The aim of the study: to developed the algorithm for the examination of the young athletes with prolongation of the QT interval on a standard ECG.

Materials and methods: based on the analysis of literature and our own experience, an algorithm for examining athletes with a prolongation of the QT interval on an ECG has been developed.

Results. The algorithm of examination includes sequential examination and sport admission of the athletes with prolongation of QT interval (QTc on an ECG more than 460 ms) in order to differentiate diagnosis of its prolongation.

Conclusion. The proposed algorithm for examining athletes with QT prolongation on an ECG can be used for the differential diagnosis of long QT syndrome and secondary prolongation caused by overtraining. Its use will optimize the cost of the examination and avoid unjustified expensive examinations in athletes with secondary or stress-induced prolongation of the QT interval.

Objective. To evaluate the accuracy of blood lactate concentration measurements using three portable analyzers compared to a stationary reference instrument.

Materials and methods. Capillary blood samples were collected from highly qualified athletes during staged comprehensive examinations under laboratory conditions. Blood lactate concentrations at rest and following incremental exercise tests on a ski ergometer, cycle ergometer or treadmill were determined using three portable lactate analyzers (Lactate Plus, YST and Eaglenos) and a semi-automatic photometric analyzer (BTS-350).

Results. The limits of agreement for lactate measurements by the Lactate Plus, YST and Eaglenos analyzers compared to the reference instrument exceeded the acceptable interval set at ±2.1 mmol/L. All portable lactometers systematically underestimated lactate concentrations by 2.0–4.0 mmol/L relative to the reference analyzer, which critically distorts the assessment of exercise intensity. Standard errors of estimate of lactate concentration measurements across the entire range were 0.95, 0.63 and 0.91 mmol/L for Lactate Plus, YST and Eaglenos, respectively, and increased with rising blood lactate concentration.

Conclusion. The portable lactometers examined cannot be recommended for accurate blood lactate measurement in athletes under field or laboratory conditions.

Purpose. The study was aimed to compare the physique, physical fitness, and kinematics of the V1 skating technique of high-level biathlete with different average distance speeds during the competitive season.

Methods. The study involved 53 elite biathletes. Their physique and physical fitness indicators were assessed at the end of the preparatory period. The parameters of the V1 skating technique were recorded during competitions and normalized to a standard speed of 5.89 m/s. The average distance speed over the season was estimated using the regression residual from the relationship between the average race ranking and shooting accuracy.

Results. Athletes with a higher seasonal distance speed demonstrated: a shorter free glide duration and a lower ratio of glide time to push-off duration, as well as a larger knee angle at pole plant and a bigger amplitude of vertical displacement of the body’s center of mass. This group also had higher body weight and muscle mass, lower maximum anaerobic power of the leg muscles, and a tendency towards better strength and aerobic capacity during upper-body work. After matching the groups for body weight and muscle mass, all statistical differences in skating kinematics disappeared. However, in the sample of faster biathletes (with the same weight), better anaerobic threshold was recorded.

Conclusion. Biathletes with a better distance speed in competitions were characterized by lower “push-off activity” and lower horizontal speed loss per cycle, coupled with bigger vertical oscillations of the center of mass. The differences in kinematics appear to be largely determined by the difference in body and muscle mass.

Objective: to investigate the association between the I/D polymorphism of the ACE gene and hemoglobin oxygenation and its affinity for oxygen, as well as to assess the contribution of individual components of the oxygen transport system in young men depending on physical activity and the ACE gene polymorphism.

Materials and methods: The study involved 201 young men aged 21 ± 2 years. Depending on their level of physical activity (PA), the subjects were divided into two groups. The first group consisted of student-athletes engaged in track and field (middle- and long-distance running) (n = 50). The second group comprised students with low PA (n = 151). General blood parameters were determined: total red blood cell count (RBC), hemoglobin concentration (HGB), mean corpuscular volume (MCV), hematocrit (HTC), and mean corpuscular hemoglobin concentration (MCHC). Additionally, oxygen tension at 50 % blood desaturation (p50), partial pressure of oxygen and carbon dioxide (pO₂ and pCO₂), concentrations of oxyhemoglobin and deoxyhemoglobin (HbO₂, HHb), and pH were measured. Hemodynamic parameters were assessed. DNA was extracted from blood lymphocytes using a sorbent-based method. Genotyping of samples was performed using real-time PCR.

Results. Factor analysis revealed that the presence of the D allele of the ACE genotype determines an association between decreased PA levels and impaired oxygen saturation parameters, which increases the likelihood of adverse changes in the functional state of the cardiovascular system. In carriers of the I/I genotype, a decrease in PA level is associated with a reduction in the total respiratory surface of red blood cells without placing strain on the circulatory system.

Conclusion. Differences in hemoglobin affinity for oxygen are genetically determined. In carriers of the D allele, hemoglobin oxygenation depends on the level of PA. In individuals with the I/I genotype of the ACE gene, a decrease in hemoglobin’s affinity for oxygen, regardless of the intensity of muscular activity, ensures the body’s ability to maintain the necessary level of oxygen delivery to tissues.

