Do you often wake up feeling like you have not closed your eyes? What you sometimes think of as insomnia is in fact linked to a lack of deep sleep. This phase is the key to restorative nights. People who suffer from sleep disorders – and who suffer fatigue and mood do not actually dive in deep sleep enough.
Sleep can be broken down into two phases: slow sleep and REM sleep. The slow-paradoxical cycle lasts about 90 minutes and is repeated over the duration of the night.
Each phase consists of several parts. Slow sleep is done in four stages: falling asleep then three periods of deep sleep (the first two being slow-deep sleep). Paradoxical sleep, on the other hand, is that of dreams. It is lighter, it is of variable duration (it lasts longer and longer as the night goes on). During the paradoxical sleep, the muscles are totally relaxed but the brain is very active: we talk about releasing the nerve pressure (like a pressure cooker) and thus a total relaxation of the muscles so as not to have energy expenditure and risks of accidents during this letting go.
The longer the waking time, the longer the slow-deep sleep must be. This will be to the detriment of paradoxical sleep (since it is preponderant especially in the duration of sleep). If the duration of sleep is too short, slow-deep sleep will be reduced accordingly, drowsiness is there (therefore lower alertness, slowed movements, so less productive training exercises).
Sports training delays the onset of sleep (exciting hormones do not stop immediately, body temperature does not drop fast enough). So if the training takes place late at night, there will be maladjustment of the clock biology, thereby reducing the quality of sleep. Finally, the amount of training must be fair. Indeed, over training induces many changes in the body, including sleep disorders.
What happens during the 8 hours of the night to allow the body to recover? Classic slee, corresponds to three quarters of the night’s time, about 6 hours for an 8-hour night.
A 13-year study showed that adults who slept little had higher BMI and more fat than those who slept enough. During sleep time, a chemical called leptin is released, cutting off the appetite. Sleep deprived adults show cravings for sweet foods. You have realized that when your night has been short, you only think about eating. During a night of sleep (8 hours), you burn between 272 and 416 calories depending on your weight.
Deep sleep is therefore important to prevent fatigue and avoid disturbances of the body. It is scientifically established sleep disorders increase the risk of diseases, such as type 2 diabetes and obesity.
