How do marathon enthusiasts use nutrition to support running health?

The 2023 Beijing Marathon will start on October 29. According to the competition regulations announced by the organizers of the event, in addition to more than 200 athletes participating in the competition, there are also approximately 30,000 public participants. In recent years, marathons have increasingly become an important platform for national fitness, displaying cities, promoting comprehensive economic development, and becoming a healthy and fashionable lifestyle for the people. Marathon is a long-term endurance sport that requires extremely high physical fitness and nutritional status of the individual. Whether the training schedule and competition period can ensure reasonable energy and nutrient intake as well as adequate hydration play a vital role in a runner’s performance and health.
So, for us ordinary mass runners, how can we use nutrition to support running health? You must know the following nutritional knowledge in advance.
How to eat during daily training period?
Fat and carbohydrates are the main sources of energy
Although there are currently few studies on the nutritional status of marathon runners in my country, the only small sample studies show that this group has problems such as insufficient total energy and carbohydrate intake and lack of nutritional knowledge.
Since the main energy supply method for marathon running is aerobic metabolism, after years of daily endurance training, increasing the maximum oxygen uptake and improving glycogen storage in the body are quite effective in improving athletic performance. Fats and carbohydrates are the main sources of energy required by the body for daily training, with only a small portion coming from protein.
Therefore, in daily training, carbohydrates need to reach 8-12G/KG/D (daily dosage per kilogram of body weight), and you can choose rice noodles, starch and potato foods. The energy supply ratio of fat should reach 20-35%. Since road running is prone to muscle loss, the protein intake needs to reach 1.4-1.8G/KG/D. You can choose lean meat, poultry, fish, eggs, soybeans and eggs. The amount of fluid supplement is 3-5L/D. You can choose boiled water or sports drinks according to the color of urine and thirst.
For example, a 60KG mass runner has a daily carbohydrate requirement of 480G-720G and a protein requirement of 84G-108G during daily training. Among common foods, 5 eggs provide about 40G of protein, one pound of fat and lean pork provides about 65G of protein, and one pound of lean pork provides about 100G of protein.
How to meet the dietary nutrition standards before competition?
Requires large intake of sugar-rich foods
Generally speaking, the body’s sugar reserves are only enough to complete 80% of the marathon distance. That is, after running for 35KM, the sugar reserves are almost exhausted. If you want to run faster and better, you need to increase your sugar reserves by consuming a large amount of sugar-rich foods before the race, such as staple foods, sugary drinks, and fruits.
Under the guidance of professionals, ordinary runners are recommended to use the gentle sugar loading method, that is, 3-4 days before the race, they continuously consume high-carbohydrate foods in small amounts and multiple times, and try to gradually reduce the amount of exercise during this period. . Starting the day before the competition, you need to replenish salt through rehydration salt or salt pills. This can not only prevent convulsions, but also facilitate water retention in the body and prevent tachycardia caused by water loss.
How to eat the right meal on game day?
Requires adequate hydration
During a marathon, you mainly consume sugar, supplemented by fat. Taking a 60KG athlete as an example, the energy required to complete a marathon is approximately 2520KCAL. Studies have shown that an elite male marathon runner consumed 474G of sugar and 27.5G of fat throughout the marathon.
Take the game starting at 7 o’clock and getting up at 5 o’clock as an example. After getting up, eat 2 slices of bread and 1 large glass of juice (add 3G of salt). After half an hour, eat an energy bar. After another half hour, drink sports drinks and mineral water. About 90% of the heat generated during long-distance running is expelled from the body in the form of heat dissipation such as sweat evaporation. The more sufficient water replenishment is, the lower the runner’s core temperature will be, which is more conducive to maintaining exercise ability. During the official competition, there will be a drinking station every 2-3KM to facilitate participants to drink small amounts multiple times.
How to replenish nutrition after competition?
Consuming high-carbohydrate foods
Marathon runners use up nearly all of their glycogen stores during a race and need to eat high-carbohydrate foods in order to restore their stores. Glycogen recovery takes 3-5 days. After the competition, you can replenish carbohydrates through sports drinks or staple foods. Replenish carbohydrates at 1.5G/KG (per kilogram of body weight) within 30 minutes, and then replenish every two hours. In addition, various trace elements are also necessary.
Female runners are prone to calcium, vitamin D, and iron deficiencies. Proper supplementation of these vitamins and minerals can help runners stay healthy, avoid injuries, and promote timely recovery after exercise.
Text/Ouyang Yifei (Associate Researcher at the Institute of Nutrition and Health, Chinese Center for Disease Control and Prevention)