What happens while we sleep?
Our inner 24-hour body-clock, the so called circadian rhythm helps us to fall asleep by controlling important hormones. While the "awake" hormone Adenosine will be broken down during sleep, Melatonin really puts us to bed by making sure we feel drowsy and tired. But also the beginning of darkness tells our brain that it is time to get some rest. A night of sleep is characterised by REM sleep (rapid eye movement sleep) and non-REM sleep (which has four stages). Sleep intensity increases from REM sleep, which is the lightest form of sleep to non-REM sleep, the deep slow-wave-sleep (Stage 4 of non-REM sleep is the deepest sleep stage).
Sleep to memorize
As soon as we fall asleep, our brain has time to restore and order itself. Newly learned information and skills are consolidated. That means if we do not get enough sleep, we have trouble learning and remembering newly acquired information. Especially the restorative deep sleep, the slow-wave-sleep (SWS), is crucial for processing newly acquired information (declarative memory consolidation). One brain regions is especially important. The hippocampus replays information that has been learned during the day and therefore helps us to improve our skills. Thus a good night sleep improves learning and memory. Whether you are learning how to play the cello, windsurf, or trying to solve a problem that still puzzles you. A good night sleep will help. But not only learning and memory are altered during sleep. Researchers recently found that sleep is crucial to renormalise overall synaptic strength, which was increased during wakefulness. Thus, sleep literally relaxes your brain, even up to a neuronal level.
Sleep to stay healthy
While we sleep our body can gain strength again. One important task of sleep is to battle inflammations in our body. Inflammations are linked to stroke, heart disease, arthritis, diabetes, and premature aging. Researchers indicated that people who sleep less (six hours per night or less) have higher levels of inflammatory proteins in their blood (C-reactive protein) due to metabolic dysregulations, which were associated to heart attack risks.
Sleep to lose weight
But sleep does not only make sure that we stay healthy. Sleeping also helps to lose weight when we are on a diet. Researchers of the University of Chicago found that dieters who had slept enough lost more fat (56% of their weight loss) than those who were sleep deprived. Interestingly, those who had not slept enough lost more muscle mass. Dieters in the study also felt more hungry when they got less sleep.
Sleep against wrinkles
Indeed, Beauty sleep does exist. You may have noticed it already but during sleep, collagen levels are increasing. More collagen means that the skin is plumper and less likely to wrinkle. Thus sleep deprivation can cause wrinkles and having enough sleep will reduce your wrinkles.
When it comes to our health sleep has an important effect on our health especially all that involve our heart or blood vessels. Sleep can reduce levels of stress, thus people can have better control of their blood pressure. Furthermore sleep has an effect on cholesterol levels, which play a significant role in heart disease.
To sum it up, sleep makes us more alert, more energetic, we are functioning better and feel happier. Sleep does not only increase learning, helps you lose weight and reduces stress but also helps to tackle the everyday challenges of life. If we sleep longer we feel stronger and stay mentally and physically healthy.