Cold water & self depletion

   Water is necessary to our life. We can not live without water. How is it related to self depletion? Cold water, it has some of advantages. Cold water can be used for people to bathe in Winter. It helps to stimulate the circulation of blood and help your mind calm down and feel better. It also helps to strengthen the function of lung. It is same as cold water swimming. We can see most of people in USA or Europe, they like to drink the cold water in their breakfast, lunch and dinner or any kind of meals. It helps to let the temperature of your body go down a little bit and also after you drink the cold water, your heart, your body and your mind feel better when the weather is hot. Self depletion, for example, when you sleep a little bit last night, the next day you will feel sleepy and tired when you are at work. You can see the relationship between them. After you drink the cold water when you feel sleepy and tired at work, your body, your heart and your mind will not feel tired and sleepy. The cold water sounds like the same function as the drinks selling outside and it always in our life and we need to drink it when we feel tired and sleepy, it's call functional drinks. We can see them in our life such as Monster, Red Bull and so on. After we drink them, they can give us more energy our bodies need and we will not feel tired and sleepy. So the question is why the function of the cold water works same as the function of functional drinks for the people feel tired and sleepy, we still choose the functional drinks sometimes? Also, maybe the functional drinks have more calories and it will help you to be fatter.