting. Think of it like two sides of a coin. When light gets into your eyes, it signals your brain and your body that you’re awake. It’s awake time. Light means awake. We’re so tied to the sun, right? So when you’re getting light in your eyes, it says, “Okay, be awake.” When it’s darker and you’re not getting that light stimulus in through your eyes … And by the way, this also happens across the skin, which is super kind of creepy, but it’s … Your skin is able to sense light as well. When you’ve got less light coming into your eyes, that’s a signal to release melatonin, which is the signal to sleep, okay? So, keep those two sides of the coin in mind.

09:59 Here’s a very simplistic summary. You need the correct timing of light and dark to support an optimal circadian rhythm, sleep, and overall health. Now, think about what we have done as human beings. We have attempted to screw with our circadian rhythms like crazy. We have night shift jobs. We have artificial light. We have social media and screens that we’re holding up to our eyes when we should be sleeping. All of this causes our circadian rhythms to be a little bit out of whack and our sleep. When we really try to screw up our circadian rhythms, and if you think about people who are suffering from severe disorders in which their circadian rhythms are affected, a lot of times what we see is an increase of chronic disease in these folks. So, screwing up our sleep, and playing with our circadian rhythms, and trying to really shift them over a period of time can have serious results, up to and including chronic illness and chronic disease, obesity, you know, you name it, mood disorders. So, there’s a lot at stake here. A lot at stake.

11:19 So, I don’t want you to feel depressed if you’re having trouble sleeping. There are some things you can do to try to get back to your normal rhythm. And trust and know that your body has the right. It’s got the right stuff. You just have to feed it the right signals. And when you can get the two in alignment, you’re going to sleep very soundly.

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Steph Gaudreau

Hi, I'm Steph Gaudreau (CISSN, NASM-CPT)!

Nutrition and fitness coach for women, Lord of the Rings nerd, and depending on who you ask, crazy cat lady. My mission is to help you fuel for more: bigger muscles, strength, energy, and possibilities. We’ll do it with my signature blend of science, strategy…and a little bit of sass.


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