How Much Sleep Do We Really Need?

Fluctuations in normal sleep patterns—even if it means getting more sleep— can lead to grogginess and lethargy.

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It's first period—or frankly, any period—and the urge to go to Terry’s and get an iced coffee to make it through the rest of the day is growing stronger. As Stuyvesant students who receive inadequate sleep, this experience is all too familiar. But sleep deprivation doesn’t always have us completely exhausted—in some instances, we actually feel more energetic. Investigations regarding sleep deprivation have debunked a common misconception about sleep.

Sleep is composed of five cycles, all of which are important to how we feel after we wake up and our brain activity throughout the day. The first stage, which occurs right before sleep, is called wake. People are still conscious during this period, and the eyes are either still open or beginning to fully close. Following this is N1, or light sleep, in which brain activities begin to slow down and the body starts to enter a state of full relaxation. An uninterrupted sleep is one that doesn’t spend too much time in N1 but rather moves onto N2 quickly, also known as deeper sleep. This third stage makes up about 45 percent of the entire sleep, in which there is a clear drop in heart rate and breathing. Our muscles relax and our body temperature drops. Moving on, the fourth stage is N3, or deep sleep. The body relaxes fully, and it is seen as the most important for bodily recovery. It’s characterized by low frequency and higher amplitude delta waves. Even with bodily functions slowing down during this period, it is evident that N3 contributes the most to brain activity in terms of creativity and memory. Lastly, our bodies enter rapid eye movement sleep (REM), which makes up about a quarter of our entire sleep. Our muscle movements become quite irregular and we are not as restful because we may be dreaming during this stage. Even so, REM sleep also contributes to many cognitive functions as our brain activity resembles that of when we’re awake.

All these stages are necessary for good sleep, but various factors including age, sleep disorders, sleep patterns, diet, and anxiety can impede this ideal sleep cycle. However, experiments conducted by neurophysiologist Marcello Massimini suggest that getting the suggested eight hours of sleep is not necessary to fully function. In fact, we may be able to function more efficiently when we don’t get enough, or less than the average six hours. According to his study in the journal Cerebral Cortex, the brain becomes more reactive and sensitive as the day goes on, while bodily reflexes may be noticeably sharper and more exaggerated. This same situation can be applied to many people, including Stuyvesant students. Though eight to nine hours of sleep is seen as the standard for adults and teenagers, when we receive less, we still feel energized. On the other hand, some people often feel lethargic when they sleep more than the recommended eight hours. Significant changes from our regular sleeping patterns, even if it means getting more sleep, may leave us feeling fatigued and moody throughout the day. Thus, it’s best to maintain a consistent sleep schedule.

Sleep deprivation carries many negative effects on cognitive function, along with that of the heart and the circulatory, metabolic, and immune systems. There are two types of sleep deprivation: acute, one to a few nights without sufficient sleep, and chronic, a consistent sleep deficit lasting multiple weeks or months. Even in relatively healthy adults, there are short-term effects of either type of sleep disruption, which include emotional distress, somatic pain, and far more memory and performance deficits. The long-term effects are more severe. These vary from hypertension, cardiovascular disease, metabolic syndrome, and colorectal cancer. The probability of these effects taking place is based on genetics and how consistently one is able to go through every cycle of sleep. If one wakes up feeling muzzy and groggy throughout the day, it’s a clear indication that they were disrupted in their sleep. If this is constant, they may even have insomnia.

In order to calculate how much sleep we need, we need to try to understand our personality and how we feel when it’s time to sleep. Asking yourself simple questions, such as whether you fell asleep easily or found yourself tossing and turning, can help you get a firm feel of your sleep rhythm and which patterns are best for you. Note how long it takes for you to fall asleep, or when your regular natural wakeup time is. Don’t try to sleep more or less than needed, but just the right amount. If you do find the best-fitting pattern and stick with it, your body will feel far more refreshed and you won’t need that cup of joe.