Biomedical, Legal and Technological Aspects of Nutrition for Athletes

Abstract

The relevance of the development, production and sales of specialized food products for athletes is due to the growing interest of ordinary people in sports activities and the need to adjust the diet of professional athletes. Biomedical research has established widespread violations of the optimal food structure, food and energy value of athletes’ diets and substantiated the need to develop specialized food products for athletes of various qualifications. Furthermore, the search for reliable methods and diagnostic tests that most accurately reflect the picture of metabolic changes during high-intensity physical activity is of great importance. Legal aspects of athlete nutrition, including the development of technical regulations, standards, etc., contribute to the development of this industry. The technology for the production of food products for athletes is dominated by fractionation of macronutrients of food raw materials into individual components, extraction of trace elements and minor ingredients from food raw materials, and use of modified ingredients. To develop the sports nutrition industry and optimize the nutrition of athletes, it is necessary to consolidate specialists in the field of medicine, legal regulation and production technology.

1. Introduction

The relevance of the development, production and sales of specialized food products for athletes is due to the growing interest of ordinary people in sports activities and the need to adjust the diet for professional athletes.

An integral part of such concepts as “healthy lifestyle”, “physical culture and sports” is a balanced diet, in which the metabolites consumed by the body must be replenished with high-quality food products, maintaining a balance of basic macro- and micronutrients. According to the World Health Organization, harmonizing the dilemma “nutrition-physical activity” reduces the risk of developing functional limitations by 25–50% in older age, thereby people might live on their own 10–20 years longer.

Considering the fact that the physical exertion of athletes of different specializations at various stages of the sports macrocycle and of people actively involved in sports at various periods of life differ significantly, to restore the body and maintain its adaptive potential, specialized food products with certain macro- and micronutrients composition per unit of food density are required.

Most of the information present in the Internet environment including that related to sports nutrition is in the public domain and quickly spreads among an interested audience. However, sources of information about such products on the websites of specialized stores can mislead consumers regarding the correct choice of a particular specialized food product [1]. As a result, both professional athletes and the population involved in sports activities may experience undesirable consequences after consuming specialized food products for athletes.

For example, in a survey of the target audience (n = 1267), conducted by means of an online questionnaire, while studying the consumer preferences and the provision of athletes by specialized food products, it was found that the tendency to maintain and improve the health through regular exercise stimulate the population to pay attention to specialized food products for athletes. However, as can be seen from the diagram in Figure 1, more than 55% of athletes (n = 697) made a decision to use one or another specialized food product, relying not on the opinion of specialists, but at one’s own instigation, and almost a quarter of those surveyed were guided by the advice of a coach or instructor, which competence in terms of nutrition one cannot be sure of.

Figure 1.

Distribution of answers to the question: “Whose initiative do athletes use specialized food products in their diet at?”

To prevent and eliminate contradictions in the sports nutrition industry, a competency-based approach is required with respect to medical and biological substantiation, legal regulation, and technology for the production of food products for athletes.

In general, several methodological aspects can be distinguished in the subject under consideration: biomedical, legal, and technological ones.

The unique contribution of this chapter is its assessment of multidisciplinary research in the field of sports nutrition.

The purpose of this work is to analyze the impact of biomedical research, regulatory documentation and the current state of food technology on the sports nutrition industry.

2. Biomedical aspects of nutrition for athletes

For specialists working in the field of sports biochemistry and medicine, the search for reliable methods and diagnostic tests that most accurately reflect the picture of metabolic changes during high-intensity physical activity is of great importance.

When performing any muscular activity, energy expenditure increases significantly compared to the resting state. In absolute terms, energy expenditure during regular exercise is 1050–1400 kcal per day more than in individuals with low physical activity. And for highly qualified male athletes during the training period, this difference reaches 1650–1800 kcal per day. Therefore, physical activity is one of the key parameters in the modern nutritiology.

