Along with exercise and nutrition, sleep is an essential component of well-being. No matter how much hustle and productivity we may try to pack into our days, sleep is a necessity that we can’t go without for too long. Because we spend an average of one third of each 24-hour day sleeping, it makes sense to prioritize good rest.
As you sleep, you enter a few different “stages” where your brain and body move through various processes of rest and restoration. Read more about these sleep stages and learn which sleep stage is most important.
The Benefits of Sleep
Amazingly, according to the National Institute of Neurological Disorders and Stroke, scientists still aren’t sure of the exact purpose of sleep. We know some of the physical processes that occur, such as reduced breathing and heart rates, and we also know that we dream, but the science behind why we need sleep or have dreams remains a mystery.
Scientists know more about the ill effects of too little sleep, such as diminished nervous system functioning, a shorter lifespan, reduced immunity, and higher risks for health conditions including obesity, diabetes, and heart problems.
About Sleep Stages
We previously wrote a guide to sleep cycles. Here’s a refresher:
The body cycles through four different stages several times during sleep.
Stage 1: The lightest sleep stage that transitions you out of wakefulness and into sleep as the body and brain slow down.
Stage 2: A transitional phase before deep sleep where body processes slow down even more.
Stage 3: Deep sleep that leaves you feeling rested and refreshed when you awaken.
REM Sleep: Short for “rapid eye movement,” which happens during this phase, along with dreaming.
The first three sleep stages are known as non-REM sleep, or “quiet” sleep. The fourth sleep stage is usually called REM sleep or dreaming sleep. (While you can still dream during the other stages, the most vivid dreaming often happens during REM sleep.) Our bodies repeatedly cycle through all of these sleep stages every time we sleep.
The Most Important Sleep Cycle
Sleep quality is often discussed in terms of non-REM and REM sleep, and which is more important. When it comes to feeling rested and refreshed, scientists look to both the deep sleep stage of non-REM sleep (stage 3) and REM sleep.
According to Harvard Health, non-REM sleep is thought to restore the body, while REM sleep restores the mind. Therefore, it’s difficult to discern which sleep stage is most important, because more than one stage is vital to our well-being. However, we can prioritize getting enough rest to ensure we cycle through the deep and REM stages of sleep. This is because the body undergoes processes that repair cells and tissues and support memory and immune functions, among others.
There is still much to learn about why we need sleep and what specific processes occur while we’re in dreamland. Scientists have discovered that each person’s individual need for sleep is unique and may be influenced by genetics and age. A good rule of thumb is to notice how rested, alert, and energetic you feel each day–if you feel that you’re mentally or physically sluggish, you might need more shuteye. If you’re concerned about whether your sleep may be impacting your physical or mental health, see your healthcare practitioner.
If you’ve ever had a bad night’s rest or stayed up all night studying, you know first-hand the effects of missing out on adequate sleep. Whatever your individual need for rest, it’s important to ensure you sleep long enough to fall into both the deep sleep and REM sleep stages each night.
