People's sleep is rhythmic, and deep sleep and shallow sleep are repeated alternately until they are awake. The first half of sleep is mostly deep sleep, and the second half is mostly shallow sleep. When people sleep for a long time, deep sleep does not increase, but only prolongs the time of shallow sleep. People who can fall into deep sleep quickly, even if the light sleep time is short, will not affect their mental state; On the contrary, it only extended the shallow sleep time, and the quality of sleep did not improve. After getting up, I still felt "unsatisfactory".
Sleeping too long is not good for your health. Sometimes the side effects of 9 hours' sleep are greater than those of 6 hours' sleep. The longer and shorter sleep time will increase the risk of diabetes, coronary heart disease and even death, while 7 hours of sleep has the lowest risk of diabetes, coronary heart disease and death.
Sleeping too long can not only eliminate fatigue, but also bring a lot of harm to human body.
1. Weak. When people are active, their heart beats faster, their myocardial contractility increases, and their blood output increases. When the human body is at rest, the heart is also at rest, and the heartbeat, contractility and blood volume decrease. If you sleep for a long time, it will destroy the law of heart rest and exercise, and the heart will rest repeatedly, eventually making the heart contract weakly. A little activity, the heartbeat will be different, flustered, tired, so we have to lie down again, forming a vicious circle, leading to physical weakness.
2. Susceptible to respiratory diseases. The air in the bedroom is dirtiest in the morning. Even if the window is not locked, some air will not circulate. Dirty air contains a lot of bacteria, viruses, carbon dioxide and dust, which has an impact on the disease resistance of respiratory tract. Therefore, people who sleep behind closed doors often have colds, coughs and sore throats.
3. Physical fatigue and weakness. After a night's rest, muscles and joints will become slack. Exercise immediately after waking up can increase muscle tension, increase blood supply to muscles, make bones and muscle tissues in a state of repair, and eliminate metabolites accumulated in muscles at night, which is conducive to the recovery of muscle tissues. People who sleep late miss the opportunity to move because of muscle tissue, and feel weak legs, lumbosacral discomfort and general weakness after getting up.
4. Affect the digestive function. People who are lazy in bed can't eat on time, and the gastrointestinal tract is hungry and peristalsis, which disrupts the law of gastric juice secretion and affects digestive function.
5. Obstruct the function of the nervous system. People who sleep late are in a state of excitement for a long time, while other nerve centers will feel groggy and listless because they are depressed for too long and their recovery activities will become relatively slow.