The daily energy expenditure of an adult consists mainly of the intensity of the basal metabolic rate and the activity-related energy expenditure [2]. It is by the indicator of energy expenditure that all types of sports can be ranked depending on the intensity, duration and volume of physical activity. However, it is advisable to give recommendations on the levels of consumption of the most important macronutrients (proteins, carbohydrates and fats) not in average values, but in the form of specific indicators, that is, taking into account anthropometric characteristics, age, and gender characteristics in terms of kilogram of body weight (kgBW) of the athlete, as listed in Table 1 [3].

Sports types and main features	Examples	Energy expenditure, kcal/kg BW	Daily requirement, g/kg BW
			proteins	fats	carbohydrates
Cyclic sports (long distances)	Skiing, marathon, triathlon	45–60	1.2–1.6	1.0–1.5	7–10
Speed-strength sports (short distances)	Alpine skiing, sprinting, cycling (track)	45–55	1.4–1.7	1.0–1.2	7–9
Strength sports (maximum display of strength)	Weightlifting	40–50	1.4–1.8	0.8–1.2	5–7
Team sports (variable intensity)	Football, basketball, volleyball	40–50	1.2–1.6	0.8–1.0	7–9
Complex coordination sports (showing agility and strength)	Gymnastics, figure skating	37–45	1.2–1.4	08–1.0	6–7
Technical sports (skills in one exercise)	Ski jumping, archery	32–38	1.0–1.2	0.8–1.0	5–6

Table 1.

Classification of sports types by physical activity groups.

When an athlete’s energy expenditure is high, it is quite possible to formulate his or her diet from common food products so that it will satisfy the athlete’s needs for energy and nutrients. Athletes at risk are those who have to watch their calorie intake in some sports due to the benefits that the athletes with lighter weight have. It has been established that the prevalence of relative energy deficiency syndrome (Relative Energy Deficiency in Sport, RED-s) in athletes of various sports ranges is from 22 to 58% [4]. This can cause hormonal and metabolic dysfunctions and reduce athletic productivity.

It has been proven that in calorie-limited diets, especially those with an energy value of less than 2000 kcal, it is almost impossible to include all the necessary macro- and micronutrients.

However, both in the case of a high energy value of the diet and in the case of caloric restriction, an imbalance of essential nutrients is a common phenomenon in sports. This is confirmed by many studies dedicated to the athletes` diet.

One of the common research methods in the field of sports nutrition is the analysis of the actual diet of athletes and its correspondence to energy expenditure. Most often, two varieties of this method are used: a 24-hour nutrition reproduction method and a frequency method [5]. Using these methods, a series of studies were conducted with the participation of athletes of different specializations: basketball players, hockey players, female members of the ice hockey team, archery athletes and rowing athletes [5, 6, 7]. Based on studies of the actual nutrition of athletes, conducted by the 24-hour nutrition reproduction method and the frequency method, we detected widespread violations of the optimal food structure, nutritional and energy value of diets. The majority of the examined athletes were found to have:

• discrepancy between the daily calorie intake and actual energy expenditure;

• the share of fat and saturated fatty acids in the structure of diet calorie intake exceeds the recommended levels by 20–40%;

• total carbohydrate consumption is below the recommended level by 10–35%;

• increased consumption of added sugar (18–24%) and salt [5, 6, 7, 8].

At the same time, the majority of athletes did not analyze the nutritional value of their diet, including the amount of vitamins and minerals in it, but additionally took specialized food products and dietary supplements containing the same biologically active substances that were present in food products. The danger of this situation is that if several specialized food products and dietary supplements are taken simultaneously, a systematic overdose of biologically active substances may occur. Ultimately, not only a decrease in sports effectiveness is possible, but also health problems can appear [5].

In our opinion, regular monitoring of actual nutrition, intake of specialized food products and dietary supplements, medications, and parameters of the nutritional status of athletes is necessary to identify individual violations of the diet structure and identify interconnections as the intensity of training changes. It seems to us that the most accurate method for assessing the daily energy expenditure of athletes is the “Method for quantitative determination of personalized daily energy expenditure of a person” [9].

