Objective. To evaluate the hydration in young athletes after a 1-month intake of a specialized isotonic drink for children based on apian and herbal components F25 IsoDrink Light (IsoDrink-L).

Materials and methods. From 76 young athletes under 18 years old, of which 70 from the Ugra boarding school of the Olympic reserve of Khanty-Mansiysk (ice hockey, swimming, skiing, biathlon) and 6 highly qualified swimmers from the St. Petersburg Swimming Center Petersburg, the main group included 42 athletes with a monthly course of IsoDrink-L. The control group included 34 people who used college rehydration methods (water and regularly purchased isotonic “X”). Hydration was studied using an impedance assessment of body composition, including the calculation of the total amount of fluid (TAF), as well as intracellular and extracellular fluid (Intracell. fluid and Extracell. fluid), the Extracell. fluid/TAF ratio and a survey of participants about the method of rehydration (water or isotonic). The biochemical composition of blood, specific gravity and color of morning urine before and after a monthly course of isotonics were also evaluated.

Results. Bioimpedance measurement of the amount and ratio of body water in combination with an assessment of hematocrit, sodium, potassium, urea and lactate in the blood, as well as the specific gravity and color of morning urine made it possible to detect dehydration in all athletes before taking isotonic. The picture of dehydration in the form of cellular hyperhydration, extracellular hypohydration, hyponatremia, hypovolemia, blood “thickening and acidification” was detailed. A monthly course of isotonic demonstrated its efficiency, dehydration in athletes was eliminated. In the control group, no positive dynamics were noted, which raised the question of the inefficiency of the isotonic “X” and the harmfulness of water, which in 95 % of cases was used as a means of rehydration. The high efficiency of IsoDrink-L and the bioimpedance method was confirmed by the inverse correlation of Extracell. fluid/TAF with the level of hematocrit (r = –0.71; p < 0.0001) and lactate (r = –0.56; p < 0.0001), Extracell. fluid with the level of hematocrit (r = –0.65; p < 0.0001) and lactate (r = –0.56; p < 0.0001). The ratios of Extracell. fluid/TAF with the specific gravity of urine (r = –0.74; p < 0.0001) and its color (r = –0.65; p < 0.0001), as well as direct correlations of the Intracellular fluid with the specific gravity of urine (r = 0.79; p < 0.0001) and its color (r = 0.87; p < 0.0001).

Conclusion. Uncontrolled hydration, especially with water, does not allow maintaining a balance of sodium and fluid in young athletes, as a result of which there is intracellular hyperhydration, extracellular hypohydration, hyponatremia, polycythemic hypovolemia, worsening of blood rheology, its thickening and acidification. Up to 95 % of young athletes perform rehydration with water, not suspecting that this only enhances dehydration. Up to 5 % of highly qualified young athletes use isotonics, not knowing if they are effective. Isotonic F25 IsoDrink Light entered the FMBA Formula as a specialized isotonic drink for young athletes of the Russian national teams.

A balanced diet and intake of Specialized foodstuffs products play a key role in expanding the adaptive potential of athletes and affect the effectiveness of the training process. The review examines the current scientific evidence regarding the nutritional and energy needs of athletes to increase endurance. Comparative characteristics of various sources of protein, carbohydrates are given, the value of fats in sports practice, as well as the effectiveness of the use of combinations of various macronutrients during intense physical exertion are characterized.

The paper reviews the current data on the effect and role of varying intensity physical activity in the prevention of various respiratory virus infections, including influenza virus and SARS-CoV-2 coronavirus. The paper discusses the effect of varying intensity physical activity on antiviral immunity, cellular and cytokine responses to respiratory virus infections, physical activity influence on vaccination effectiveness and the role of regular moderate intensity physical activity in the prevention of viral infection in patients with obesity, overweight, diabetes and other metabolic disorders. The paper analyzes physical activity role in the prevention of SARS-CoV-2 infection, as well as in the conditions of self-isolation and quarantine.

Objective: to analyze the postural regulation of rugby players.

Materials and methods. 10 rugby players performed Romberg test and optokinetic test on a computer stabilograph “Trust-M Stabilo”.Amplitude and frequency characteristics, length, area of statokinesiogram, ratio of length to area; speed of center of massmovement and the work have been analyzed.The results were compared with those of healthy people not involved in sports.

