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.

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.

Chronic pain syndromes are an important medical problem generated by various molecular, genetic, and pathophysiologic mechanisms. Back pain, neuropathic pain, and posttraumatic pain are the most important pathological processes associated with chronic pain in adults. Standard approaches to the treatment of them do not solve the problem of pain chronicity. This is the reason for the search for new personalized strategies for the prevention and treatment of chronic pain. The nitric oxide (NO) system can play one of the key roles in the development of peripheral pain and its chronicity. The purpose of the study is to review publications devoted to changes in the NO system in patients with peripheral chronical pain syndromes. We have carried out a search for the articles published in e-Library, PubMed, Oxford Press, Clinical Case, Springer, Elsevier, and Google Scholar databases. The search was carried out using keywords and their combinations. The role of NO and NO synthases (NOS) isoforms in peripheral pain development and chronicity was demonstrated primarily from animal models to humans. The most studied is the neuronal NOS (nNOS). The role of inducible NOS (iNOS) and endothelial NOS (eNOS) is still under investigation. Associative genetic studies have shown that single nucleotide variants (SNVs) of NOS1, NOS2, and NOS3 genes encoding nNOS, iNOS, and eNOS may be associated with acute and chronic peripheral pain. Prospects for the use of NOS inhibitors to modulate the effect of drugs used to treat peripheral pain syndrome are discussed. Associative genetic studies of SNVs NOS1, NOS2, and NOS3 genes are important for understanding genetic predictors of peripheral pain chronicity and development of new personalized pharmacotherapy strategies.

(1) Background: The purpose of this review is to analyze domestic and foreign studies on the role of collagen-encoding genes polymorphism in the development of intervertebral discs (IVDs) degeneration in humans. (2) Methods: We have carried out a search for full-text articles published in e-Library, PubMed, Oxford Press, Clinical Case, Springer, Elsevier and Google Scholar databases. The search was carried out using keywords and their combinations. The search depth was 5 years (2016–2021). In addition, this review includes articles of historical interest. Despite an extensive search, it is possible that we might have missed some studies published in recent years. (3) Results: According to the data of genome-wide and associative genetic studies, the following candidate genes that play a role in the biology of IVDs and the genetic basis of the processes of collagen degeneration of the annulus fibrosus and nucleus pulposus of IVDs in humans are of the greatest interest to researchers: COL1A1, COL2A1, COL9A2, COL9A3, COL11A1 and COL11A2. In addition, the role of genes COL1A2, COL9A1 and others is being actively studied. (4) Conclusions: In our review, we summarized and systematized the available information on the role of genetic factors in IVD collagen fibers turnover and also focused on the functions of different types of collagen present in the IVD. Understanding the etiology of impaired collagen formation can allow doctors to prescribe pathogenetically-based treatment, achieving the most effective results.

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.

Introduction. The problem of developing clear criteria for assessing athletes’ functional fitness, which would reflect their readiness for competitions, remains under-researched in the theory of sports. Football places high demands on athletes’ functional fitness, including the vegetative component. However, attempts to improve results in football often focus on techniques and tactics to the detriment of the functional component. It should also be noted that the intensity of exercises varies depending on the playing position during matches, and, therefore, an accurate diagnostic criterion is required to assess the players’ of different positions functional readiness for competitions. The article attempts to identify the parameters of heart rate variability which could be used as markers of athletes’ playing game sports high functional performance. The aim of this research is to identify the parameters of heart rate variability as a diagnostic criterion for assessing football players’ functional readiness for competitions. Materials and Methods. In order to assess the heart rate variability, the software for the “Polyspectrum” electrocardiograph was used with an additional function of obtaining data on heart rate variability. Results. The research findings suggest that football players with high athletic performance demonstrate higher vagal and lower sympathetic modulation of the heart rhythm, which indicates their higher fitness, adaptability to loads and functional readiness for competitions. On the contrary, the athletes of the second group demonstrated signs of strain of adaptation systems and over-training. Conclusions. Monitoring heart rate variability in athletes (in particular, heart rhythm wave structure indicators, expressed as the area of the triangle formed by the spectral density of all three waves) can be used as an effective tool in the dynamic control of training, in identifying athletes’ fitness, as well as for predicting sports results.

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 1st and 2nd 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.

The purpose of the study was to develop and implement an integrated assessment of the functional fitness of athletes in the training process. Materials and methods. The study was conducted on the premises of the Olympic Sports Research Institute of the Ural State University of Physical Education. Athletes of cyclic sports aged 16-20 years (sports qualification: first rank, CMS, MS) participated in the study. For three years, we studied the parameters of the functional status of athletes at different stages of the annual training cycle. A number of studies was carried out, including an assessment of physical performance, the cardiovascular system, vegetative status, the activity of neurovegetative regulation of the cardiovascular system at rest and under exercise (active orthostatic test). Results. To clarify the contribution of the studied indicators to functional preparedness, a correlation analysis was carried out, which revealed the priority of indicators included in the integrated assessment scale. The introduction of an integrated assessment in training resulted in an increase in the number of athletes with an optimal level of functionality and an increase in sports performance. Conclusion. The presented approach to assessing functional abilities has proved its efficiency in the management of sports training.