Sleep phases and their importance – and how you can influence them for better sleep
A sleep cycle is divided into individual sleep phases. If you take a closer look at the respective sleep phase, you will understand its importance for our health and our overall well-being much better. Because it is the sleep phases, more precisely their frequency and quality, that determine how fit and relaxed we feel when our alarm clock rings – or not. Not only can we better understand our night’s sleep through the sleep phases, we can even influence them in our favour.
What are sleep phases?
Every night we go through a repeating sleep cycle or sleep cycles, in a quasi-continuous loop, until we wake up in the morning. Although the duration of a sleep cycle varies individually and from person to person, it usually takes between 90 and 120 minutes to complete a cycle. Accordingly, we “oversleep” about five sleep cycles every night, at least with an optimal sleep duration of seven to eight hours. A single sleep cycle includes multiple sleep stages. Sleep physicians divide a cycle into a total of four different and merging sleep phases, all of which are of great importance for restful sleep.
The four stages of sleep and their importance
A sleep cycle is divided into the falling asleep phase, the light sleep phase, the deep sleep phase and the dream phase. While at the beginning of our sleep the deep sleep phase takes up a larger proportion of the respective cycle, towards the end of the night it becomes smaller and the proportion of the dream phase increases. Apart from that, the sequence of the individual sleep phases is repeated again and again – and each one is determined by different characteristics and functions.
1st sleep phase: falling asleep phase
The falling asleep phase is the first sleep phase of a cycle and always initiates it. The body comes to rest, the muscles slowly begin to relax. Although we are not yet asleep at this stage, our pulse slows down a little and our breathing slows down. The falling asleep phase can also be recognized by slight muscle twitching, which can be traced back to the relaxation of the muscles. The falling asleep phase is extremely important so that we can even find our way into the sequence of our cycle. People who suffer from a sleep disorder often have problems getting into this phase of sleep.
2nd sleep phase: light sleep phase
The falling asleep phase finally turns into the light sleep phase. In this phase we are in a light sleep, external stimuli such as light or noise are perceived much weaker, even if they can still wake us up. Our body temperature drops, breathing becomes more even. Our musculature also continues to relax – including in the face, by the way, which can result in snoring or an open mouth. The light sleep phase makes up a large part of our nights. In the best case, it finally goes into the deep sleep phase.
3. Sleep phase: deep sleep phase
The deep sleep phase is considered to be the most coveted phase of a sleep cycle because, as the name suggests, this is where we sink into a deep sleep. External stimuli are hardly or not at all noticed during this sleep phase, and the body achieves a complete relaxation and resting phase. During this sleep phase, our breathing tends to be rather shallow. The activity of the brain, heart and circulatory system slows down, but many important regeneration processes are initiated and our metabolism also gets to work. Anyone who is woken up from a deep sleep usually feels exhausted and needs a long time to really wake up.
4. Sleep phase: dream phase
The fourth and final phase of sleep in a cycle is the dream phase, better known as the REM phase, where “REM” stands for Rapid Eye Movement stands. In fact, during this phase our brain is almost as active as when we are awake, and we dream – as can be seen from the rapidly moving eyes under closed lids. This phase is important for processing and sorting what we have experienced: what is stored in the subconscious can be brought to the surface in encrypted form in our dreams and processed in this way.
The REM phase is correspondingly necessary for our brain, our nerves and our psyche. In the dream phase, our breath deepens again, the cardiovascular system ramps up. Depending on the time, we can wake up completely from the REM phase or start the sleep cycle again. Do you have a very good memory in the morning of particularly realistic dreams? That’s because you’ve only just gone through the REM phase.
Why are sleep stages so important?
The description of the individual sleep phases already makes it clear how important each individual phase is for our sleep. The deep sleep phase in particular plays a key role in whether we feel physically and mentally rested. After all, our ingenious body is working on the regeneration of our cells, our organs and muscles during this phase. Possible viruses are fought, the immune system is strengthened. Our nervous system and our psyche also benefit from the body’s own processes.
Not only the deep sleep phase is extremely important, but also the REM phase, in which experiences are processed and sorted away. If our brain lacked the nightly REM phases, our mental state would be comparable to that of our apartment if we simply didn’t get to clean up for weeks. Depending on how well the individual sleep cycles can be completed within our sleep, we feel the next morning.
3 tips for a better sleep
Tip 1: Encourage falling asleep
In order for your body to find its way into the sleep cycles, you can help it to get started with the sleep phase. You can do this by helping yourself to calm down.
- Soothing teas, herbal sleeping pills or essential oils can calm the body and mind.
- You should ban screens with blue lights, such as smartphones or tablets, from your bedroom.
- Create a relaxed atmosphere with pleasant light sources and good air.
Tip 2: Allow good deep sleep phases
In the first half or usually in the first five hours of sleep, the deep sleep phases are the longest and most restful. Most people have their lowest body temperature between 3 a.m. and 5 a.m., which is the middle of the night. Accordingly, it is very helpful for sleep to go to bed on time. So, to enjoy the full five hours, ten o’clock in the evening is a perfect time to go to bed.
Tip 3: Watch the end of a REM phase
When your alarm clock wakes you up from one of the sleep phases, in the worst case a deep sleep phase, you feel like you have been exhausted. However, if you wake up after a completed sleep cycle, i.e. after a REM phase, you feel well rested and fit. So experiment a little with your morning wake-up time, as little as ten minutes earlier or later can make a huge difference – as long as you always go to bed at the same time in the evening, of course.