Results. Athletes’ deviations and area of the statokinesiogram were greater than in the control group, though the length of the statokinesiogram was shorter. Maintaining the vertical posture required less work in athletes group. Eyes closing was accompanied by increasing the area of statokinesiogram, the speed of center of massmovement, and the frequency of oscillations in sagittal plane. Visual disturbances led to an increase in speed of center of massmovement, in length of statokinesiogram, in standard deviation and in shift of center of mass back. The effect of disturbances in athletes’ group led to fewer changes than in the control group.

Conclusions. Postural regulation of athletes proved to be better than that of healthy people who are not involved in sports. All rugby players had a similar strategy for working out disturbances.

Study objective: to establish the correlation between the paretic hand movement recovery in post-stroke patients in the stroke late residual period and the patients’ somatotypes.

Materials and methods. The study involved 91 people in the second period of adulthood (53 men, 38 women), somatotyping was performed according to the W.L. Rees — H. Eysenck method.

Results. Statistically significant differences in the upper paretic limb movement range recovery were found in men and women in accordance with the body type.

Conclusions. The highest percentage of normal movement range was recorded in the limbs’ proximal joints of the (shoulder) during movements around the frontal and sagittal axes. The volume of rotational movements as a percentage of the norm was less by 13–17%. The men demonstrated maximum movement recovery of shoulder extension, and this tendency is typical for mature men of asthenic and pyknic somatotypes. The women in all the examined groups demonstrated the minimal increase in the movement ranges in the shoulder and elbow joints.

Physical rehabilitation a promising approach in the treatment of idiopathic paroxysmal atrial fibrillation which is a important medical problem.

Study objective: To develop and scientifically substantiate reflexology and physical training methods for the treatment and prevention of regulatory functional cardiac disorders in idiopathic paroxysmal atrial fibrillation.

Materials and methods. The study involved 90 patients with idiopathic atrial fibrillation (IAF), who were divided into 2 groups: 45 patients with adrenergic (AAFF) and 45 patients with vagotonic (VAFF) forms. The patients received a complex treatment consisting of reflexology and dosed walking. The treatment efficacy evaluation involved clinical, functional and instrumental examinations, psychological tests, psychophysiological stress-test, 24h ECG monitoring to identify the standard deviation of the normal-to-normal RR intervals (SDNN); echocardiography, high-definition oscillometry, and biochemical tests.

Results. We found that the complex of reflexology and dosed walking in both groups produced an antiarrhythmic effect resulting in reliable normalization of the cardiovascular system autonomic regulation.

Conclusions. The complex normalizes the heart rate autonomic regulation and hemodynamic parameters, improves the psychological and emotional state and the quality of life. The proposed treatment demonstrated high efficiency.

The coronavirus pandemic raises an important issue of the return professional and amateur athletes to training after COVID-19 infection. Since no standard protocols for return to sports after the new coronavirus infection are approved to date, and few studies were done on SARS-CoV-2 infection short- and long-term complications in sports professionals, the question arises about the criteria for the athletes’ training restart after COVID-19 infection to protect the health of athletes and prevent long-term adverse health effects. This review is a synthesis of currently available information on the athletes’ re-involvement into the training process after COVID-19 infection.

Study objective: to establish the correlation between the paretic hand movement recovery in post-stroke patients in the stroke late residual period and the patients’ somatotypes.

Materials and methods. The study involved 91 people in the second period of adulthood (53 men, 38 women), somatotyping was performed according to the W.L. Rees — H. Eysenck method.

Results. Statistically significant differences in the upper paretic limb movement range recovery were found in men and women in accordance with the body type.

Conclusions. The highest percentage of normal movement range was recorded in the limbs’ proximal joints of the (shoulder) during movements around the frontal and sagittal axes. The volume of rotational movements as a percentage of the norm was less by 13–17%. The men demonstrated maximum movement recovery of shoulder extension, and this tendency is typical for mature men of asthenic and pyknic somatotypes. The women in all the examined groups demonstrated the minimal increase in the movement ranges in the shoulder and elbow joints.

Aim: assessment of the functional state of female students of the sports department of the university involved in track and field athletics at the pre-competition stage of the annual training cycle.

