When people wake up in the morning and drink a glass of water, they tend to prefer cold water or what is commonly referred to as 'room temperature water' based on their constitution.

Of course, the temperature of the water consumed after exercise and during meals can vary depending on individual constitution and condition. However, there are several reasons why lukewarm water is claimed to be better than cold water.

In particular, when considering the effects on health and digestion, many believe that lukewarm water may be more advantageous. Here are a few reasons:

Aids Digestion
Lukewarm water can help with digestion without irritating the stomach. Cold water can cause the stomach muscles to contract, reducing digestion efficiency, so it is known that lukewarm water is better, especially right after meals.

Regulates Body Temperature
Drinking cold water can rapidly lower body temperature, which may cause the body to expend energy to readjust the temperature. Lukewarm water is absorbed quickly at a temperature similar to that of the body, so it does not put a strain on body temperature.

Blood Circulation
Cold water can temporarily constrict blood vessels, hindering blood circulation. In contrast, lukewarm water may help to dilate blood vessels and promote smooth blood circulation.

Prevents Dehydration
Drinking cold water suddenly can cause a rapid change in body temperature, which may not be effective in preventing dehydration. Lukewarm water is absorbed more easily by the body, allowing for more effective hydration.

The stomach reacts differently to cold and warm water, which can affect digestion. According to experts, the temperature of water can also influence blood circulation and even symptoms like headaches. Additionally, drinking lukewarm water may actually reduce the feeling of thirst.

However, drinking cold water may be beneficial on hot days or after exercise. "Cold water is refreshing and useful during exercise or when body temperature rises," say clinical researchers. Therefore, it may be advisable to carry an ice water bottle after exercising.

The recommended amount of water to drink in a day can vary based on individual health status, activity level, climate conditions, and other factors. However, general guidelines can be provided.

The recommended water intake for an average adult is about 8 glasses (2.2 - 3 liters)

This is generally the average recommended water intake for healthy adults.

However, there are a few factors to consider:

1. Activity Level: If you exercise a lot or sweat heavily, you will need more water. It is important to replenish fluids after exercise.
2. Climate: In hot weather or humid environments, you may need to drink more water due to increased sweating.
3. Health Status: Water intake may vary due to certain illnesses or medications, so consulting a doctor may be necessary.
4. Diet: You also obtain some hydration through food. Fruits, vegetables, and soups are foods with high water content.

Ultimately, the best way to drink water is to drink when you are thirsty and to maintain a steady intake of water throughout the day. It is important to maintain a moderate amount, as excessive fluid intake can also cause problems.