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| Carbohydrates in endurance sports |
Among strength and figure sports enthusiasts and people trying to lose weight, the macronutrient that attracts the most attention is protein. However, in the case of endurance sports, carbohydrates come first and are the topic of discussion. How much to eat? From what sources? When? Are they really that important?… These are just some of the most frequently asked questions. Why did they attract the attention of endurance athletes? What are the answers to the previous questions? This and more in the text below. I invite.
About carbohydrates
They are a large and diverse group of compounds about which a lot could be written, but we want practical knowledge in an accessible form. It is worth knowing the division into simple carbohydrates (glucose, fructose, galactose) and complex carbohydrates (e.g. polysaccharides). All carbohydrates are eventually broken down in the body into the former. 80% is decomposed into glucose, but also fructose and galactose are converted into glucose after time, as a result of complicated processes. It seems that glucose is important since all roads lead to it…
Glucose is an energy substrate without which the central nervous system (brain) and red blood cells cannot function. Interestingly, we use as much as 100g of glucose per day for brain needs. The more inquisitive will argue that this is not true, because the brain can use ketone bodies produced from fatty acids. And they’re right. There is such an adaptive mechanism. However, these are not the basic conditions. It is difficult to find people who unintentionally trigger this mechanism, because carbohydrates are almost everywhere and we eat them all the time.
In the context of sports
The supply of carbohydrates may have a real impact on exercise capacity and adaptation processes. Why? First of all, the body uses carbohydrates in a wide range of training intensities, both in aerobic and anaerobic conditions – they simply always come in handy. Secondly, the amount of carbohydrates available in the body is limited and changes dynamically, depending on the supply and the efforts undertaken. If you eat fewer carbs on a given day and do a long running session, you will have trouble training the next day – the reduced pool of carbohydrates will make you tired faster. Third, scientific evidence shows that nutritional strategies that create high carbohydrate availability translate into improved performance during long-term, continuous exercise, as well as interval and high-intensity exercise – you will run faster.
Demand
Recommendations say that carbohydrates should constitute 45%-60% of the energy value of the diet. The average person should consume mainly whole grain carbohydrates. Why? They have more fiber, vitamins and minerals. This brings additional health benefits and reduces the risk of deficiencies.
Benefits of eating whole grain products:
- lower risk of type II diabetes, which is one of the most common non-communicable diseases,
- increased feeling of satiety after a meal – you will simply be more full and you will not feel like reaching for another portion,
- reduced risk of cardiovascular diseases (9% lower risk for every 7g/day of fiber),
- lower risk of constipation – this is great, because this is a problem that affects 20% of the population, which significantly reduces the quality of life and is a risk factor for colorectal cancer,
- lower risk of certain cancers – including the above-mentioned colon cancer, but also pancreas and stomach cancer,
- Increasing the amount of dietary fiber in the daily diet will contribute to improving glycemia and lipid profile (more HDL, less LDL and triglycerides).
Glycogen
Carbohydrates can be stored in our body in the form of glycogen in the liver and muscles. The liver can store 5-8% of its weight, i.e. about 100g. In turn, muscles store about 1-3% of their mass in the form of glycogen. When the sugar level in the blood or in an organ decreases, the body reaches for glycogen. Muscles are selfish and use glycogen only for their own needs.
It is believed that after 1.5 hours of continuous exercise (70% VO2max), the amount of glycogen is very low. Of course, keep in mind that it depends on your starting point. Despite the margin of error, it illustrates the situation nicely.
What if glycogen runs out?
A significant depletion of glycogen resources results in fatigue. That is why nutritional preparation for endurance competitions is so important. The idea is to maximize the amount of available carbohydrates and not allow them to run out during exercise.
Demand in endurance sports
Depending on the level of activity, the supply of carbohydrates may range from 3g/kg body weight per day to even 12g/kg body weight per day! The upper limit values are extremely difficult to cover and concern elite athletes with incredibly high physical activity.
