Body Composition as a Factor of Variability in Sensorimotor Reactions of Esports Athletes, IT Specialists, and Untrained Individuals

Background and Study Aim. Modern professional and sporting activities, particularly in esports and the IT sector, impose high requirements on the speed, accuracy, and stability of sensorimotor reactions. At the same time, reduced habitual physical activity and changes in body composition may impair psychophysiological functioning. Although sensorimotor reactions and morphofunctional indicators have been studied separately, their interrelationship in people with different activity profiles remains insufficiently explored. The purpose of this study was to determine relationships between psychophysiological indices and functional characteristics in groups with predominantly sedentary lifestyles and to evaluate how these factors affect the stability, speed, and accuracy of sensorimotor reactions. Material and Methods. Forty-one males aged 17-25 years participated: esports athletes (EA, n=14), IT specialists (IT, n=13), and untrained participants (UT, n=14). Simple visual-motor reaction (SVMR) and choice reactions of different complexity (CRT1-3: one of three signals; CRT2-3: two of three signals) were assessed using the Diagnost-1 hardware-software system. Body composition was determined by bioelectrical impedance analysis (Tanita BC-418MA). Non-parametric statistics (Mann-Whitney and Kruskal-Wallis tests) and Spearman correlation analysis were applied; the significance level was set at p<0.05. Results. Intergroup differences were found for age, sports experience, and body composition. The IT group had higher body mass, fat mass, and percentage body fat than esports athletes (p<0.05), whereas untrained participants demonstrated greater sports experience and lower fat-related indices (p<0.05). Esports athletes showed shorter reaction latencies and lower motor-component times than untrained participants, particularly in more complex choice tasks (p<0.05-0.01). Reaction-time variability parameters correlated positively with fat-related indices (r=0.56-0.64; p<0.05). In contrast, fat-free mass and total body water were negatively associated with time and variability parameters of complex choice reactions (r=-0.69; p<0.01). Conclusions. Body composition is an important determinant of the speed, stability, and efficiency of sensorimotor reactions. A higher fat component is associated with greater variability and slower responding, whereas higher fat-free mass and a more favorable hydration status exert a stabilizing effect on psychophysiological indices. These findings should be considered when assessing the functional state of esports athletes and people in intellectually demanding, predominantly sedentary occupations, and when developing programs to prevent hypodynamia.