Introduction: Recently, a claim has been circulating online and on WeChat: "Drinking cool water on an empty stomach in the morning over a long period can lead to physical fatigue, chest tightness and shortness of breath, memory loss, and may even cause some fertility issues. The explanation is that the morning requires 'yang' energy to circulate qi and blood; drinking cool water on an empty stomach will suppress this 'yang' energy, damaging one's constitution. Even drinking warm water is not recommended."
In fact, this claim is not entirely accurate. Water is crucial for the circulation of qi and blood, and drinking it in appropriate amounts and at the right time will not affect this process. However, the assertion that "drinking cool water on an empty stomach will suppress 'yang' energy and damage the constitution" has some merit.
This is because the morning is when 'yang' energy begins to rise. At this time, drinking water on an empty stomach can stimulate intestinal peristalsis and prevent constipation. However, drinking cool water can create an adverse stimulus to the 'yang' energy of the internal organs, and over time, this is detrimental to health.
It is recommended to drink warm water after waking up—water that has been boiled and then naturally cooled to 30°C~35°C, which is generally not hot to the taste and does not irritate the stomach. Compared to cooled boiled water, warm water is closer to body temperature and is more easily absorbed by the body.
It should be noted that drinking too much water on an empty stomach in the morning is not advisable. A single glass is sufficient to achieve a health-promoting effect; otherwise, it can increase the burden on the gastrointestinal tract and hinder food digestion.