We eat 3g/kg of body weight by accident. Some a little less, some more – it depends on what you like to eat. Values of 5g/kg body weight per day are difficult to cover by chance, let alone larger amounts. Therefore, if you are very active and want to maximize your fitness, you need to take care of yourself in terms of nutrition.
Aggressive strategies
If you run professionally, long-distance, you have probably encountered carbohydrate loading. This is a strategy aimed at preparing for the start by ensuring the highest possible availability of carbohydrates. The strategy will depend on the nature of the competition effort, but it may be as much as 10g/kg of body weight per day for 48 hours.
In the case of two training sessions in a short period of time (<8 hours break), specific nutritional strategies are also used. In this case, we should eat about 1g/kg of body weight/hour in the first 4 hours after the first training. All this so that in the second training session the availability of carbohydrates is at the highest level, and thus our performance.
Sources of carbohydrates
We mentioned above that the average Pole should choose whole grain products. Is it the same for athletes? Not completely. Remember that whole grain products provide fiber and satiety.
Athletes must sometimes, or even often, reach for simple carbohydrates to achieve the intended amounts. Of course, it’s a good idea to leave as much whole grain as possible as long as possible. Everything will depend on the person’s gastrointestinal comfort, dietary preferences and, above all, the target amount of carbohydrates in the diet.
Athletes often have a lot of sweet things in their diet – jellies, jams, juices, fruit. These are “light” products, rich in carbohydrates and tasty. Perfect for quick carbohydrate replenishment.
Recipes
Below are two examples of recipes rich in carbohydrates:
Rice with apple
Ingredients:
- rice 100g,
- 2 apples (300g),
- sugar 15g,
- cottage cheese 150g.
Preparation:
1. Cook the rice.
2. Grate the apple and boil it in a little water. Add sugar.
3. Place apples and cottage cheese on the rice.
Nutritional values:
Kcal – 674
Carbohydrates – 122g,
Fats – 6g,
Protein – 24g.
Yogurt with fruit
Ingredients:
- Natural yogurt 150g,
- Half a mango (140g),
- Banana (120g),
- Honey 25g,
- One kiwi (75g),
- Cocoa 10g.
Preparation:
1. Cut the fruit into small pieces.
2. Add cocoa, yogurt, honey and mix.
Nutritional values:
Kcal – 478,
Carbohydrates – 91g,
Fats – 6g,
Protein – 13g.
Summary
Carbohydrates, which are our main source of energy, are undoubtedly an important element in the sports puzzle. Their supply has a real impact on our sports performance. The topic of carbohydrates in endurance sports is extremely extensive and interesting. It includes daily supply, preparation for the start, nutrition during exercise, nutritional strategies for short-term training, as well as many other situations in an athlete’s life. In the short article above, I only touched on the topic, hoping to interest you. If you want to learn more or have questions while reading – please contact me.
Bibliography
The Effect of Ingesting Carbohydrate and Proteins on Athletic Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials – Lotte Lina Kloby Nielsen et al.
Skeletal Muscle Glycogen Content at Rest and During Endurance Exercise in Humans: A Meta-Analysis – Jose´ L. Areta et al.
Coingestion of Carbohydrate and Protein on Muscle Glycogen Synthesis after Exercise: A Meta-analysis – Lee M. Margolis et al.
American College of Sports Medicine Joint Position Statement: nutrition and athletic performance. Med Sci Sports Exerc. 2016 – Thomas DT et al.
Nutritional recommendations for athletes – Translated by Bartłomiej Pomorski
Nutrition standards for the Polish population – Institute of Food and Nutrition
Higher intake of fruits, vegetables or their fiber reduces the risk of type 2 diabetes: A meta-analysis – Wang PY et al.
Dietary fiber intake and risks of proximal and distal colon cancers A meta-analysis – Yu Ma et al.
Position of the Academy of Nutrition and Dietetics: Health Implications of Dietary Fiber – Wendy J Dahl et al.
Effect of dietary fiber on constipation: A meta-analysis – Yang J et al.
Human physiology – Stanisław J. Konturek
Health Benefits of Dietary Whole Grains: An Umbrella Review of Meta-analyses – McRae MP et al.