Does this sound like you:
- You can’t fall asleep at all, even if you’re tired. Your mind is racing.. you can’t turn it off. You’re likely stressed out.
- You fall asleep but can’t stay asleep. You’re a very light sleeper
- You sleep through the night but wake up tired – no matter how much sleep you get.
If any of those points resinate with you, you must read this whole article! Sleep is absolutely essential to a healthy body and mind. Let’s take a closer look at important things you might not know about sleep.
Why do we need sleep
I think everyone who’s ever struggled with sleep can attest to the fact that lack of sleep can seriously affect your mood, cognitive capability, and leave you feeling generally stressed overall. When you’re not well-rested, you just don’t function very well. But sleep is about so much more than just resting. Many of your body’s systems rely heavily on sleep in order to do their jobs. And without enough sleep, health can suffer far beyond just feeling rundown during the day. Although I’m sure you’re already committed to getting better sleep, I think it’s important to know exactly what’s at stake, and just how much you will benefit once you brake up with your sleep problems.
Physical Repair and Energy
The body uses sleep to repair itself physically, and this has been shown to happen during the first half of the night, between 10pm and 2am. Without enough deep sleep during these hours, your body can’t rejuvenate cells in your muscles and other tissues, which can lead to physical weakness and illness. Deep sleep renews physical energy—most of the body’s blood volume is sent to the muscles during sleep, allowing them to replenish with nutrients and oxygen so they can regenerate energy.
Deep sleep provides an ideal biological environment for the immune system to do its job—which is why you’re finding yourself even more prone to getting sick when you’re not sleeping well, and why your body wants to sleep so much more once you actually are sick. Those who sleep more have been found to fight off viruses and infections faster than those who slept less—in animal studies, animals who slept more following an induced microbial infection showed an increased chance of survival.
Memory and Brain Function
One of the main functions of REM sleep is to help our brains process and save new information as memory. That’s actually a big reason why babies sleep so much—their sleep cycles are filled with way more REM sleep than that of an adult, because they need it to store all the incredible amounts of brand-new information they are exposed to. In fact, scientists think that a fetus in the womb may actually spend all of its time in REM as it develops brain function, because it plays such an important role in brain development and maturity. Additionally, deep sleep is the time when the brain is able to replenish its energy reserves – glycogen, which is stored in the brain as a “backup” to its primary fuel, glucose. A neurotransmitting chemical, adenosine, kicks in once these glycogen reserves are depleted, signaling the body to let you get the sleep you need to replenish brain glycogen.
Your hormones depend on healthy sleep to remain balanced. For instance, research shows that a single night of sleep deprivation causes elevated levels of cortisol, a stress hormone, during the waking hours the next day. Chronically-poor sleep invariably leads to chronically-poor hormonal balance and higher levels of stress. Good sleep and healthy hormonal balance are a two-way street—you can’t have one without the other. Sleep deprivation will cause an increase of stress hormones and the depression of anti-stress hormones, but the resulting hormonal imbalance itself perpetuates insomnia! So to restore healthy sleep, you must start by helping to fix this hormonal imbalance in other ways, such as through nutrition, and other specific therapeutic techniques which you will learn in this book. As you begin to get better sleep, your hormonal health will improve, allowing continued improvements in your sleep, too.
Anxiety and Mood Disorders
Chronically-insufficient sleep can lead to long-term mood disorders, and has been linked to depression, anxiety, and mental distress. Even while they do sleep, insomniacs have more muscle tension, a faster heart rate, and faster brain wave patterns in bed, which leads to a greater degree of mental stress and less-restful sleep. One study found that those who slept 4.5 hours per night reported feeling sad, stressed, angry, and mentally exhausted. (Sound familiar?) Another found that sleeping less than 4 hours per night led to declining levels of optimism and sociability. But all of these symptoms were found to improve dramatically when the subjects were able to regain a healthy sleeping schedule.
Metabolism and Obesity
When you’re sleep deprived, leptin (a hormone that signals satiety) falls, while ghrelin (a hormone that signals hunger) rises. A study found that people who slept only four hours per night for just two nights experienced an 18% reduction in leptin, and a 28% increase in ghrelin. This would explain why those who are trying to lose weight have a much more difficult time doing so when they don’t sleep enough. Another study showed that dieters who slept 8.5 hours per night lost 55% more body fat than those who only got 5.5 hours. In another study of people who were trying to lose weight, those who slept 6-8 hours per night lost an average of 10 more pounds than those who slept less. People who habitually sleep less than 6 hours per night are more likely to have a higher than average body mass index, while those who sleep 8 hours have the lowest BMI.
Diabetes and Insulin Sensitivity
Researchers have found that insufficient sleep may lead to type 2 diabetes by influencing the way the body processes glucose, the high-energy carbohydrate that cells use for fuel. One short-term sleep restriction study found that a group of healthy subjects who had their sleep cut back from 8 to 4 hours per night processed glucose more slowly than they did when they were permitted to sleep 12 hours. Adults who sleep less than 5 hours per night have a greatly increased risk of either having or developing type 2 diabetes, according to many epidemiological studies. This is likely due to the effect of insufficient sleep on the body’s glucose metabolism, which we’ll dive into later in this book. In one study, researchers found that subjects who had their sleep restricted from 8 to 4 hours per night processed glucose more slowly than they did when permitted to sleep 12 hours. Additionally, Inadequate sleep has been shown to affect insulin regulation, by causing an increase in the secretion of insulin following a meal.
There is a strong scientific correlation between poor sleep and both cardiovascular disease and stroke. For those who have hypertension, research shows that one night of inadequate sleep can cause elevated blood pressure throughout the following day. One study found that sleeping less than 6 hours significantly increased the risk of heart disease in women. Now that you see how important sleep is, make sure to take our Sleep Quiz and see what you can do to improve it.