All biological processes associated with high sports performance, including energy metabolism, are influenced by genetics. DNA sequence variations in such genes, single nucleotide variants (SNVs), could confer genetic advantages that can be exploited to achieve optimal athletic performance. Ignorance of these features can create genetic “barriers” that prevent professional athletes from pursuing a career in sports. Predictive Genomic DNA Profiling reveals single nucleotide variations (SNV) that may be associated with better suitability for endurance, strength and speed sports. (1) Background: To conduct a research on candidate genes associated with regulation of skeletal muscle energy metabolism among athletes. (2) Methods: We have searched for articles in SCOPUS, Web of Science, Google Scholar, Clinical keys, PubMed, e-LIBRARY databases for the period of 2010–2020 using keywords and keywords combinations; (4) Conclusions: Identification of genetic markers associated with the regulation of energy metabolism in skeletal muscles can help sports physicians and coaches develop personalized strategies for selecting children, teenagers and young adults for endurance, strength and speed sports (such as jogging, middle or long distance runs). However, the multifactorial aspect of sport performances, including impact of genetics, epigenetics, environment (training and etc.), is important for personalized strategies for selecting of athletes. This approach could improve sports performance and reduce the risk of sports injuries to the musculoskeletal system.

Regular physical activity in cyclic sports can influence the so-called “angiogenic switch”, which is considered as an imbalance between proangiogenic and anti-angiogenic molecules. Disruption of the synthesis of angiogenic molecules can be caused by local changes in tissues under the influence of excessive physical exertion and its consequences, such as chronic oxidative stress and associated hypoxia, metabolic acidosis, sports injuries, etc. A review of publications on signaling pathways that activate and inhibit angiogenesis in skeletal muscles, myocardium, lung, and nervous tissue under the influence of intense physical activity in cyclic sports. Materials: We searched PubMed, SCOPUS, Web of Science, Google Scholar, Clinical keys, and e-LIBRARY databases for full-text articles published from 2000 to 2020, using keywords and their combinations. Results: An important aspect of adaptation to training loads in cyclic sports is an increase in the number of capillaries in muscle fibers, which improves the metabolism of skeletal muscles and myocardium, as well as nervous and lung tissue. Recent studies have shown that myocardial endothelial cells not only respond to hemodynamic forces and paracrine signals from neighboring cells, but also take an active part in heart remodeling processes, stimulating the growth and contractility of cardiomyocytes or the production of extracellular matrix proteins in myofibroblasts. As myocardial vascularization plays a central role in the transition from adaptive heart hypertrophy to heart failure, further study of the signaling mechanisms involved in the regulation of angiogenesis in the myocardium is important in sports practice. The study of the “angiogenic switch” problem in the cerebrovascular and cardiovascular systems allows us to claim that the formation of new vessels is mediated by a complex interaction of all growth factors. Although the lungs are one of the limiting systems of the body in cyclic sports, their response to high-intensity loads and other environmental stresses is often overlooked. Airway epithelial cells are the predominant source of several growth factors throughout lung organogenesis and appear to be critical for normal alveolarization, rapid alveolar proliferation, and normal vascular development. There are many controversial questions about the role of growth factors in the physiology and pathology of the lungs. The presented review has demonstrated that when doing sports, it is necessary to give a careful consideration to the possible positive and negative effects of growth factors on muscles, myocardium, lung tissue, and brain. Primarily, the “angiogenic switch” is important in aerobic sports (long distance running). Conclusions: Angiogenesis is a physiological process of the formation of new blood capillaries, which play an important role in the functioning of skeletal muscles, myocardium, lung, and nervous tissue in athletes. Violation of the “angiogenic switch” as a balance between proangiogenic and anti-angiogenic molecules can lead to a decrease in the functional resources of the nervous, musculoskeletal, cardiovascular, and respiratory systems in athletes and, as a consequence, to a decrease in sports performance.