We believe that the insertion of specialized food products and dietary supplements into an athlete’s diet must necessarily be preceded by an assessment of the adequacy of actual nutrition to ensure that the nutritional and energy value of the diet corresponds to the level and type of physical activity. Great opportunities for collecting this data and increasing their accuracy are provided by the use of software on mobile devices with an image function [10, 11, 12]. The results of a systematic review show that storing images of foods consumed facilitates and improves self-reporting, and online nutrition counseling becomes an effective tool for monitoring nutrition. The ability to quickly receive feedback from a specialist through instant messenger chats motivates athletes to improve their eating habits [13, 14].

In addition to assessing actual nutrition before introducing specialized food products and dietary supplements into the diet, it is necessary to take into account anthropometric characteristics, age and gender differences, as well as the phase of the sports macrocycle of athletes.

The energy expenditure of athletes, the qualitative and quantitative composition of sports food and the diet as a whole are not the main indicator, but only one side of the problem of nutrition for athletes. Biochemists, physiologists, nutritionists and other specialists involved in sports technologies are also interested in the mechanisms of energy extraction during muscle activity, issues of restoration of the body, and replenishment of expended substrates after physical activity. However, the researchers themselves emphasize the lack of a unified methodology in solving this problem and the difficulties of comparing data due to differences in experimental conditions [15, 16, 17, 18, 19, 20, 21].

Researches in the field of sports biochemistry are aimed, first of all, at obtaining data on the effect of physical activity on the body, as well as at studying the response and the adaptive capabilities of athletes to organize the training process better and achieve maximum sports results. Thanks to such works it has been established that distinctive features of muscle structure appear under the influence of various training, e.g. endurance, speed, and strength development one. Figures 2 and 3 provide information about morphological and biochemical changes in muscle fibers that occur under the influence of training of various types [22].

Figure 2.

Relative muscle mass (% of body weight) during the development of different training skills.

Figure 3.

Protein content in individual structural elements of muscle fiber during the development of various training skills.

The identified structural differences in skeletal muscles, due to the nature of the functional load, were first described by Russian biochemists back in the 70s of the 20th century [16, 17]. They formulated the principle of specific adaptation of the body and its muscular system to various types of muscular activity:

• hypertrophy of physical exercise, in which the most significant changes concern protein mass;

• increase in the aerobic capacity, at which the greatest changes occur in the system of muscular respiration and oxidative phosphorylation;

• increase in the anaerobic capacity, as evidenced by the increased potential of creative kinase and glycolytic resynthesis of ATPh [23].

Modern biochemical and biophysical studies, focused on the level of molecular biology, have confirmed these data and, despite the lack of clear quantitative guidelines for the characteristics of the body response to physical activity, according to medical, biological, and biochemical studies, the main sources of energy for muscle work have been determined. It has been established that in different sports with equal energy expenditure the predominant sources of energy of working muscles are different and energy, when performing different loads, is extracted from different processes, as shown in Table 2.

Energy process	Examples of physical activity provided by energy
Creatine kinase reaction	Short-term full power exercises – sprinting, jumping, throwing, weightlifting exercises
Glycolysis	Exercises lasting from 30 to 150 s, middle-distance running, 100 and 200 m swimming, track cycling race, etc., as well as acceleration at the distance finish
Krebs cycle	Long-term low power loads
Myokinase reaction	Severe muscle fatigue

Table 2.

Sources of energy when performing muscular work.

Micromorphological and biochemical changes in muscle fibers are associated with the consumption of not only energy, but also various biologically important structures that must be restored during the rest period. Spent biological molecules are replenished mainly through food. That is why the diets of athletes of various qualifications should have a specific focus [24].

However, despite the fact that the number of publications on sports nutrition over the past two decades amounts to hundreds, the number of studies that contain reliable information about the interconnection of a particular food product with the results of physical activity is very limited. And in these studies, the same features can be seen as in the biochemistry of sports in general: the fragmentation of initial data on sports specialization, the number of participants, the experimental conditions, etc.

