The higher the maximum oxygen intake, the more oxygen the body can deliver to the muscles to help burn fat and carbohydrates to generate energy. Once the speed of the race is higher than the speed of energy generation, it will hit a wall, either slow down or run. Energy production depends on who lacks oxygen or carbohydrates first (fat only accounts for 10% of aerobic metabolism, and aerobic and anaerobic systems are started at the same time in the competition, so fat metabolism is not the key factor to determine energy depletion).
Why should we share this article? Energy supplement is definitely a necessary strategy for marathon runners, especially those who emphasize race results, in which carbohydrate, the main energy source of endurance sports, is the most critical. Dr. Chen Baichang sorted out various documents, put forward energy supply strategies before, during and after long-distance running, and analyzed the physiological reasons of energy supply strategies with you from a scientific point of view. Even runners under half a horse's distance are quite worthy of reference.
Speed determines the number of steps and energy determines the running performance. The amount of oxygen or carbohydrate (liver sugar) determines the running performance. When we focus on improving Vo2max, we may ignore more oxygen, and there is not enough firewood to burn, just like Lamborghini, whose fuel tank is empty, which can't run fast and move.
For a race within 90 minutes (some people are half-horse, 5000m, 10000m), as long as the liver sugar is well prepared before the race (7- 10g carbohydrate per kilogram of body weight 24 hours before the race), it is unlikely to cause liver sugar depletion during the race, which is relatively less important for energy supplement. But for long-distance running of more than 90 minutes, such as marathon or ultramarathon, energy supplement is equally important.
Carbohydrate supplement: 75-90g per hour for long-distance running. The latest research suggests that 10- 12g carbohydrate should be supplemented per kilogram of body weight 36 hours before the competition. Early studies believed that the highest rate of carbohydrate metabolism in human body was 60g/h. However, subsequent studies found that the real limiting step was the absorption rate of small intestine, which was the most important for sodium-dependent glucose co transporter (SGLT).
High-sugar absorption training can improve the absorption rate of small intestine. The maximum can be increased to 1.75g/min, and 75-90g per hour is ideal for long-distance running performance. In a relatively short distance race, eating less or not eating carbohydrates has little effect on sports performance. At the same time, it is necessary to consider whether the energy glue or sports drinks can be completely eaten when entering the water station at a relatively high speed, and it may be necessary to slow down when entering the water station, thus affecting the competition results and rankings.
Absorption and storage of liver sugar: A healthy adult needs about 130g of carbohydrates every day during the prime time after 40 minutes of training. When doing moderate or high-intensity sports or activities, he will consume glycogen stored in the liver or muscles. The liver stores an average of 80g liver sugar, and the muscle stores an average of 500g liver sugar. The amount of storage will vary according to everyone's physical condition.
Every 1g of liver sugar will be accompanied by 3g of water storage in the body. Therefore, after several days of training, the athletes' weight dropped obviously, which means that they didn't get enough calories and water. Such insufficient calorie intake will affect the quality of training or the performance of the competition.
Liver sugar only accounts for 4% of the body's energy reserve, but muscle liver sugar and blood sugar are the first energy sources to be used during moderate and high intensity exercise (more than 60% Vo2max intensity). No matter the intensity or time of exercise, glycogen in muscle will only be used up to 90% in the end, and the body-based protection mechanism will not be completely consumed.
Glucose enters muscle cells for storage and needs the help of insulin. However, after moderate and high-intensity training, the glycogen storage in the liver is reduced, and it can directly enter the cells at high speed without the help of insulin, which is only about 30-40 minutes of prime time, which is why it is generally recommended to eat within 1 hour after training. If you miss this prime time, the rate of glucose entering the cell will decrease, but if you eat more carbohydrates, you can improve the storage rate of glycogen in muscle cells with the help of insulin, but it is still much slower than the initial 30-40 minutes.
Normal carbohydrate supplementation after training is usually not easy to cause low glycogen storage in muscle liver. When the stock of glycogen in muscle decreases, it will change the normal operation of ion pump in muscle and reduce the output of muscle strength, which may be the source of muscle pain.
Athletes in training can find obvious progress if they eat a high carbohydrate diet; However, we can't see the training effect of low-carbon hydration and diet on athletes. Neither liquid nor solid carbohydrate food will affect the synthesis of liver sugar, so as long as athletes like food (junk food-French fries will not affect the synthesis of liver sugar, but still eat high-quality food).
Eating foods with high GI after exercise can * * * insulin secretion, and at the same time increase monosaccharides in the blood, making the storage of liver sugar more efficient than foods with low GI. However, before the competition, it is obviously helpful for the existing sports table to eat high GI or low GI food. At present, it is impossible to draw a conclusion whether the pre-match replenishment is good with high GI or low GI.
After exercise, eating food with high GI can secrete insulin, and the liver sugar stock is high, which can maintain a longer race pace. In modern times, black people in East Africa dominate the world of long-distance running. There is a lot of research on Kenyan and Ethiopian athletes, from genes, climate, diet to body heat dissipation. Some of them can find differences with other races, such as genes, but they can't find obvious advantages. After comparing the body composition of East African runners and elite white athletes, a team in South Africa found that East African runners can store more liver sugar, which is considered to delay fatigue and maintain a longer race speed.
In addition to trying to increase the stock of liver sugar in the body, most of the current knowledge of * * * is to supplement easily absorbed sugar in the competition to minimize the consumption of liver sugar. In the relatively high-intensity and long-term competition, foreign sugar supplementation is not enough to support the whole competition, but it can reduce the consumption of liver sugar, so that it can be used as long as possible until the end of the competition and avoid hitting the wall.
Carbohydrate diet strategy. Eat 10- 12g/kg carbohydrate for more than 90 minutes 36 hours before the competition.
Over 90 minutes of competition, 75-90g of carbohydrates should be consumed every hour during the competition.
For competitions less than 90 minutes, you can drink a small amount of sports drinks according to the regulations of the competition.
Eat high GI food within 1 hour after exercise (ideally within 40 minutes), and cooperate with protein to help muscle tissue repair.