Proteins are organic compounds formed by long chains of amino acids. They basically fulfill structural and regulatory functions, although in some cases the organism can use them to obtain energy. Nutritionally the proteins that we ingest interest us to satisfy our demands of amino acids, which we will use to synthesize new proteins, nitrogenous bases, hormones, neurotransmitters…
Importance of proteins in physical exercise
Proteins are relevant to exercise for the following reasons:
Physical exercise increases protein demands because of increased degradation during exercise and increased biosynthesis during recovery.
They are necessary for the replacement of muscle proteins damaged during exercise.
In the final phase of some high-intensity and long-lasting exercises, amino acids can be used as an important source of energy (the energy share of proteins during physical exercise can be 4% of caloric expenditure if there are good glycogen reserves and up to 10% of caloric expenditure if glycogen reserves are deficient).
There are certain situations in which it is of vital importance to ensure a correct protein intake:
- Very intense strength training
- After very strenuous efforts
- Sports in which it is difficult to eat normally
- Strict vegetarians
- Hypocaloric regimes
- Special age groups: teenagers, older people…
A protein deficit could result:
- Decreased muscle mass
- Increased risk of injury
- Increased risk of chronic fatigue
Protein quality and dietary protein sources
Proteins do not always show the same ability to meet the needs of the body. According to this, the concept of protein quality has been established, since the organism needs, at a certain moment, a number of amino acids and in a certain proportion to attend to the synthesis of specific proteins of the human body. Therefore, the protein that is taken with food will be of greater or lesser quality, depending on whether it provides to a greater or lesser degree the amino acids that the body demands. In other words, the quality of a protein represents the degree of chemical approximation of the protein of the diet with respect to that of the body.
We are now going to see which are the best protein sources of the diet taking into account their quality:
Food of animal origin
Eggs, meat, fish and milk. They contain large amounts of protein and are also of the highest quality of all foods.
Cereals, legumes, and nuts. They contain very remarkable quantities of proteins, but in this case, they are of lower quality than those of animal origin.
Foods of vegetable origin
Fruits, vegetables and vegetables. They are foods with minimum protein content and poor quality.
Proteins and dance
Dance is a high-performance physical activity. Classes, rehearsals, shows, working hours,… demand from the dancer an optimal state of health. The dancer is an athlete, and as such, his body must have the energy necessary to carry out his activity.
Proteins repair breaks in muscle fibers. Protein sources also act as an auxiliary fuel and are important for the synthesis of enzymes necessary for metabolism. The recommended daily amount would be between
1.4 – 1.6g Protein / kg.
Position Statement of the International Sports Nutrition Society
Due to the existing controversy about the safety and effectiveness of protein intake that is currently recommended in athletes, the International Society for Sports Nutrition published a position statement. Seven basic conclusions are drawn from this document:
- A considerable number of studies support the idea that individuals involved in regular training require more protein in the diet than sedentary individuals.
- Protein intakes of 1.4-2.0 g/kg weight/day for active individuals are not only safe but may improve exercise-induced adaptations to training.
- When part of a nutrient-dense, balanced diet, protein intake at this level is not detrimental to kidney function or bone metabolism in healthy, active people.
- While it is possible for physically active individuals to obtain their protein requirements from a regular and varied diet, protein supplementation in different forms is a practical way for athletes to ensure adequate and quality protein intake.
- The different types and qualities of proteins can affect the adaptability of amino acids after protein supplementation. The superiority of one type of protein over others, in terms of optimization of recovery and/or adaptations to training, has yet to be convincingly demonstrated.
- Protein intake at the appropriate time is an important component of a general training program, it is essential for proper recovery, immune function and the growth and maintenance of lean body mass.
- Under certain circumstances, supplements with specific amino acids, such as branched-chain amino acids (BCAAs) can improve exercise performance and post-exercise recovery.