According to the majority of specialists in the field of sports nutrition, the “gold standard” for studying the influence of components of specialized food products and dietary supplements on competitive results is a prospective, randomized, and controlled scientific study [25]. Also, in order to form a reliable system of biomarkers reflecting the interconnection between physical activity and nutrition, a system of various well-confirmed criteria for performance, health, and recovery of the body is needed [5].

Regulatory issues are of no small importance in the development of this area of research and the sports nutrition industry in general.

3. Legal aspects of nutrition for athletes

The development of specialized food products for athletes is conjugated with the working out of standardized documents regulating terminology, raw materials composition, and other features of specialized food products for nutrition of athletes.

According to the statement adopted by the International Olympic Committee, four types of food products are classified as specialized food products for the nutrition of athletes (Table 3).

Food product category	Distinctive features
Functional food products	They are additionally enriched with macronutrients (proteins, fats, carbohydrates) or micronutrients (vitamins, minerals, etc.)
Prepared food for diet of athletes	They provide the absorption of nutrients in a more convenient form than conventional products or are convenient for use during training (drinks, gels, bars, etc.)
Selected Nutrients	Food components presented in isolated or concentrated form (protein isolates and concentrates, etc.)
Multi-component food products	They have a specific purpose due to a specific combination of nutrients (for building muscle mass, post-workout complexes, etc.)

Table 3.

Groups of food products recommended by the International Olympic Committee for nutrition of athletes [26].

In Russia and on the territory of the Eurasian Economic Union (EAEU), specialized food products for nutrition of athletes are the subject of regulation by the Technical Regulations of the Customs Union [27, 28]. According to these regulatory documents, “food products for nutrition of athletes are specialized food products of the given chemical composition, increased food value and (or) targeted effectiveness, consisting of a complex of food products or represented by their individual types, which have a specific effect on increasing adaptive capabilities of a person to physical and neuro-emotional load” [28].

Both according to the International Olympic Committee and to the wording of CU TR 027/2011 [28], food products for nutrition of athletes may contain additional biologically active components. At the same time, the level of receipt of evidence-based materials serves as the basis for determining the effectiveness of specialized food products and/or dietary supplements for athletes. Depending on the results of assessing the effectiveness of the component in the composition of specialized food products and/or dietary supplements, obtained in accordance with the requirements of evidence-based medicine, all biologically active components are divided into groups A, B, C, and D [20], as shown in Table 4.

Nutrient group	Strength of evidence	Examples of nutrients
A	The effectiveness of application for specific situations in sports is justified by methods of evidence-based medicine.	Caffeine, β-alanine, nitrates, sodium bicarbonate, glycerin, creatine, multivitamin complexes, vitamin D, iron, calcium, zinc, probiotics.
B	New scientific data were obtained that require further research with the participation of athletes. The use by individual athletes is acceptable under supervision by scientific clinical studies. Some nutrients in this group are included in it due to the experience of their traditional use.	Polyphenols, vitamin C, collagen, chondroitin sulfate, glucosamine sulfate, carnitine, fish oil, curcumin, N-acetylcysteine.
C	Scientific evidence is lacking or has not demonstrated a positive effect on athletic performance.	Branched-chain amino acids (BCAAs), leucine, tyrosine, vitamin E, α-lipoic acid, magnesium, prebiotics, phosphates, β-hydroxy-β-methyl butyrate.
D	They are prohibited or likely to contain substances which could be a reason of a positive doping test.	Stimulants (ephedrine, strychnine, sibutramine, methylhexanamine, 1,3-dimethylbutylamine and other herbal stimulants), selective androgen receptor modulators (andarine, ostarine, ligandol), metabolic modulators (GW1516 (cardarine)).

Table 4.

Groups of biologically active components, depending on the effectiveness of use in sports [26].

The meta-analysis of scientific publications presented in the Journal of the Sports Nutrition International Society [26] supported the semantic content of biologically active components of groups A and B, but as opposed to the International Olympic Committee classification, combined groups of components C and D into one category: “there is nearly no evidence of effectiveness and/or safety”. Consequently, complete unity in the terminology and the classification of specialized food products and/or dietary supplements for athletes has not yet been achieved in the international format.

