General

Concerning really sleeping through, sleep medicine and sleep psychology have learned. Because, sleep and sleep habits are very individual. It is just like in sports — in the end it is only the result that counts: winning or losing. When the sleep-well-indicators motivation, awareness, wakefulness, health and well-being are right, one can say out of experience that the parameters for sleep are right, too. Here, one or two hours less sleep is not having such a negative effect. Because, one hour awake per night sounds like a serious sleeping through disturbance. But, during centuries it was common to be awake for an hour during night. Out of this reason, waking up at night is not automatically something to worry about.

Amazingly, sleep and its habits are versatile: people are able to sleep in different places and at different times. And the time of being awake is just as versatile.

I am sure, you once have read Don Quixote. There is a remarkable point in the book: “Don Quixote obeyed nature so far as to sleep his first sleep, but did not give way to the second, very different from Sancho, who never had any second.” Probably, you just have overlooked this scene like the most of us. But, Roger Ekirch, a Historian of the Virginia Tech University, was very interested in exactly this scene and he could not forget the quote: “first and second sleep”. So he researched in dramas, treatises, diaries and finally found more than 500 different quotes that made it clear to him: The human being used to sleep in two blocks of about four hours for centuries. And in between he lied awake for an hour! This hour was no agonizingly tossing and turning like it is described nowadays. In reality, it was some kind of daytime: people read, told stories, visited neighbours. Scholared spirits even recommended this hour for productive studies, doctors for creating children and the church for praying. A whole range of prayer books were dedicated to just this nightly hour awake.

Then, one invention steeped in history put a sudden end to this familiar rhythm: the electric light made the light bulb shine and the human being started to prolong his day wide into the night. More and more activities were delayed to the later evening and there was no longer time nor strength for the nightly hour.

That these medieval sleeping habits might have been more than just a historical anecdote was suggested by experiments. US sleep scientist Thomas Wehr let test persons spend daily 14 hours in complete darkness. After several weeks, a pattern very close to the medieval descriptions showed. The tested persons divided their nightly sleep into two phases – with a break of one hour, which they spent in a very relaxed state. But, you don’t have to worry: the modern society is not likely to quickly let go of the habit of the so-called “one-phase-sleeper” or “block-sleeper”. Our problem is rather the lost sleep and the therefore arising accumulated sleep debt.

There are good news when it comes to sleep optimization: when you are ready to adjust your wake-sleep-dream-life to your inner and non-alterable clock, with necessary discipline and persistence it takes about 21 days until gradually the proper rhythm arrives again.

Example: Free-Nature-Camping

It is no doubt, most of us are out of their natural rhythm. That it is much easier to even out than one would have thought, is shown by an investigation conducted by the University of Colorado, Boulder.

The motto was: “Free-Nature-Camping!” More sunlight, less electric light. With this simple recipe, sleep disturbances and their consequences for health can easily be mitigated, like US-scientists prove. Their study has shown that it can be reached with just one week of camping vacation in the nature. Above all, when camping, the abundant sun- and day-light is quickly adapting the inner clock of the human being to the natural day-night-rhythm again.

First, Kenneth Wright and his team of the University of Colorado, Boulder, recorded¹ the sleep- and night-rhythm of eight grown-ups for one week while they were living their normal life. The worked, studied, went out in the evening and decided for themselves when they slept for how long. Following, the group spent one week with camping in the Rockies. The participants had no electric light and mobiles, torches or other electrical devices were not allowed.

In the beginning, the sleep behavior was not surprising: During the first week, the test persons went to bed late on average –- after midnight –- and got up later –- around eight o’clock in the morning. Like expected, they got less sunlight during the first week but more than usual in nature after sunset.
What was surprising were the consequences: the inner clock of the test persons went two hours late in electric lit surroundings. This was visible in the level of the sleeping hormone Melatonin. This hormone participates in the regulation of the day-night-rhythm. The level is rising on the onset of darkness and it makes us sleepy, light slows down the production of the hormone in the morning and rings in waking up. During the first testing-week the Melatonin level rose in the late evening, about two hours before onset of sleeping. In the morning, the level diminished only when waking up at about eight o’clock. This also explains, why a lot of people in our modern society are feeling weak and tired in the morning. The biological night — characterized by a higher Melatonin level –- is reaching into the day, so to say.

