There are tips for challenging a marathon: experts teach you how to eat before, during and after

Let’s first look at the real situation of runners the day before a weekend full marathon: they practice long-distance running regularly on weekdays. The day before the race, runners make pre-race preparations to welcome the race. They get up at 5:00 in the morning to have breakfast, do some light running training, and go to bed at 8:00 in the evening to get enough rest for the next day’s race. On the day of the competition, I chose to go on an empty stomach because I was afraid that I would feel uncomfortable during the competition after eating breakfast. In the first 2 kilometers of the marathon, the situation was the same as usual; at 4 kilometers he began to feel muscle fatigue; at around 8 kilometers he began to feel that he was unable to go on; at 12 kilometers he decided to end the day's race early.

This case tells us the importance of diet when we compete. If we want to get outstanding results, we cannot rely solely on continuous pre-race training. I often receive questions from runners: What to eat? When to eat? It is closely related to performance during the game. Are you eating right? Paopao invited Associate Professor Chen Yuyong from the Department of Physical Education at the National Taiwan University of Sport and Physical Education, who is also a national civil servant nutritionist, to provide professional dietary advice to runners.

Various sports science studies have confirmed that the energy consumption of any exercise is closely related to the intensity and duration of exercise. If you want to know how to replenish before exercise, you must first start by understanding how our body consumes energy when we exercise. Any activity requires energy. The energy provider is the ATP system, which releases and decomposes the energy into calories. Physical activities do work according to calories and generate energy. How much energy do we consume when running a marathon? According to research, an average of 60 calories are consumed per kilometer. During a marathon, energy consumption is determined by the running speed. The faster you run, the more you rely on carbohydrates (glycogenotype, glucose). The slower you run, the more you rely on fat.

In a marathon, the longer the exercise time and distance, the lower the exercise intensity and the less intense the exercise. However, at the beginning of the competition, the body will first consume the body's glycogen. When the body's glycogen is exhausted, the body will begin to experience symptoms such as fatigue and muscle weakness, which will affect the competition condition and results. Therefore, the current marathon diet uses the glycogen overload method, which is the most effective diet method that has been proven to be most consistent with exercise physiology.

What is Glycogen Supersupplementation?

The main food fuels for exercise are carbohydrates and fats. However, for endurance exercise lasting several hours or longer, fat is even more important. Muscle fatigue occurs immediately after muscle glycogenolysis is depleted, so it is important to maintain adequate muscle glycogenolysis stores at all times. Glycogen supersupplementation is usually combined with exercise to increase muscle glycogen storage. Many experiments have confirmed that muscle glycogen storage has a very positive relationship with endurance performance. When marathon runners run a marathon, they mainly rely on glycogen for energy in the first 30 minutes. Glycogen exists in the muscles and liver, and the body's energy is consumed in the following order: glycogen in the muscles → glucose in the blood → glycogen in the liver → neutral fat in the blood.

When the glycogen in the muscles is consumed, the body begins to hit the wall. In order to have a perfect performance in the competition, Associate Professor Chen Yuyong recommends that carbohydrate intake is very necessary. It takes about 30 minutes for carbohydrates to be absorbed and effectively utilized by the human body after being ingested. Studies in recent years have found that no matter when carbohydrates are supplemented before a game, it is beneficial to athletic performance. These studies show that consuming carbohydrates 30 minutes, 45 minutes, 1 hour or even 2 hours before a race does not negatively affect aerobic exercise and may even improve athletic performance. Replenishing sugar 30-45 minutes before exercise is the best time to maximize blood sugar levels.

What should you eat before, during, and after a game?

Preparation period: The week before the marathon begins the preparation period. Associate Professor Chen recommends a high-carbohydrate diet to increase sugar reserves to provide enough energy to cope with the competition. The daily diet should contain 55% to 60% carbohydrates. It is recommended to consume 9 to 10 grams of carbohydrates for every kilogram of body weight to increase the storage of glycogen. During normal training, low-GI foods should be consumed as the main food. If intensive training is performed, high-GI foods should be supplemented. In a British study, both men and women who added 1 gram of carbohydrates per kilogram of body weight the day before a race increased their speed by 0.1 miles (0.16 kilometers) per hour during the race.

Before the game: 2 to 4 hours before the game, try to eat as much food as possible, mainly carbohydrates, so that the body can store enough glycogen, and try to consume less protein or high-fat foods to avoid discomfort caused by incomplete digestion of food during the game. One hour before the game, you should drink 600 ml of water and take in 30 to 50 grams of carbohydrates. People who sweat a lot can also supplement with some sodium.

Post-race: Within 15 to 30 minutes after the race, take a recovery snack consisting of 50 grams of carbohydrates and 12 to 15 grams of protein. At the same time, in order to prevent dehydration, you should replenish water or sports drinks immediately after the game. Comparing the weight before and after the game, you need to drink 480 ml of water for every 0.5 kg of body weight loss. It is very important to supplement high carbohydrates after exercise, especially within 2 hours after exercise. Studies have found that eating carbohydrates immediately after exercise (1.5 grams per kilogram of body weight) and repeating the same amount two hours later can quickly restore the body's glycogen stores, accelerate muscle recovery, and reduce the occurrence of fatigue.

What are high-carb foods?

