6 Things You Need to Know to Hack Your Sleep
Years ago, I saw in interview with Rudy Giuliani, back in the early 2000s when he was “America’s Mayor” (i.e., not whatever the hell it is he has turned into now), and he shared that he had trained himself to function on less sleep. I thought this was amazing and started to do the same thing. I imagined all of the things I could do if I only needed to sleep 4 hours a night. That would give me an extra 4 hours a day, 28 hours a week, more than 4.5 extra days a month, 56 extra days a year, and you can see where I am going with this. Unfortunately, and perhaps Rudy is a good example of this, not getting sufficient sleep can seriously impair brain function.
1. Why do we sleep?
Scientists still do not know exactly why we sleep, though they know we need to and without sleeping our bodies would eventually shut down in die. Now fortunately, most of us are going to lay down and fall asleep before that happens, but insufficient sleep is still recking havoc on our brains and bodies. Our brains and bodies need to sleep because they are hard at work during that time performing functions that are not possible during our waking hours.
2. Sleep Stages
During the night, we pass through a 5 stage sleep cycle that includes drowsiness, light sleep, moderate sleep, deep sleep, and rapid eye movement (REM) sleep. We cycle through these stages multiple times a night, cycling roughly every 90 to 110 minutes and spending about half of the total time in stage 2 sleep, about 20% in REM sleep, and the remaining 30% in other stages.
The first stage is considered “light sleep” as we drift in and out of sleep and are easily awakened. When we enter stage 2 sleep, our eye movements stop and our brain waves (fluctuations of electrical activity that can be measured by electrodes) become slower, with occasional bursts of rapid waves called sleep spindles.
Stages 3 and 4 are referred to as deep sleep. In these stages our brain waves drop in to the “delta” range (i.e., slowest brain waves) and our bodies are completely immobilized. When we are awoken during this stage it takes us a moment to adjust and we feel groggy and disoriented. During the final stage, REM sleep, our breath rate increases as does our heart rate. Our blood pressure rises, our eyes jerkily move in various directions, and our limbs are temporarily paralyzed. The time we spend in deep and REM stages of sleep appear to be particularly beneficial in terms of cognitive (i.e., deep sleep) and physical (i.e., REM sleep) recovery and functioning, topics we will discuss further below.
3. Sleep and Circadian Rhythms
Mental and physical changes that occur over the course of the day are referred to as circadian rhythms, coming from the Latin word for “around the day.” We often refer to these changes as being dictated by our “biological clock.” This is more than a metaphor, however. These biological circadian rhythms are governed by a structure in the hypothalamus (i.e., the part of the brain that regulates body temperature, thirst, hunger, and other homeostatic systems) called the suprachiasmatic nucleus or SCN.
Light travels from photoreceptors in the retina, along the optic nerve, to the SCN, which then relays these signals to several other areas of the brain including the pineal gland. The pineal gland then responds to changes in light by turning on and off production of melatonin, an important hormone for sleep.
Melatonin levels naturally increase in response to darkness (i.e., when the sun goes down) and this system has worked beautifully for tens of thousands of years. The problem is that for the last 100 years of so, a rapidly growing percentage of the worlds population have lived in conditions illuminated by artificial lights. And in the past 20 years this has included a growing number of florescent and LED lights, including the lights coming from our digital devices, that emit unnatural levels of white and blue spectrum lights and signal to our pineal gland that it is daytime, and it should stop producing melatonin. You can see where we are going. Our modern illuminated life is messing with our biology and our sleep.
Disruptions to our circadian rhythms can have a significant impact on our functioning over the short-term, such as when we experience jet lag, but the effects are even more dire over the long-term. This is something experienced by many “shift-workers” whose work scheduled contradict their biological clocks. These workers are at increased risk of heart disease, digestion problems, and mental health issues stemming from their sleep problems.
4. While You are Sleeping
Our brains do not “turn off” when we sleep. In fact, our brains are very much “turned on” and very busy performing vital functions while we are asleep. One of the most fascinating discoveries over the past few years is that the brains glymphatic system is hard at work clearing toxins in the brain that accumulate during the day. The space between neurons expands while we sleep, ushing in cerebrospinal fluid to clear out the waste that has been accumulating, including β-amyloid protein, a precursor to the plaques that cause Alzheimer’s. In addition, microglia, which are released in response to infection in the brain, are also activated during sleep to repair normal wear and tear that occurs during waking hours. And this process too plays an important role protecting us from cognitive decline. This also suggests that biological mechanisms that govern our sleep-wake cycles also play an important role in turning our immune system on and off.