In the Russian Federation, the state standard has been in force since 2018, which formulates the basic terms used in the field of sports nutrition [29]. In accordance with this document, specialized food products acquire certain characteristics and can be recommended for use for certain purposes and in specific phases of the sports macrocycle, depending on the nutrient composition: the predominance of proteins, carbohydrates or other ingredients [30]. The characteristic features of the macronutrient composition of specialized food products are shown in Table 5.

Food products	Purpose
High protein supplement	To control muscle and fat mass of the body, as well as increase speed and strength indicators
Protein-carbohydrates supplement	To increase absolute and relative indicators of the athlete’s muscle mass and restore the body’s energy resources
Carbohydrate-protein supplement	To contribute to the rapid restoration of the body’s energy resources and the increase of absolute and relative indicators of body’s muscle mass
High carbohydrate supplement	To replenish the body’s energy resources
Carbohydrate-mineral drinks	To maintain the body’s water-electrolytic balance
Isotonic drinks	To maintain fluid and mineral balance in the body
Hypotonic drinks	To replace losses of fluid and minerals in the body quickly
Dietary supplements	To activate metabolic processes, to increase adaptive potential and/or functional activity of individual organs and systems of the athlete’s body

Table 5.

Classification of specialized food products for athletes depending on macronutrient composition [29].

The same document provides concepts of the dietary features of athletes during different periods of the sports macrocycle (Table 6).

Period of the sports macrocycle	Dietary features
Preparative (basic)	Diet aimed at the perception of intense physical and psycho-emotional loads, maximizing general and special performance, reducing the impact of unfavorable factors of the training process on the functional activity of organs and systems of the body, helping to maintain muscle mass indicators at an optimal level without reducing endurance, coordination, and speed-strength qualities.
Pre-competition	Diet that contributes to bringing sports form up to the maximum level, improving the athlete’s technical capabilities, and increasing speed-strength qualities and endurance.
Competitive	Diet that allows maximizing the athlete’s capabilities, supporting and contributing to the formation of peak supercompensation, maintaining high performance, carrying out timely replenishment of the energy resources of the athlete’s body.
Restorative	Diet that replenishes the body’s energy resources and promotes the removal of metabolic products from the athlete’s body, as well as general recovery, rehabilitation and stress relief.
Before training	The use of specialized food products in the diet of athletes in addition to the basic food intake, aimed at mobilizing the body’s physical strength before physical activity.
During training	The use of specialized food products in the diet of athletes in addition to the basic food intake, aimed at maintaining physical strength during physical activity.
After training	The use of specialized food products in the diet of athletes in addition to the basic food intake, aimed at restoring the body’s physical strength after physical activity.

Table 6.

Diet of athletes depending on physiological needs [29].

All specialized food products produced and sold on the territory of the EAEU must undergo a conformity assessment procedure in the form of state registration [28]. The terms formulated in the regulatory documents regarding specialized food products for athletes impose special requirements not only on the procedure for confirming the product’s compliance with the declared properties, but also on production processes, raw materials, and technology of these products.

For specialists producing specialized food products, knowledge of current legislative information contributes to the competent selection of raw materials and functional food ingredients, and also serves as a guarantee for the production of high-quality products. Ultimately, following the requirements of regulatory documentation protects manufacturers from unwanted claims from consumers.

Athletes, when choosing a specialized food products, can derive great benefit from regulatory documents, focusing on the list of functional food ingredients allowed in them.

4. Technological aspects of nutrition for athletes

In modern technologies used in the production of sports food products there are several aspects that could be distinguished.

First of all, according to the analysis of the range of food products for athletes, it has been found out that dry mixtures prevail in all categories of these food products. Even in the sections “Drinks”, most of the products are dry concentrates. Most often, such products are presented as dry powder or granular mixtures.