Background. Despite several consensus statements proposed by expert groups, including those addressing terminology, numerous authors still use different terms to describe the same pathologies associated with groin pain in athletes. The diversity of definitions and etiologies of groin pain in athletes may lead to inconsistencies in diagnostic and therapeutic strategies for athletes with groin pain syndrome.

Objective. To review and analyze current literature in order to clarify the terminology of chronic groin pain in athletes used in clinical practice, and to define the term «sports hernia» in accordance with the most recent consensus on groin pain in athletes.

Materials and methods. A narrative review was conducted using PubMed, Springer, Scopus, and Google Scholar databases to identify English-language articles describing the terminology related to chronic groin pain in athletes. The following search terms were used: «sports hernia», «athletic pubalgia», «groin pain syndrome» and «sportsman’s groin».

Results. Four consensus statements proposed by various expert groups since 2014 were identified. Groin pain in athletes is most commonly classified within the category referred to as «sports hernia». The most frequently used terms include «sports hernia», «athletic pubalgia», «sportsman’s hernia» and «core muscle injury».

Conclusion. Currently, the term «sports hernia» refers to an isolated weakness of the posterior wall of the inguinal canal, without the presence of a true anatomical hernia, leading to chronic groin pain in athletes. Because the pain is not associated with a hernia in the conventional sense, this terminology can be confusing for clinicians. Professional communities should recognize the spectrum of symptoms associated with athletic groin pain and adopt a unified terminology based on anatomical, clinical, and pathophysiological principles.

Purpose of the study: to assess the consistency of MRI interpretations among radiologists with varying levels of expertise in working with athletes when evaluating MRIs of players with acute non-contact muscle injuries (ANСMI).

Materials and methods. A retrospective review of MRI interpretation protocols for lower limb muscle injuries in adult professional football players from three prominent Russian Premier League football clubs was conducted. Reports were interpreted by general radiologists with limited experience in sports medicine (Group 1), whereas Group 2 comprised radiologists with over 10 years of experience in sports radiology. The reporting protocols included assessment of injury localization, grading of injury severity according to the respective classification system, identification of associated tendon injuries, and quantification of muscle edema volume.

Results. Out of 130 primary ANСMI cases, the British Athletic Association classification system was used by Group 1 radiologists in only 14 (10.8 %) cases, while 20 (15.4 %) reports employed the Stoller classification. The remaining 96 (73.8 %) reports did not specify any classification system. Comparative analysis of interpretations by the two groups demonstrated agreement regarding anatomical injury locations in 61.5 % of all evaluated cases (80 out of 130). No statistically significant difference was observed in the mean edema volume assessments between the groups (p = 0.075). However, when evaluating intramuscular tendon involvement, identical assessments were seen by both groups in 67 cases (59.8 %), whereas discrepancies occurred in 45 cases (40.2 %). Cohen’s κ coefficient was 0.132, indicating weak agreement beyond chance.

Conclusion. Significant variability was observed in defining the precise anatomical location of muscle injuries and in recognizing intramuscular tendon lesions between experienced sports radiologists and general radiologists without such expertise. To improve diagnostic accuracy in MRI evaluations of ANСMI within athletic populations, it is strongly recommended to involve radiologists with relevant specialization and sufficient clinical experience in sports medicine.

The aim of this study was to determine the morpho-anthropometric characteristics of the feet and lower limbs in long-distance runners and to assess the associations between foot type, medial longitudinal arch condition, and lower limb alignment.

Materials and methods: A single-center cross-sectional study was conducted including 308 runners (232 men and 76 women; mean age 38.2 ± 10.3 years). Anthropometric assessment was performed, along with determination of forefoot type, degree of flatfoot deformity, and lower limb alignment.

Results: The Egyptian foot type was identified in 42.5% of athletes, the Greek type in 30.2 %, and the square type in 27.3 %. Grade I–II flatfoot was observed in 60.7 % of participants, with significant sex-related differences in the distribution of arch deformity severity. No significant associations were found between foot type, body mass index, and medial longitudinal arch condition. Varus lower limb alignment was detected in 13.0% of runners and showed no statistically significant association with foot type or flatfoot severity.

Conclusion: Moderate degrees of arch flattening predominate among long-distance runners, while morphological foot characteristics appear relatively independent. These findings highlight the importance of comprehensive morphotype assessment of the foot in sports medicine.

Purpose of the study: To identify and analyse differences in posterior thigh muscles flexibility profiles between recreational runners on trail and road surfaces.

Methods: This study employed an observational cross-sectional design. The sampling technique used was purposive sampling, in which respondents were selected based on predefined inclusion and exclusion criteria. Posterior thigh muscles flexibility was assessed using an inclinometer through the Passive Straight Leg Raise (PSLR) test. Data were analysed using an independent t-test based on normality of distribution and homogeneity of variances.

Results: The p-value was 0.321 for the right posterior thigh muscles and 0.927 for the left, indicating no statistically significant differences in flexibility between groups.

Conclusions: The type of running surface did not demonstrate a measurable effect on posterior thigh muscle flexibility in the study population. The findings of this study underscore the importance of implementing targeted training programs aimed at both preventing injury and strengthening the posterior thigh muscles.