At Careica Health, we’ve lost count of the number of times people have asked, “How much sleep do I need in a night?”
While we wish there was a magic answer that applied to everyone, the amount of sleep people need to feel rested varies from individual to individual.
While it’s recommended that adults get 7 to 9 hours of sleep per night, some need less, and some need more. Many people refreshed after 6 hours, while others may require 10 to take on the day. The quality of sleep you receive each night can also affect how many hours it takes to recharge.
In this blog, we’ll explore the 5 Stages of Sleep, and what happens to your body during each of them. Before we can look at the 5 Stages of Sleep, it’s important to understand what a sleep cycle is.
A sleep cycle progresses through the stages of non REM (rapid eye movement) sleep to REM sleep, and this cycle repeats several times during the night. A typical sleep cycle occurs every 90-120 minutes, resulting in four to five cycles per sleep time.
Essentially, a person goes from light to deep sleep, reverses back from deep sleep to light sleep, and ends with the REM cycle of sleep, before starting the cycle of light sleep all over again.
Now that we understand what a sleep cycle is, let’s explore the different stages of sleep, and how they impact your sleep experience.
For the majority of people, a sleep cycle begins with Stage 1 sleep, where the body begins to relax and feelings of drowsiness start. During the transition of being awake to falling asleep, people often experience muscle jerks or sensations of falling. Stage Two, when we are drifting off to sleep, is the easiest to wake up from.
Almost 50% of the time spent asleep is spent in Stage 2 sleep. During this stage, the heart rate begins to slow down and core body temperature decreases. Brain waves also slow down, and there is a frequent occurrence of brain waves called sleep spindles, which help you to stay asleep.
Stages 3 and 4
Stages 3 and 4 are the deepest stages of sleep and are the most difficult to wake up from. Stages 3 and 4 are periods of slow wave sleep which occur when your brain waves slow to what is known as delta waves. In these stages, blood pressure drops, breathing slows down and there is no eye movement. These stages of sleep are the most restorative, and you are less likely to be affected (and woken) by external stimuli. Take note that if you take a nap during the day and fall into a deep sleep, you may have difficulty falling asleep at night because your body’s need for sleep has been reduced.
The last stage of sleep, Stage 5, is the only stage where REM sleep occurs. REM sleep typically occurs 90 minutes after you fall asleep, and is usually where dreaming occurs. People generally experience three to five REM periods during sleep, with the longest period occurring right before waking up. During this stage of sleep, the mind re-energizes itself while the body is immobile. Breathing becomes shallower and blood pressure rises. REM sleep is considered to be extremely important as the brain exercises important neural connections, which are the key to overall health and well being.