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Carbohydrates after exercise
Last reviewed: 23.04.2024
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Restoring glycogen stores in muscles and the liver after strenuous training sessions is of great importance for minimizing fatigue. Athletes who take 7-10 grams of carbohydrates-kg1 per day, almost completely recover the stores of muscle glycogen in the following days.
The period of time when carbohydrates are taken after physical exertion is also important for replenishing glycogen stores. Jvy et al. Estimated the replenishment of glycogen stores after 2 hours of a strengthened bicycle race, which depleted muscle glycogen.
If 2 g of carbohydrate-kg was taken immediately after the load, the synthesis of muscle glycogen was 15.4 mmol-kg 2 hours after the load. If reception of the same portion of carbohydrates was delayed for 2 hours, the synthesis of muscle glycogen was reduced by 66% - up to 5 mmol-kg 2 hours after the load. Four hours after exercise, the total synthesis of muscle glycogen after taking the delayed dose was still 45% less (13.2 mmol-kg) than with the portion absorbed immediately after the load (24.0 mmol-kg).
Liquid and solid carbohydrate products with an equal amount of carbohydrate content taken after the load, give the same rate of replenishment of glycogen stores. Reed et al. [36] studied the effect of the shape of carbohydrates on the replenishment of glycogen stores after the load. Athletes received 3 g of carbohydrate-kg in liquid or solid form after 2 hours of cycling at 60-75% V02max: half of the portion immediately after the bicycle race, the second half after 2 hours after it. Differences in the rate of accumulation of muscle glycogen between the liquid and solid forms were not observed either 2 or 4 hours after exercise.
Too long a delay in the absorption of carbohydrates after a load can reduce their accumulation and worsen the replenishment. Athletes who do not experience hunger after a load can use high-carb drinks (sports drinks, fruit juices or industrial high-carb drinks). This will also help in rehydration.
Athletes who train hard for 90 minutes every day should take 1.5 grams of carbohydrate-kg immediately after training and additionally the same portion after 2 hours. The first portion of carbohydrates can be represented by high-carbohydrate food. Replenishment of muscle glycogen stores after training is especially useful for athletes who train hard several times a day.
There are several reasons for faster replenishment of glycogen stores after a load.
- The influx of blood to the muscles is much greater immediately after the load.
- It is more likely that a muscle cell will absorb glucose.
- During this period, muscle cells are more sensitive to the influence of insulin, which contributes to the synthesis of glycogen.
- Glucose and sucrose are 2 times more effective than fructose in restoring muscle glycogen stores after a load. Most of the fructose is converted into liver glycogen, while glucose accumulates in the form of muscle glycogen.
The type of carbohydrates (liquid or solid) does not affect the replenishment of glycogen after the load. Roberts et al. Compared absorption of simple and complex carbohydrates in both depleted and non-depleted glycogen stores. The researchers determined that a significant increase in the level of muscle glycogen can be achieved with a diet rich in simple or complex carbohydrates.
The fastest increase in the amount of muscle glycogen during the first 24 hours of its recovery can be achieved by consuming foods with a high glycemic index. Burke et al. (40) investigated the effect of the glycemic index on the replenishment of muscle glycogen stores after exercise. A 2-hour bicycle race was held at 75% V02max to deplete muscle glycogen, then athletes took food with a high or low glycemic index. The total amount of carbohydrate nutrition for 24 hours at 10 g carbohydrate-kg was evenly distributed in food consumed at 0, 4, 8 and 21 h after the load. The increase in muscle glycogen content after 24 hours was greater with a diet with a high glycemic index (106 mmol-kg) than with a low glycemic index diet (71.5 mmol-kg).
- Consume 1-4 g of carbohydrate-kg for 1-4 hours before the load
- Consume 30-60 grams of carbohydrates every hour during the load
- Consume 1,5 guglevodov-kg immediately after the load with the subsequent acceptance of the same portion after 2 h
After an unusual physical load, athletes may have a worse synthesis of muscle glycogen, which will cause muscle damage. The reaction of muscles to such loads manifests itself in the deterioration of the synthesis of muscle glycogen and the reduction of its total content in muscles. While a diet that provides 8-10 grams of carbohydrates-kg, usually replenishes muscle glycogen stores for 24 hours, damaging the effect of unusual physical activity significantly delays its replenishment. Sherman also notes that even the normalization of muscle glycogen stores does not guarantee the normal functioning of muscles after an unusual physical load.