When the weather is hot, people's mood is very irritable. Why?

To replenish water after summer exercise, from the health point of view, it is best to drink low-concentration (.9%) salt water. If you feel that the taste is not good, you can add some juice appropriately, but not cola.

With the coming of summer, the temperature is rising and people's activities are increasing. Doing more strenuous activities in this weather means that we will also sweat more, so how do you replace the lost body fluids? Do we really need to do this?

■ In summer, the human body is dehydrated

To the second question, our answer is yes. Susan Kreno, author of Energy Intake, said: "In summer, < P > most people are dehydrated to some extent." Therefore, we should drink 8 to 12 cups of liquid every day, and Kreno suggested that at least 5 cups of pure water should be drunk. Kreno explained that every hour of exercise will make your body lose about 4 cups of water. The exact number depends on your weight, amount of exercise and speed of exercise. When exercising in mild weather, people will lose 1 to 2 quarts of body fluids every hour due to perspiration. The more intense the exercise or the higher the temperature, the more body fluids are lost.

■ Dehydration seriously affects health

Kreno said: "If you don't replenish water in time during exercise, you will easily get tired. If you don't replenish water after exercise, your state will decline in the next few days of exercise, which will be harmful to your health in the long run. " According to the research of the National Association of Sports Injury Defenders, dehydration within one hour of exercise will damage your physical performance. If you are dehydrated from the beginning, this time will come earlier. It will also increase your risk of some symptoms of fever, such as heatstroke cramps, heatstroke failure (mild heatstroke) and heatstroke.

Jacob Teitelbaum, the author of "From Fatigue to Fantasy" (a guide to prevent chronic fatigue and fibromyalgia), said: "It is not just for athletes to replenish water in time, it applies to everyone." Replenishing water is also essential for those who are used to sedentary. He suggested: "You should pay attention to your mouth and lips at ordinary times. If they become dry, it shows that you are thirsty and need to add more water." According to the report of Gatorade Sports Science Research Institute, dehydration is a serious problem for everyone, but the danger of dehydration is more serious for children and older adults.

■ Drink water early and often during exercise

Research shows that after 3 minutes of exercise in a hot and humid environment, dehydration will occur, so you should not only replenish water during and after exercise, but also drink water before strenuous exercise. Don't wait for dehydration before drinking water, which will cause gastrointestinal pain. The American College of Sports Medicine suggests that athletes should drink enough liquid to ensure that they can replenish the water they lose during exercise, and at least 8 to 1 ounces of liquid should be replenished every minute during exercise. Don't drink water after you feel thirsty during exercise. When your body gets hot and sweaty, your thirst mechanism will shut down quickly, so you may not realize that you need to replenish fluids.

■ Make a drinking schedule

Check the color of your urine. If your urine looks like the color of apple juice, you are probably dehydrated. If it looks like the color of lemon, it means that your body is full of water.

sugary soda or fruit juice is not the best way to replenish body fluids. High-sugar drinks actually lead to dehydration, so we should avoid the practice of supplementing water by drinking drinks, including beer. If you feel that pure water has no taste, you can choose seasoned zero-calorie mineral water, which tastes like soda water but contains no sugar. Of course, there are other ways to improve the taste. For example, you can add mint or mint tea, lemon or hibiscus tea to the water. You can also drink it by pouring water into a pitcher, then adding fruit slices and freezing it until the water becomes fragrant and delicious. Il Steinbeck, the author of "Diet/Lifestyle", said that it is also a good choice to add some fruit juices (cranberry, pomegranate, blueberry juice is a good choice, because these juices have antioxidant properties) to adjust the taste of pure water.

if you really don't like the monotonous taste of water, buy a water purifier to filter out lead and other pollutants in tap water. Some purifiers can be directly installed on the faucet, while others can be used as part of the whole water supply system. You can also buy a large purifier and install it in a special pitcher, fill it with water and put it in the refrigerator.

■ Replenish water. Cold water is better than room temperature water.

Using glass (don't use plastic or paper cups) to hold water can make the temperature of water lower, keep it longer and taste fresher. If you don't like pure water, fortunately, we can also eat some high-moisture fruits in summer, such as various fruits, plums and peaches. "If you don't like drinking pure water, eat more fruits with high moisture content. You can also freeze 1% fruit juice and cut the fruits into small cubes and put them in a small ice tray, and then put them in the water you want to drink," said Intyi Sass, a spokeswoman for the American Dietetic Association. If you want to drink more water, you can gradually increase your water intake, adding one teacup at a time, so that your body can constantly adjust itself.

when people are thirsty, it means that they have lost water slightly.

don't drink plenty of water before and after meals. Drinking some sour plum soup, tomato soup, orange leaves, orange leaves and other sour soup water before meals will not only help ensure that the digestive system secretes enough digestive juice, help digestion, promote appetite, but also supplement vitamin C and prevent heatstroke. However, if you drink a lot of water before meals, it will dilute gastric juice and affect digestion. After meals, food takes up most of the space in the stomach. If you drink plenty of water, it will not only dilute the gastric juice, but also greatly reduce the sterilization ability of the human body, and increase the burden on the stomach, heart and kidneys because of drinking too much water. Therefore, after work, you should drink water before eating, and drink at most 3 ml at a time, at least intermittently for 3 minutes. In summer, the daily water supplement is about 3 ml to meet the needs of the human body. Old people are not sensitive to thirst, so they should take the initiative to drink a small amount of water many times, preferably 15 ~ 2 ml per day. However, pregnant women and breast-feeding women need more water, and the amount of water added every day should be 3 ~ 35 ml.

Drinking water needs to be supplemented with salt

After sweating in summer, some people only pay attention to drinking water to quench their thirst, but neglect to supplement salt. Because you lose a lot of water and more salt when sweating, the osmotic pressure in your body is out of balance. At this time, the water you drink can't be stored in cells, but it will be excreted with sweat, and sweating will bring out salt, forming a vicious circle of more drinking and more thirst. Severe cases can cause muscle weakness, pain and even convulsions. Therefore, in hot summer, especially after sweating a lot, you should drink some light salt water appropriately.

don't drink too much when you are thirsty

Some people are greedy for a moment and drink a lot of water when they are thirsty. These waters suddenly accumulate in the gastrointestinal tract, which not only makes the stomach feel heavy and bloated, but also affects diaphragm activity and normal breathing. A large amount of water enters the blood, which can make the blood volume increase rapidly and the burden on the heart suddenly increase, leading to abnormal cardiopulmonary function. Thirst and binge drinking can make water and salt in body fluids out of balance, which can cause severe gastrointestinal pain and endanger life safety.

Don't eat cold drinks when sweating

Eating cold drinks is also very particular. Cold drinks can clear away summer heat and quench thirst, which is worthy of being a good product for people to spend summer heat, but if they are not drunk properly, they will affect their health.

don't be greedy. Because eating too much cold drinks will dilute gastric juice and inhibit the secretion of gastric acid, which is not conducive to the digestion of food and will weaken the bactericidal ability of the stomach, thus affecting people's health.

when sweating heavily, don't drink immediately. The sudden change of cold and heat will make the human body feel difficult to adapt and easily lead to harm to the human body.

drink cold drinks carefully. Cold drinks are too cold, and drinking too much and too quickly may cause cramps in the gastrointestinal tract and cause severe pain.

some patients should not drink cold drinks. Cold drinks can shrink the capillaries of the human body, so patients with cardiovascular disease, bronchitis, pharyngitis, gastroenteritis and cholecystitis should not drink cold drinks.