Researchers say that seven to eight hours of sleep is ideal. However, science also knows that this is not true for everyone. Our genes also influence how much sleep we need. Some people feel fit, productive and balanced after six hours of sleep, others only after nine. If you still haven’t had enough after eight hours of sleep, you may simply need more time to rest – or maybe even less.
“Seven to eight hours is an optimal sleep duration for around 80 percent of the population,” explains sleep researcher Thomas Penzel from the Charité Berlin. The scientific director of the interdisciplinary sleep medicine center estimates that five to ten percent need less sleep and the same number need more sleep. You can find out which group you belong to using the holiday trick, which is explained in the text below.
Fatigue can be caused by external influences
However, tiredness can also be caused by a lack of restful sleep. External influences can be light or noise, but also worries or stress. Parents of small children in particular can often tell you how unrefreshed you can be in the morning if you have been woken up many times during the night.
Physical causes of fatigue
Penzel also mentions internal causes that can lead to fatigue, such as sleep apnea, difficulty falling asleep and staying asleep, or restless legs syndrome.
These deficiencies and illnesses promote fatigue
According to Penzel, persistent fatigue can also be related to illnesses such as cancer, Alzheimer’s or even colds, as people with such illnesses often need more sleep. Other causes can be:
a malfunction of the thyroid gland, iron deficiency, vitamin B12 deficiency, vitamin D deficiency, medications such as anti-allergics, too little fluid, diabetes, too little exercise
It’s completely normal that we get a little more tired every now and then throughout the day, for example around lunchtime.
Reading tip: Vitamin D deficiency: symptoms, causes and prevention
What can help you not to be tired all the time
According to Penzel, anyone who struggles with persistent fatigue despite getting enough sleep can first try to get this problem under control themselves. For example, it is important for a restful sleep to to move sufficiently. The sleep researcher also advises to eat right. This includes not eating too heavily in the evening and eating your last large meal at least two hours before going to bed. A power nap in the afternoon can also help. “However, it shouldn’t last longer than 30 minutes,” says Penzel – otherwise the quality of sleep at night can suffer because you are not tired.
If you can’t fall asleep in the evening and find it difficult to get going in the morning, it can help to “reprogram” your internal clock. “It is helpful to turn down the lights earlier, stop exercising in the evening and relax before going to bed.” Regular bedtimes can also help you get a restful sleep.
On the other hand, very exciting films in the evening or awakening substances such as coffee are counterproductive.
Fall asleep faster with Meßmer Sleep Beautiful Tea
Herbal tea with lavender flowers and valerian
Find out how much sleep you need
It can also be helpful to find out how much sleep your body actually needs. You can, for example, take advantage of a longer vacation, recommends the psychologist and sleep researcher Hans-Günther Weeß in his book “Sleep works wonders”. It’s best not to set an alarm for two weeks and see how many hours of sleep you wake up after in the second week. The results in the first week of vacation are less meaningful because you may sleep longer due to exhaustion. Once you know how much sleep your body needs, you should make sure you give it this time in your everyday life.
If none of the tips help, it is advisable to consult a family doctor or sleep doctor. Anyone who generally cannot stay awake for more than three hours should definitely consult a doctor.