The use of dry products is very convenient in sports from the standpoint of transportation, storage outside the refrigerator, creation of some supplies for the time of moving, competitions and sports training camps. However, reconstitution of dry products requires liquids that must be purchased separately and also transported, therefore, the volume of products transported by the consumer will not decrease significantly, but the cost of the finished product will ultimately increase.

To reconstitute dry products, most manufacturers recommend using not only water, but also juices and skim milk, which have their own set of macronutrients, this, accordingly, affects the food and energy value of the product reconstituted from a dry mixture. It is usually not taken into account by the consumer. For example, Figure 4 shows how the nutrient ratio in a serving of a protein mixture for sports nutrition changes when dissolved it in water, skim milk or juice.

Figure 4.

Change in food value of dry mixture for diet of athletes with different methods of preparation.

The diagram shows that when the protein mixture is dissolved in both milk and juice, the carbohydrate content increases several times, but athletes may not pay attention to this, or make a mistake in recalculating the nutritional value of the finished product.

The study of specialized food products for athletes, presented in retail chains, regarding the raw materials used confirms that all raw materials components of the food products have been subjected to processing with varying degrees of technological impact before being combined into the mixture (Figure 5).

Figure 5.

The most important directions in SPP technology for athletes.

The most common technological technique is the fractionation of macronutrients of food raw materials into separate components: protein, lipid, and carbohydrate ones, which are ultimately aimed at developing food products with a similar profile. In this case, the degree of fractionation varies according to the depth of separation: extraction of whole macronutrients or separation of constituents. For example, among specialized food products of protein and carbohydrate profiles, there are mixtures that contain skim milk, milk protein concentrates, plant-based proteins, various types of vegetable oils, starch, and dietary fiber of various origins.

Upon deeper processing of macronutrients, their further fractionation is achieved, for example, separating whey proteins from casein, polysaccharides from mono- and disaccharides or extracting lecithin from soy or eggs, etc. with the use of high-tech innovative technologies. In particular, when processing dairy raw materials, membrane separation methods such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis are widely used.

Modern technologies make it possible to extract micronutrients and minor ingredients from food raw materials. For example, to preserve the native properties of biologically active components of dairy raw materials, such as enzymes, immunoglobulins, peptides, etc., fine physicochemical and biochemical separation methods are used, which include chromatography, gel filtration and other methods. Despite the innovativeness and progressiveness of such developments, their industrial application is still poorly scaled due to imperfections in technology, low efficiency of processes, and high cost of finished products. Consequently, in most multicomponent mixtures for athletes, which are prepared from dry ingredients, vitamins, mineral elements, redox enzymes, immunoglobulins, peptides and other biologically active substances are included in the mixtures as added ingredients, what increases the cost of the finished product significantly.

A common technique in specialized food products technology for athletes is the use of modified ingredients. In particular, biopolymer hydrolysis technologies are common for further processing of extracted macronutrients. Hydrolytic processing methods are used for proteins, carbohydrates and lipids, both of animal and plant origin. Another option for modification of proteins, especially plant proteins, is texturing of different types. Also among specialized food products for athletes there are examples in which the lipid component is subjected to interesterification or hydrogenation.

According to the market review, dry concentrates of milk protein and their modified forms are very popular in sports food products. For example, in protein complexes the total share of milk proteins reaches 75–90% of the total mass of the product. In a series of specialized food products for nutrition of athletes, developed at the Federal State Budgetary Institution of Science the Federal Research Center for Nutrition and Biotechnology, dry concentrates and isolates of milk proteins and whey proteins are used.

The predominant ingredient in powder mixtures across all sports food product categories is simply whey powder or skim milk powder. These types of dairy raw materials have a pleasant neutral taste, a color from white to cream-light and can be successfully combined with both sweet and spicy ingredients. Both powdered milk and dry milk processing products are high-quality products with high food and biological value, what determines their inclusion in the composition of specialized food products for athletes.

Most food products for athletes include ingredients of other origins in addition to whey powder or skim milk powder, such as egg whites, soy, collagen from various sources and other food ingredients.

Figure 6 shows the proportion of specialized food products for athletes which contain certain types of milk proteins.

