In the morning, people's blood concentration will be higher, and boiled water will be weak. Drinking a cup of boiled water after getting up in the morning has the advantages of preventing constipation, nourishing skin, health and longevity. Many people think that drinking light salt water is good for their health, so they drink light salt water in the morning, but this understanding is wrong. Studies show that people don't drink a drop of water during the whole night's sleep, but breathing, perspiration and urination are still going on, and these physiological activities consume a lot of water. If you get up in the morning and drink some boiled water, you can quickly dilute the blood and correct hypertonic dehydration at night. On the contrary, drinking salt water will aggravate hypertonic dehydration and make people more thirsty. Besides, morning is the first peak of human blood pressure rise, and drinking salt water will make blood pressure higher.

It is best not to drink juice, cola, soda, coffee, milk and other drinks in the first glass of water in the morning. Most carbonated drinks such as soda and cola contain citric acid, which will accelerate the excretion of calcium in metabolism and reduce the content of calcium in blood. Long-term drinking will lead to calcium deficiency. Other drinks have diuretic effect. Drinking them in the morning can not only effectively replenish the water that the body lacks, but also increase the body's demand for water, thus causing water shortage in the body. Drink water in the morning, it is best to drink the same boiling water as room temperature, and drink warm boiling water when it is cold to minimize the irritation to the gastrointestinal tract. It is found that boiled water cooled to 20-25℃ has specific biological activity, which can easily penetrate cell membrane, promote metabolism and enhance human immune function. People who are used to drinking warm and cold boiled water have higher deoxyenzyme activity in their bodies, good metabolism, less accumulation of lactic acid in muscle tissues and are not easy to feel tired. Be sure to cover the boiled water when it is aired the night before, because the boiled water will lose its activity if it is exposed to the air for too long.