What does the sleep phase duration say about our sleep quality?

The sleep cycle: What the sleep phase duration reveals about your sleep quality

Our sleep takes place in several cycles, which in turn are divided into different sleep phases of varying duration. During the various phases, important processes take place in your body that help you to wake up refreshed and start your day full of energy. You can draw conclusions about the quality of your sleep based on how you feel when you wake up. If you wake up in a good mood, mentally fresh, and full of energy, that's a good sign. If, on the other hand, you feel dull, exhausted, and tired despite sufficient sleep, this indicates that your sleep is not optimal. Regular problems with falling asleep and sleeping through the night should not be on the agenda. But there is reason for hope: Your sleep looks different depending on the stage of life you’re in. As you get older, your sleep cycle changes, and you can influence the quality of your sleep yourself.

How long should it take to fall asleep?

One sleep cycle lasts about 90 to 110 minutes. This means that at normal sleep phase duration, you'll go through about five such cycles if you get the recommended eight hours of sleep per night. Each sleep cycle begins with the falling asleep phase. As you fall asleep, your body and consciousness transition from wakefulness to sleep. This sleep phase is characterized by a relatively short duration of just under 15 minutes. Sleep researchers have found that the falling asleep phase lengthens with age. While you fall asleep faster when you're younger, you need a little more time when you're a senior citizen. However, the difference is relatively small – less than ten minutes. If you notice that you need significantly longer than 20 minutes to fall asleep over a period of several months, this may indicate a sleep disorder. However, the reasons for this are often due to lifestyle factors. For example, if you consume a lot of caffeine, do strenuous exercise right before bedtime, or are emotionally upset, it takes you significantly longer to fall asleep. 

Light sleep: Is your sleep too shallow?

Falling asleep is followed by a phase of light sleep. During this phase, your muscles relax and brain functions slow down. Light sleep ideally makes up about half of a sleep cycle. The sleep phase duration becomes a little longer with each new sleep cycle. Even in the light sleep phase, your brain begins to process the experiences of the day. Overall, however, your sleep remains susceptible to disturbances, so you can wake up quickly during this phase. If you spend too long in light sleep and only a short time in the subsequent deep sleep, your body cannot recover sufficiently. Stress, alcohol consumption, or noise can negatively affect your sleep quality and cause your sleep to remain shallow. In this case, you should provide a quiet environment and avoid stimulants to ensure better sleep.

The deep sleep cycle and its importance for your sleep quality 

Deep sleep is especially important for physical regeneration. Thanks to the release of certain hormones, your immune system is strengthened, and your cells can renew themselves. At the same time, stress hormones such as cortisol have a particularly low level. A sleep phase duration of about one hour is normal for the first deep sleep phase. After that, deep sleep decreases a little with each subsequent sleep cycle. Because your body relaxes deeply during deep sleep, it is particularly unpleasant when you are awakened from this phase. You then feel really dizzy and probably need a few moments to wake up properly.

How much time should you spend in dream sleep? 

The last phase of a sleep cycle is the so-called REM sleep or dream sleep. As the most active phase of the brain, it offers your body the opportunity to dream intensively.  The total sleep phase duration of REM sleep should be about 75 minutes per night. If your sleep patterns are normal, dream sleep should get a little longer with each sleep cycle. Toward the end of the night, it can then last up to 15 minutes - the same amount of time as the falling asleep phase. Although the REM phase remains relatively stable in adults for most of their lives, this changes as they become seniors. In people over 60, dream sleep decreases.

Is there a perfect sleep cycle?

Per sleep cycle, light sleep should account for about 60 percent of your sleep, while deep sleep and REM sleep account for about 20 percent each. But these values should be taken as a guideline, not as an absolute rule. The ideal sleep phase duration for everyone does not exist. Depending on your circumstances and life phases, your sleep will change - and that's perfectly normal. Even the fact that you sometimes wake up for a few minutes during your sleep phases is perfectly okay. In fact, on average, adults wake up about 10 to 30 times per night. They usually fall back asleep immediately within a few minutes, so this brief waking does not affect a healthy sleep rhythm. The next morning, the memory of these brief waking states during the night is usually also extinguished.

However, the situation is different if you are affected by a sleep disorder. In this case, the five sleep phases can no longer flow into one another without interruption, and the quality of your sleep deteriorates. Those affected often complain about an excessively long phase of falling asleep and not reaching deep sleep, which is why they feel mentally and physically exhausted the next morning.  To get back to the most restful night's sleep possible, you should pay attention to several factors. In addition to a relaxing sleep routine, these include a healthy sleep climate, a quiet environment and, last but not least, a comfortable bed with a high-quality mattress and a slat base that matches it. This way you create excellent conditions to enjoy a high quality of sleep.