Figure 6.

Equity proportion of specialized food products for athletes containing various milk proteins, %.

The enumerated ingredients of raw milk perform several functions simultaneously in the specialized food products for athletes. Firstly, powdered milk raw materials increase the total dry matter content in food products significantly and provide high food value. Secondly, it improves the biological value due to the unique combination of essential amino acids remarkably. Finally, milk proteins have a whole range of technologically important properties: they are surfactants, can cause gel formation of food systems and stabilization of emulsions, provide emulsification and foaming during whipping.

According to the analysis of the composition of more than 100 types of specialized food products for athletes, the predominant technological solution by the production of such food products is the formation of multicomponent mixtures.

To form a certain direction in the specialized food products, the necessary functional nutrition ingredients are usually introduced into the initial raw materials.

The analysis of the composition of specialized food products produced for athletes showed that almost every second such food product contains vitamin and mineral supplements or dietary fibers, or the two of them at the same time. An idea of the number of specialized food products for athletes enriched with various functional nutrition ingredients is given in Figure 7.

Figure 7.

Equity proportion of specialized food products for athletes with the corresponding functional nutrition ingredients, %.

The functional properties of dietary fibers come to the fact that they stimulate the growth of normal microflora of the large intestine and affect the processes of absorption, microbiocinosis and evacuation of food significantly, that is, they exhibit the typical prebiotic properties. However, as indicated in the International Olympic Committee materials (Table 4), no data have been obtained confirming the positive effects of prebiotics on sports performance [26].

On the contrary, there are far fewer examples of probiotic food for athletes, although convincing scientific evidence has been obtained for probiotics on the effectiveness of their use in specific sports situations [26].

Among the functional nutrition ingredients for which a positive correlation with increased physical activity has been confirmed, caffeine and creatine are allowed in the Russian Federation. Caffeine has been proven to be effective for both long-term endurance exercise and short-term intense exercise. As can be seen in Figure 6, caffeine is present in 5% of the specialized food products.

One of the popular supplements positioning food products for athletes as food products for restoring, fat burning, weight loss, and as energy products is carnitine. Carnitine is also included in dry mixtures, gels, drinks, and bars, although proof of the effectiveness of this ingredient in specialized food products requires further research with the participation of athletes.

5. Conclusion

To optimize the nutrition of athletes, the consolidation of specialists in the field of medicine, legal regulation and production technology is necessary. Creating a methodology for commodity evaluation and classification of sports nutrition products with increased adaptive efficiency and the ability to regulate the intended purpose is an urgent task in the technology and merchandising of such products.

For biomedical specialists, the creation of a system of biomarkers that reflect the interconnection of nutrition with the criteria of productivity, health and recovery of the body remains relevant. Based on these studies, it is necessary to develop individual recommendations for adjusting the diets of individual athletes or groups of athletes. As a bank of such data is formed in the near future, personalization of the diet in accordance with the individual metabolic and genetic profile of the athlete is quite possible.

To fill personalized diets, it is necessary to develop individual technologies for sports nutrition products. When creating SPP, not only the scientific justification for the choice of biologically active substances, but also the principle of “do no harm” is relevant. The introduction of PPI with proven effectiveness should not exceed physiologically active quantities and worsen the consumer and functional-technological properties of the SPP.

When developing a specialized food product, not only the scientific justification for the choice of biologically active substances, but also the principle of “Do no harm!” is relevant. The introduction of functional nutrition ingredients with proven effectiveness should not exceed physiologically active quantities and worsen the consumer and functional-technological properties of the specialized food products.

All specialized food product and/or dietary supplements must be purchased only if there is information and state registration of these products in the Unified Register of the EAEU, in order to eliminate the risk of the product containing substances included in the World Anti-Doping Agency Prohibited List.

Acknowledgments

The research was conducted with the financial support of the Ministry of Science and Higher Edu-cation of the Russian Federation (research project No. FGMF-2022-0004).

Conflict of interest

The authors declare no conflict of interest.