Already after one week of camping, the clock adjusted to the natural day-night-rhythm. The Melatonin level began to rise at about sunset. In the morning, it decreased right after sunrise, even before the test persons woke up.

Under natural light, even the chronobiological “owls” got to early “larks”. The sleeping time total stayed the same in both weeks. The adaptation to the natural rhythm automatically led to a healthier and above all more recreational sleep!

^1: Original Paper of the Scientists: Kenneth Wright (University of Colorado, Boulder) et al.: Current Biology, doi: 10.1016/j.cub.2013.06.039

One or two glasses of red wine may quite relax and have a soporific effect. Possibly, Italian scientists have discovered the reason why. Some of the most popular red wine grapes surprisingly contain the sleeping hormone melatonin in their peel, like botanists found out.

Especially Nebbiolo, Croatina, Cabernet Sauvignon and Sangiovese – one of the main grapes of Chianti – were abundant with Melatonin. Experts reckon, that only a small amount of alcohol is soporific, by no means it should more than 0.2 liters of wine.

On the other hand, it ain’t easy for people who smoke. The “blue fume” increases the risk for cancer and cardiovascular diseases and weakens the immune system. In addition to that, besides caffeine nicotine is an antagonist to the sleeping hormone melatonin and in long term, may lead to a chronical lack of melatonin. Furthermore, statistics have strengthened the thesis that smoker more often suffer under sleep disturbances and therefore start less rested in a new day. US-scientists have proved this with a study.

The scientists of the John Hopkins University, Baltimore, registered the sleeping phases of 40 smokers and 40 non-smokers and compared their sleeping patterns. The following day, the test persons were asked to give their own sleeping-impressions. Result: The smokers didn’t have such a deep sleep and did not feel recreated in the morning. Possible reasons might be the stimulating effect of nicotine and withdrawal symptoms during night.

A restful and sufficient amount of sleep helps the memory to save course contents during nighttime to retrieve them afterwards more easily. But of course, the old hint to put your documents under your pillow and hope that the content is wandering into your brain by itself is a fairy tale. “But, experiments of brain science again and again have proved the fact that we do need sleep for learning”, so the Austrian sleeping expert and Author Dr. med. h.c. Guenther W. Amann-Jennson.
 
Learning is not going to go astray
In the so-called non-declarative memory we are saving our knowledge about how we are doing certain things, for example how to enter key combinations, play an instrument or execute certain movements in sports. For example, when learning to present a poem in front of an audition most of the people do better after sleeping than before. “But, you have to have learned and exercised properly before the sleep has the desired effect”, emphasizes Amann-Jennson. Contrary to the non-declarative the declarative brain saves every knowledge contents. We need it for special learning contents like data, vocabulary, autobiographic or general knowledge that can’t always be connected with certain occurrences.

During sleep, the learned things get consolidated in the brain by getting securely anchored in the memory-processors. During alertness, the processes of absorption and decoding of new knowledge overlap. These permanent new inputs that stream in the brain, erase fresh memory traces that are not yet definitely anchored, again. The sleep supports the anchoring of the learned in that way that new contents can’t directly be absorbed neither by the declarative nor by the non-declarative memory. After a recreational sleep, the contents directly learned before can be recalled without effort. Out of this reason one can say “learning during sleep”.

Healthy sleep is the most important
Healthy sleep is characterized by falling asleep within 10 to 15 minutes, sleep through without big phases of alertness, and wake up after 7 to 8 hours of sleep, recreated and strengthened. Here, sleeping cycles are playing a decisive role. Only the one who really sleeps high quality is going through the single sleeping phases from light to deep sleep and REM-sleep 4 to 5 times per night. One cycle lasts about 90 minutes. “During deep sleep, rather vocabularies are dealt with, during REM-sleep movement patterns”, explains the sleeping expert. For saving into long-term memory several nights with sufficient sleep have to follow. Only then all jigsaw pieces become to one picture. “Another remarkable thing is: suddenly you find a solution during sleep you couldn’t think of during alertness. Whatever you want to learn, it is decisive to recreational sleep the following nights”, he further underlines.

Out of this reason, it is not advisable for students to learn the night through. Better learn intensely during the most effective time – with most people from 10.00 to 12.00 a.m. and from 4.00 to 8.00 p.m. – and process and consolidate the new knowledge during sleep. In this context it is remarkable that highly gifted people sleep particularly much. It is said, that Albert Einstein for example slept up to 12 hours a day.