After exercise, most people are short of water and it is easy to drink too much water. If you drink too much water at one time because of thirst, it will reduce the salt content in blood and the osmotic pressure of cells, leading to imbalance of sodium metabolism and muscle spasm. Due to the insufficient blood supply to the gastrointestinal tract during strenuous exercise, the function is not good, and the absorption capacity of water is weak, and too much water penetrates into cells and intercellular space. Brain tissue is fixed in a hard skull. The swelling of brain cells will cause the increase of brain pressure, which will lead to the symptoms of "water poisoning" such as headache, vomiting, lethargy, blurred vision and slow heart rhythm.

For obese people, drinking water quickly at one time will quickly dilute the blood and increase the burden on the heart. After exercise, this situation will be more serious.

In addition, if you are overloaded with aerobic exercise to lose weight, drinking water is the most taboo in the whole process. Drinking water before exercise is easy to cause stomach pain, and drinking water during exercise is easy to vomit. Drinking water immediately after exercise, especially cold water, is very harmful to the stomach.

Drinking water before and after exercise is subject to dry mouth and throat.