Water is the most important element among the "six nutrients" to keep us alive; The total body fluid of adults accounts for about 60% of body weight, and body fluid is composed of water, electrolytes, low molecular compounds and proteins, which are widely distributed inside and outside the cell and constitute the human body environment.

For outdoor mountaineering hikers or sports, whether the body moisture is sufficient directly affects their sports performance, and even affects the safety of the body in serious cases. Although it was mentioned in Food for Climbing in Hong Kong that there are very few cases of malnutrition due to insufficient food during climbing activities in Hong Kong, the cases of fatigue and even heat stroke due to lack of hydration occur from time to time every year. On average, 2-4 litres of water is lost per day during normal hiking activities; On the other hand, prolonged climbing in hot weather increases the amount of water lost by 5-7 litres per day. The saying "drink less water when hiking" is a thing of the past. The serious health consequences of the loss of water from the body are medically recognized.

Dehydration (water loss as a percentage of body weight) has the following consequences:

More than 2% -- a change in body temperature. Greater than 3% - Decreased muscle endurance. Greater than 4% to 5% - Decreased strength and endurance. Greater than 6% - cramps, strokes, coma due to inability to dissipate heat. More than 11% - the onset of serious renal dysfunction and even death.

If you lose 3% of your body weight in water (i.e., 1.63 liters of your body weight in the case of 120 pounds), your blood concentration increases and your heart starts to stress. Losing 4-5% is hard to concentrate; Affects marching and deformations during walking, causing an increase in accidental falls. Losing more than 6% May result in accidental death.

Requirements for drinking water in field activities:

1. supplement as early as possible, don't wait until you feel dry mouth to drink water

2. to a small number of times as the principle, 15-25 minutes each time recommended 100-150 ml

3. In the process of hiking, the consumption and intake of water are basically balanced

4. the appropriate supplement of sports drinks, can quickly let the body absorb the right amount of energy and electrolytes if in the hot summer to participate in outdoor activities, if the activities need to bring water and sports drinks are frozen into ice to carry, so in a hot environment under the high temperature activity. There will be cool, cold drinks to supplement the journey, which will be a great pleasure. In addition, in hot summer, ice drinks can make you feel comfortable, which can indirectly help regulate body temperature to return to normal state, prevent and avoid the occurrence of heat injury such as heat stroke caused by outdoor activities in high temperature and bad weather.

Supplement 500 ML liquid 2 hours before exercise, can increase the body muscle glycogen, liver glycogen reserve. Replacing lost fluids after exetcise can accelerate the recovery of lost water, sugar, inorganic salts and trace elements in the body, promote the rapid recovery of muscle glycogen, and achieve the role of eliminating fatigue. The method is to replace 1000 ml of fluid for every 1000 g of body weight lost. The choice of sports drink in fitness exercise can quickly replace the liquid, energy and electrolytes lost due to sweat, which can effectively maintain or even further improve the state of the human body during or after exercise.