What your body does while you sleep

With the current pace of life, more and more busy (so many things to do!), Sleep may seem quite unproductive, but just because you are not awake does not mean that things are not happening in your body.

During those 6, 7 or 8 daily hours of sleep we go through different stages of sleep in which we already know that if we wake up during the first stage we will feel like we have not slept at all. Right at this stage is when it is easier for us to wake up. The muscles relax and the slow eye movement begins.

The second stage is what Philip Gehrman, assistant professor of psychiatry at the University of Pennsylvania (USA), says is the "average dream", where we spent half of the night. In this stage the brain waves are slow -with some rapid variations- and both our heart rate and blood pressure become slower and irregular. This means that, for much of the night, the heart and vascular system is receiving a much-needed rest, which could help explain the many cardiovascular benefits of sleeping.

So, in short, in this second stage: our breathing and our heartbeat become regular, body temperature drops, we lose the sensation of where we are, the brain waves become slower and the movement of the eyes stop. A little later, the blood pressure drops and the muscles relax even more.

The third stage is our deepest dream, and that is when our brain waves are transformed into restorative waves, slow and of great amplitude. Practically most of our bodily functions slow down during this time and our bodies begin to repair themselves. The energy is restored.

It is also the phase in which people walk asleep, talk or eat.

REM sleep is where we experience vivid dreams. Some experts often call it "paradoxical dream" because the body is out of action while the brain lit up as if we were awake. And, yes, during this time we also experience a rapid eye movement (which gives its name to this stage, rapid eye movement, REM). Muscles are paralyzed and breathing and heart rate can vary a lot.

In this stage the release of hormones occurs. So, for example, according to the Hormonal Health Network, as we fall asleep - although experts are still not sure exactly when -, the digestive system release hormones called leptin (which inhibits hunger) and ghrelin (which stimulates hunger) balance. In the event that we do not sleep enough, this balance can be altered, which would explain why people with insomnia see their appetite affected.

Finally, at this stage our brain also blocks the memories and archives the information that was absorbed the previous day.

Although it is not always possible to sleep from 7 to 10 hours per night recommended by some experts, at least now we can appreciate what happens when we do it.