Materials and methods. The research was carried out at the Department of Physical Culture and Sports of the Yaroslavl State Medical University. It was attended by 14 students from the athletics section (experimental group) and 20 students not involved in sports sections (control group).

Conclusions. The analysis of the obtained data revealed practically equal anthropometric indicators in the experimental and control groups of the examined female students. During the mathematical processing of the results of functional tests, statistically significant differences were established between the indicators of the experimental and control groups of girl students. The Harvard Step test in the athletics group exceeded this indicator in the control group by 21 %. Also, in athletes, a significantly longer (by 23 %) breath holding time was found. A significantly shorter recovery time of the heart rate of female athletes after 20 squats was established, in comparison with untrained ones. The reaction to orthostasis among the athletes was satisfactory, and among the students from the control group it approached unsatisfactory.

Results. The results obtained indicate a high level of physical performance and recovery processes of female athletes at the pre-competition stage of the annual training cycle. The best functional state of the cardiovascular, respiratory and vegetative-vascular nervous systems of female athletes was established in comparison with the indicators of female students who do not go in for sports.

Objective: assessment of the resistance of the body of athletes-divers to the hyperbaric oxygen toxicity on indicators of the heart rate variability (HRV).

Materials and methods. The study involved 38 healthy athletes-divers aged 23 to 32 years. Before the session of hyperbaric oxygenation (HBO), the test subject was measured the blood pressure and pulse by the method of oscillometry while he was sitting at rest, after which a five-minute recording of HRV in sitting position at rest was made. After that, the two test subjects were placed together, sitting with a physician in a pressure (decompression) chamber, where an absolute pressure of 0.25 MPa was created. The test subjects were given 100 % medical oxygen to breathe, their pulse and blood pressure were measured every 15 minutes, and their cardiac output (CO) was calculated by the Starr formula. When there was an increasing tendency of the CO, and also after 75 minutes of oxygen breathing, the test subjects were taken out of the pressure chamber. Immediately after leaving the pressure chamber, the HRV of the test subjects was recorded. According to the results of measurement of hemodynamic parameters, the test subjects were divided into 3 groups. The first group — unstable, whose CO began to increase in the first 45 minutes of HBO, the second group included those whose CO began to increase from 46 to 75 minutes, the third group included test subjects whose CO did not increase.

Results. HRV analysis showed the most significant reliable (p < 0.001) VLF spectrum power (ms2) and relative VLF power (%), as well as Alpha 2 after HBO in the first group of test subjects (unstable) compared to the initial parameters and other groups, which reflects the activation of the sympathetic nervous system and suprasegmental structures of the brain. The essence of changes in the HRV time domain indicators (decrease in SNS index, pNN50 (%), PNS index) confirms the presence of pronounced sympathicotonia in the first group.

Conclusions: the three most significant metrics (VLF (ms2), VLF (%) and Alpha 2) were determined with high confidence (p < 0.001), which have a moderate negative correlation (–0.70 < r < –0.30) with the level of divers’ resistance to the to the hyperbaric oxygen toxicity. Observations of athletes with high stability showed that they were characterized by changes in hemodynamics of the vagotonic type, while unstable ones were characterized by the sympathicotonic type of regulation. Evaluation of the results showed amoderate correlation between HRV and symptom of oxygen toxicity on divers and is recommended for a reliable (p < 0.05) diagnosis.

Study objective: to analyze the activities of the regional Ryazan medical and physical dispensary in health maintaining and promoting in various medical and social groups and identify ways to improve the dispensary medical services quality.

Materials and methods: a timing study of specialists, registry and laboratory workers involved in an in-depth examination at the medical exercises dispensary in Ryazan region. The 14-day study involved 20 specialists and 50 patients who underwent an in-depth medical examination.

Results:We identifies the specialists working time consumption to develop and implement an action plan to reduce medical visit duration, the time spent by athletes at the examination stage and, accordingly, to increase the institution capacity.

Conclusions: there is an obvious need to modernize medical support for people involved in physical culture and sports in the Ryazan region due to a significant lag in the growth rates of physiotherapy and sports medicine services from the rate of new sports facilities are commissioned and a significant increase in the number of athletes involved in physical culture and sports.