5. Sleep and Cognitive, Emotional, and Health Factors
While we do not yet know exactly why we sleep, animal studies suggest that without sleep our immune system is soon impaired and sleep deprivation may lead to premature death. Sleep also appears necessary for neurological functioning. Insufficient sleep not only leaves us drowsy but impacts our ability to concentrate, remember, and perform complex operations (e.g., math operations). It also impacts mood regulation and may lead to hallucinations. Without necessary restful sleep, brain cells may become depleted of energy and cellular byproducts may contribute to neural malfunction. Sleep may also serve as a time for strengthening neural connections that, without sleep, may atrophy and die off.
Sufficient sleep is associated with improved cognitive functions including memory (i.e., retention and recall of information), attention (i.e., focused and sustained concentration), working memory (i.e., mentally managing multiple pieces of information needed to execute tasks), and other executive functions (i.e., planning, organization, self-monitoring, as well as emotional and behavioral regulation). Studies also suggest sleep is associated with creativity. While poor sleep seems to have an adverse impact on creativity and out of the box thinking, sufficient sleep is associated with improved divergent thinking (i.e., seeing connections between disparate pieces of information and solving problems in novel ways).
Sleep also appears to be intimately intertwined with our mood. Sleep problems, either too much or too little, are often experienced by those with depression and anxiety. And for many of these individuals, when sleep is corrected symptoms of depression and anxiety resolve without further treatment. This may be due to the fact that parts of the brain governing our sleep-wake cycle, and associated neurotransmitters (e.g., serotonin), are also implicated in mood disorders.
Of course, it is not just our brains that are impacted. Poor sleep effects our bodies as well and is associated with numerous physical disorders, many of which are tied to inflammation, including increases in cortisol and thyroid hormone as well as poor glucose regulation, obesity, heart disease, diabetes, and cancer.
6. Hacking Sleep
A growing number of people, including children, seem to be taking over the counter melatonin supplements to counter act sleep problems. Unfortunately, these substances can build up in your body and their long-term use can result in increased tolerance (i.e., requiring larger doses to achieve the same effect) and other problems. Because the effect of these supplements are still unknown, many sleep experts discourage their overuse.
So, what can we do? Since sleep and wakefulness are influenced by different neurotransmitter signals in the brain, foods and medicines that change the balance of these signals affect whether we feel alert or drowsy and how well we sleep. And a number of lifestyle factors influence the quality of sleep we experience. Caffeine, stimulant drugs, nicotine, and exercising late at night all impact our ability to fall asleep. And alcohol (i.e., a “night cap”) may help us to fall asleep but robs us of restorative deep and REM stages. And as noted above, fluorescent light bulbs and blue light emitting devices (i.e., smart phone, tablet, computer, and television) send signals to our pineal gland (i.e., responsible for melatonin production) that it is still daytime and delay the onset of sleep.
The antidote to some of these factors is obvious. Do not drink coffee in the afternoon or evening, refrain from drinking alcohol, and exercise early in the day. Others may not be as obvious. It is important to have black out blinds and even blackout take for the lights on electronic devices in the bedroom (e.g., television, cable box, modem, etc.). Ideally, you are not using LED or florescent light bulbs in the house but if you are, be sure to dim them in the evening. And if being on a blue light emitting device for two hours leading up to bedtime is necessary, then use an app like F.lux or Apple’s Nightshift to not only turn down the brightness of the light but turn down the blue light and increase warmer tones. Other environmental factors such as a comfortable but firm mattress, complete darkness, and a quiet environment are helpful as are consistent sleep times and bedtime routines.
The amount of sleep we require decreases with age (i.e., young children require more sleep than adults). The exact amount of sleep people require, however, varies and the quality of sleep at night may be more important than the total time. I have recently started tracking my stress and recovery (i.e., sleep) using the Whoop and it has been a game changer. While I could always feel the toll that insufficient sleep was having on my body (e.g., a chest cold that never went away) and brain (e.g., poor attention, memory, and executive function), Whoop analyzes the degree to which insufficient sleep is impacting me and determines the factors that may be contributing to poor sleep quality. As a result, I can optimize my sleep and even get more recovery in less time. With Whoop, I know what time I need to get to bed, what time I can wake up and still experience a high level of mental and physical functioning, and how to optimize the amount of time I spend in restorative deep (i.e., brain recovery) and REM (i.e., body recovery) stages of sleep. For additional information on role of sleep, check out the Sleep Association at www.sleepassociation.org.