An elite athlete’s status is associated with a multifactorial phenotype depending on many environmental and genetic factors. Of course, the peculiarities of the structure and function of skeletal muscles are among the most important characteristics in the context of athletic performance. Purpose: To study the associations of SNV rs1815739 (C577T or R577X) allelic variants and genotypes of the ACTN3 gene with qualification and competitive distance in Caucasian athletes of the Southern Urals. Methods: A total of 126 people of European origin who lived in the Southern Urals region took part in this study. The first group included 76 cyclical sports athletes (speed skating, running disciplines in track-and-field): SD (short distances) subgroup—40 sprinters (mean 22.1 ± 2.4 y.o.); LD (long distances) subgroup—36 stayer athletes (mean 22.6 ± 2.7 y.o.). The control group consisted of 50 healthy nonathletes (mean 21.4 ± 2.7 y.o.). We used the Step One Real-Time PCR System (Applied Biosystems, USA) device for real-time polymerase chain reaction. Results: The frequency of the major allele R was significantly higher in the SD subgroup compared to the control subgroup (80% vs. 64%; p-value = 0.04). However, we did not find any significant differences in the frequency of the R allele between the athletes of the SD subgroup and the LD subgroup (80% vs. 59.7%, respectively; p-value > 0.05). The frequency of the X allele was lower in the SD subgroup compared to the LD subgroup (20% vs. 40.3%; p-value = 0.03). The frequency of homozygous genotype RR was higher in the SD subgroup compared to the control group (60.0% vs. 34%; p-value = 0.04). The R allele was associated with competitive distance in the SD group athletes compared to those of the control group (OR = 2.45 (95% CI: 1.02–5.87)). The X allele was associated with competitive distance in the LD subgroup compared to the SD subgroup (OR = 2.7 (95% CI: 1.09–6.68)). Conclusions: Multiplicative and additive inheritance models demonstrated that high athletic performance for sprinters was associated with the homozygous dominant genotype 577RR in cyclical sports athletes of Caucasian origin in the Southern Urals.

Introduction. Nowadays, the theory of sports does not contain clear criteria for assessing sports fitness, which would reflect the model characteristics of competition performance. The article presents the research results on the functional state of athletes with different training process specifics as model characteristics of competition performance. The aim of the research is to identify and describe the model characteristics of competition performance as the main criterion for evaluating sports training in the theory of sports. Materials and Methods. Energy component of athletes’ functional fitness was studied in 80 qualified athletes (Candidates for Master of Sports, Masters of Sports, International Masters of Sports), specializing in running short, medium and long distances during the period of training for competitions. The study of the energy component was conducted using the inventory developed by B. F. Vashlyaev et al. (‘A method for evaluating physical performance based on minute volume of breathing dynamics ratio to increasing load power’). This method allows to identify which source of energy is used by the athlete while taking a cycle ergometer testing. Results. The authors identified the model characteristics of functional fitness in athletes with different training specifics, based on the energy component. The study provides physiological grounding from the point of view of appropriate interaction of energy supply systems. The key regulatory mechanisms associated with the metabolic reactions activation of adenosine triphosphate molecules production are described. Conclusions. Model characteristics of athletes' competition performance, obtained in this research, can be used by coaches in order to manage sports training effectively. Moreover, the identified model characteristics can be used as the main criteria for evaluating sports training in sports theory.

Aim. The article deals with studying the functional status of the cardiovascular system and the features of its regulation in athletes of different qualifications from acyclic sports. Materials and methods. Male athletes of different qualifications aged 18–22 years and involved in acyclic sports participated in the study. A complex noninvasive bioimpedance study of HRV and hemodynamics was conducted with the Centaur (Microlux) system. The study of morphofunctional indicators of the myocardium was performed with echocardiography. Results. In athletes with the rank of Master of Sports adaptation to physical training is implemented through the increase in stroke volume, end-diastolic volume, end-systolic volume, the humoral metabolic activity of heart rate regulation, and myocardial thickening. In the athletes of the 1^st and 2^nd ranks, there is a predominance of sympathetic activity in heart rate regulation and the chronotropic mechanism in response to physical load, which proves their less perfect adaptation. Conclusion. Based on the results obtained in the transition period of training the features of myocardial hemodynamic and vegetative homeostasis were revealed. Namely, the increase in qualifications and sports performance enhancement are determined by both morphofunctional changes in the heart, and the improvement of heart rate regulation mechanisms and cardiac contractile function.

INTRODUCTION. Low-intensity resistance training with blood flow restriction is an effective strategy for increasing muscle mass and strength, as well as reducing excess subcutaneous and visceral fat deposition. In recent years, this method has been used in various populations. The purpose of this study was to evaluate the effect of low-intensity resistance training with blood flow restriction on anthropometric parameters and body composition in men with metabolic syndrome. AIM. To evaluate the effect of low-intensity strength training with blood flow restriction on anthropometric indices and body composition in men with metabolic syndrome. MATERIALS AND METHODS. The study involved 60 untrained men (mean age 38.7 ± 5.6 years) who meet the criteria for metabolic syndrome due to health reasons. Participants were divided into three groups according to resistance training regimens: low-intensity resistance with blood flow restriction; high-intensity training; low-intensity training without blood flow restriction. Before and after 12 weeks of training, the groups were assessed for body mass index, fat mass, visceral fat area, musculoskeletal mass, waist circumference. RESULTS. There was a statistically significant decrease in fat mass, visceral fat area, waist circumference and an increase in musculoskeletal mass (p 0.05) in the groups of low-intensity strength training with blood flow restriction and high-intensity strength training. In the parameters of men belonging to the group of low-intensity strength training without blood flow restriction, no statistically significant changes were found (p 0.05). CONCLUSION. In summary, the study found that low-intensity resistance training with blood flow restriction effectively altered the body composition of men with metabolic syndrome.