This is what I said in an interview with a reporter before the 69kg weightlifting champion: "The others are okay, that is, it is difficult to lose weight, you can''t drink water, eat normally, you have to train, steam sauna."

　　Most athletes who participate in competitions by weight class, including boxing, judo, wrestling and weightlifting, generally participate in competitions that are 5% to 10% lower than their normal weight. That is to say, in order to make their weight meet a slightly lower weight level competition, they usually need to quickly reduce their weight before entering the competition. The most common way for athletes to quickly lose weight in a short period of time is that a few days before the competition, athletes usually reduce their weight by sweating, strictly restricting food and liquids (3 to 4 days, 3 to 4 kg) ).

　　Dehydration is the most widely used technique for rapid weight loss. Limit diet and fluid intake, perform vigorous activities in a hot environment or wear rubber clothes, or take a sauna or steam bath to cause dehydration. Infrequently used methods also include taking diuretics (belonging to banned stimulants), laxatives and vomiting drugs. Wine and coffee also have a diuretic effect. Although the effect of dehydration on the exercise of high intensity and short time (such as less than 30 seconds) is less than that of endurance exercise, there will still be some reduction in function. Moreover, repeated rapid weight loss before the game during the season will also have a negative impact on long-term health. However, as long as athletes recognize the benefits of weight loss, they will still insist on doing so, dehydration is still a major powerful means of rapid weight loss.

　　Restricted diet (high protein, very low carbohydrate) is also a method of rapid weight loss, which may reach 5-10 kg in a few weeks. Of course, like all other fast weight loss methods, when you lose weight with a high-protein, very low-carb diet, you mainly lose water, glycogen, and protein, and only a small amount of fat is lost.

　　It is worth noting that this method of weight loss (usually mistaken for weight loss) is also widely promoted by many institutions or products. Taking 0.45 kilograms (1 pound) of fat as an example, it contains 3500 kilocalories of energy, which is equivalent to the energy consumed by most athletes a day. Therefore, it is impossible to have more than a few pounds of fat in a week. Experience has shown that if weight is lost at a faster rate, this loss must come mainly from muscle and water loss, not fat. The combination of low exercise and low energy intake will result in loss of muscle tissue.

　　Dehydration, glycogen consumption, muscle loss, etc. will impair exercise ability to varying degrees (if health is not discussed for now). Therefore, in theory, the ideal way to lose weight in the game is to establish a weight goal a few months before the start of the season, and gradually reduce body fat (not more than 0.45 ~ 0.9 kg / week, that is 1 ~ 2 pounds / week) at the same time Maintain or increase lean body mass to reach the goal. Unfortunately, for many athletes, such a healthy (extended time) weight loss method is simply not feasible. Because they (kayakers) are already very lean (little body fat), they can only achieve a competition weight level by reducing a lot of lean body mass and a little fat. At this time, dehydration, reducing glycogen reserves, and sometimes including reducing protein are inevitable, these changes will obviously damage exercise capacity and performance.

　　 So, a question arises: how to restore hydration and restore glycogen storage as much as possible from the time of weighing before the game (to determine the level of the game) to the time before the actual game begins. At this time, as much as possible (without prejudice to the competition), add water, electrolytes and sugar (promote glycogen recovery)-use sports drinks (5%~10% sugar + electrolyte) plus high-sugar foods such as energy bars (at least the competition Provided in the first 2~3 hours, not within 2~3 hours before the game).