Carbohydrates are so important for endurance athletes, so what foods are rich in carbohydrates? Carbohydrates are the most important nutrients for supplying energy to the body, and are generally divided into monosaccharides, disaccharides, and polysaccharides. After digestion, carbohydrates are more easily absorbed and utilized by the body as glucose and fructose. Carbohydrates, also known as sugars, include glucose, starch, sucrose, and cellulose.

A few days before the competition, you can increase the carbohydrate ratio in your diet to increase the glycogen storage in the body. Pasta, rice, bread, corn and various fruits are all good sources. Try to choose natural, unprocessed foods, which have more vitamins, minerals, and dietary fiber, allowing you to reserve full energy before the competition without causing the trouble of excessive carbohydrate storage and fat accumulation.

Carbohydrates during competitions should be mainly glucose, as fructose alone may cause gastrointestinal discomfort. Sports drinks or sports gels are good choices. In addition to electrolytes (sodium, potassium, and chloride), sports drinks also contain about 5% to 10% carbohydrates to replenish energy. The purpose of carbohydrate replenishment is to maintain the intensity of exercise. Drinking about 30 to 60 grams of carbohydrate drinks per hour can effectively maintain blood sugar and thus maintain athletic performance. Athletes can drink 0.5 to 1 liter per hour to achieve the goal of replenishing 30 to 60 grams of carbohydrates per hour. However, the carbohydrates in sports drinks should not be too much. If the concentration exceeds 8%, they will easily remain in the stomach and hinder the absorption of water.

What to eat after a game? Supplementing carbohydrates can maintain blood sugar and glycogen consumed by muscles; while protein helps muscle protein synthesis, repairs muscle tissue damaged by exercise, and even increases the basal metabolic rate and accelerates fat consumption.

Good choices include whole grains, root vegetables, and fruits, especially high-fiber fruits and vegetables such as oranges, apples, kiwis, tomatoes, etc., which can also be made into juice for drinking, which can not only replenish the vitamins and minerals lost after exercise, but also reduce hunger after exercise. You can supplement carbohydrates and protein foods in moderation within 30 minutes to 1 hour after exercise. The calorie intake after exercise is about 300 calories. For example, drinking a cup of soy milk with a sweet potato can replenish the nutrients needed after exercise.

What sports supplements can I take before and after exercise?

During competition, the body will sweat a lot, and electrolytes in the body will be discharged. If not properly replenished, electrolyte imbalance may occur. If the exercise lasts for more than an hour, it is recommended to use sports drinks. In addition to replenishing water, it also replenishes sodium, potassium, a small amount of calcium and magnesium, which are the energy needed for exercise. Energy bars and energy gels are also a good choice during exercise, as they can quickly relieve hunger and replenish sugar during the game.

Energy bars are mainly solid and can be divided into three basic types:

1. High carbohydrates, low protein, and low fat: The carbohydrate ratio is about 90-50%, which is suitable for endurance sports competitions.

2. Balanced carbohydrate, protein and fat formula: 40% of calories come from carbohydrates, 30% from fat and 30% from protein. It can be used as a snack between training sessions and for daily use by athletes.

3. High protein formula: mainly for fitness enthusiasts.

Energy gel is a gel-like supplement that combines the advantages of "liquid" sports drinks and "solid" energy bars, making sports supplements absorbed faster and easier to digest. Energy gel provides more energy than sports drinks and is easier to digest and absorb than energy bars. Therefore, it is suitable for high-intensity training, competition or situations where quick energy replenishment is needed. However, the calories and hunger-relieving effect provided by a serving of energy gel cannot be compared with that of an energy bar.

Many foreign studies have also confirmed that low-fat chocolate milk is a very good sports supplement after exercise. Dr. William Luen, a sports scientist at the University of Connecticut, said that the carbohydrates and protein in chocolate milk can increase glycogen concentration and muscle energy, which can replenish energy for tired muscles. The subjects of the study were 8 male runners, who consumed a balanced diet during the 2 weeks of the study to maintain their physical fitness. At the end of each week, they would run briskly for 45 minutes.

After their run, some people drank 16 ounces of nonfat chocolate milk, while others drank 16 ounces of a sports drink. Muscle biopsies taken after exercise found that those who drank chocolate milk had a greater increase in skeletal muscle protein synthesis than those who drank the sports drink, indicating that their muscle rebuilding ability was greater. A study conducted by the University of Texas at Austin and published in the American journal Strength and Conditioning Research showed that consuming a moderate amount of low-fat chocolate milk after exercise can help enhance muscle endurance and burn fat to a considerable extent, and can also improve exercise results.

There are all kinds of sports supplements on the market. Associate Professor Chen said that as long as you eat right and follow the principle of glycogen super-replenishment to choose food and supplements, it will be of better help to the body's needs and athletic performance. Before you start running tomorrow, don’t forget to start adjusting your diet based on the advice in this article and observe the changes and performance of your body!

Associate Professor Chen Yuyong, Department of Physical Education and Institute of Physical Education, National Taiwan Sport University

• Education: PhD in Food Science and Technology, National Taiwan University

• experience:

Taoyuan Zhensheng Hospital Clinical Nutritionist

National Examination for Public Nutritionist

Assistant Professor, Department of Medical Nutrition, I-Shou University

Associate Professor, Department of Physical Education, National Taiwan Sport University

• Related certificates:

National Higher Examination Professional Nutritionist Examination

National Higher Examination Professional Food Technician Examination

National General Examination Hygiene and Environmental Protection Food Management

Patent Attorney in the Republic of China

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