Fitness is naturally good for the body, and nutritional supplement after fitness is also very important. A meal after fitness is very important for people after fitness. Proper carbohydrate intake can change the catabolic state caused by training (burning muscles to supply energy) into anabolic state (increasing muscle volume). The success or failure of nutritional supplement after fitness depends on how to ingest carbohydrates, which can promote insulin secretion after fitness. Insulin plays three important roles in muscle recovery: 1. It can "drive" the sugar in carbohydrate food into muscles and store energy for the next training. 2. Amino acids in protein food can be "driven" into muscle tissue to promote muscle growth. 3. It can inhibit the catabolism of adrenocortical hormone. Generally speaking, the intake of carbohydrates is 2-2.5g per pound of body weight for women and 2.5g-3.5g for men. In order to make full use of the opportunity of anabolism after fitness, it is best to arrange 25% of the total carbohydrates every day to be eaten immediately after fitness. It is recommended to drink milk to replenish water after fitness. Avoid indigestible protein foods such as chicken, beef and steak, and choose digestible foods such as milk, eggs and high protein. The purpose of eating at this time is to deliver enough amino acids to muscles and provide raw materials for muscle growth. Intensive training will exhaust the reserves of amino acids and glycogen in muscles. With the progress of training, the body constantly consumes the glycogen reserves of muscles. If glycogen storage is too low, it will force the body to change the energy source-use more protein as fuel. Because milk can keep moisture in the body for a long time, it is recommended to drink some milk after exercise. Dr Susan Serif, a sports physiologist, said that when people sweat, a lot of salt ions such as sodium and potassium will be lost, and milk also contains these nutrients, so sports drinks are not the only choice. Dr Susan Serif, a sports physiologist, said that when people sweat, a lot of salt ions such as sodium and potassium will be lost, and milk also contains these nutrients, so sports drinks are not the only choice. Milk can keep the body hydrated for four times as long as Gatorade, a famous sports drink. Dr Susan Serif, a sports physiologist, said that when people sweat, a lot of salt ions such as sodium and potassium will be lost, and milk also contains these nutrients, so sports drinks are not the only choice. In addition, milk also contains some sugar, protein and fat, which are metabolized slowly, so water can stay in the body for a longer time. Dr. Sharif asked a group of subjects to ride bicycles in a hot room, and then chose pure water, sports drinks and milk to replenish water. Surprisingly, it was found that the efficacy of water and sports drinks in maintaining body fluid balance was about 1 hour, while milk could maintain it for 4 hours. The results of this study were published in the latest issue of the British Journal of Nutrition.