Everyone knows the expression, "I need my beauty sleep." But what is actually happening to your body during the different phases of sleep?
At night, the hormonal balance is regenerated. During deep sleep, the body releases a lot of growth hormones in particular, which allow muscles to grow and tauten the skin, among other things. Deep sleep phases are very important for athletes who need to build or maintain muscle. Exercise increases and intensifies the deep sleep phases, which in turn improves athleticism. The only thing to remember is to not exercise too late in the day, as it is more difficult to fall asleep when the body is overheated.
The nightly release of growth hormones is also important for the skin. The basic framework of the skin, which is key for youthful firmness and elasticity, is made up of the connective tissue protein collagen, which is also primarily formed and regenerated under the influence of the growth hormone. Without sleep, and in particular deep sleep, the skin can age more quickly and lose its tone and elasticity prematurely.
In addition, various hormones are released during sleep that regulate hunger and body weight. The neurotransmitters involved here include leptin, ghrelin and insulin. Leptin is the hormone that decreases the appetite. During sleep, the leptin level is usually so high that there is no feeling of hunger. However, interrupted sleep means that this level is reduced at night, which leaves you with a feeling of hunger and appetite although the body does not actually need any nutrition.
Ghrelin, on the other hand, stimulates hunger and appetite and is usually low during sleep. If you do not sleep well and lay awake at night, you will feel hunger, particularly for carbohydrates. This in turn leads to the release of insulin, and an increased insulin level leads to a flow of calories into the body's cells. This also increases the risk of contracting diabetes.
The effects of sleep on the body are therefore extremely positive. Those who sleep well can certainly refer to the phrase "beauty sleep".
Source: Schlafen für Aufgeweckte, Dr. med. Michael Feld, 3. Auflage 2015