In order to function, the body needs fuel and building materials. Fuels provide the body with energy, while building materials allow the body to maintain and construct itself.
The main fuels are carbohydrates and fats:
Carbohydrates
Carbohydrates provide the majority of energy in the body and are also the easiest to access and utilize, providing 4 KCal of energy per gram.
Carbohydrates are typically classified into three groups:
- Monosaccharides or simple sugars: These are found in candies and fruit juices, among other sources
- Disaccharides or double sugars: These are found in regular sugars
- Polysaccharides or complex sugars: These are found in grains, rice, pasta, and starch
Carbohydrates are stored in the form of glycogen in the body, including in the muscles. Therefore, when you exercise, carbohydrates are the first to be utilized. An excess of consumed carbohydrates will be converted into body fat.
Carbohydrates consisting of mono- and disaccharides provide rapid energy release. Polysaccharides burn more slowly. Therefore, it is advisable to consume primarily polysaccharides for energy release. If you begin to feel weaker during exercise because your glycogen stores are becoming depleted, you can consume an isotonic energy drink to quickly replenish energy. These are typically the colored sports drinks.
Fats
In addition to being a source of energy, fat also serves to protect the body. Fat protects the organs and insulates the body against cold. Additionally, fat aids in the absorption of some fat-soluble vitamins. Some fats cannot be synthesized by the body and must be obtained through diet. These are the essential fatty acids. Unfortunately, fats can be stored indefinitely by the body, which can lead to various issues such as heart problems. Fat provides 9 KCal of energy per gram.
Fats are also classified into three groups:
- Triglycerides: Stored in fat cells and muscles, used when little effort is exerted
- Phospholipids
- Cholesterol
Fats are used as an energy source by the body when:
- glycogen (carbohydrates) is depleted
- low-intensity activity is performed (not during sprinting, for example)
Proteins
The primary building material of the body is protein.
Protein is synthesized in the liver and is used in the building and repair of muscles, organs, blood, and the nervous system. Protein can also be used as a fuel, but only under the following conditions:
- carbohydrate stores are depleted (for example, during dieting)
- fat stores are depleted
- high-intensity training is performed
Protein provides 4 KCal of energy per gram.
Proteins consist of amino acids – a total of 21 different ones, of which eight must be obtained through diet. These eight are called essential amino acids. The best proteins are those containing all 21 amino acids, allowing for optimal absorption by the body. It is possible to compensate for deficiencies in the diet by taking amino acid tablets, but the same results can be achieved with a balanced diet.
Protein is found in meat, fish, milk, and legumes, among other sources. If an athlete is engaged in muscle building and requires a significant amount of protein, this can be supplemented with protein drinks, also known as protein shakes. This has the advantage of providing a high amount of protein without accompanying fats. Therefore, a significant amount of protein can be consumed with a lower calorie intake.
