Hemodynamic and motion demands of soccer referees: a comparison between series A and B of the State Championship of Rio de Janeiro, Brazil

Introduction: Soccer referees need excellent conditioning to withstand the physical and psychological demands of games. Objective: To compare the hemodynamic variables, speed, cadence, and distance coursed of referees during soccer games of series A and B in Rio de Janeiro, Brazil. Material and method: The total number of decisions made during the 10 soccer matches evaluated was 1,224 observable decisions of 10 professional Soccer referees (one per soccer match: 5 in series A and 5 in series B). We used a frequency meter (Polar, model V800, PolarFlow software) and video footage of the games (Sony, model PXW-Z150, 4K). The moments considered were: the decision, 15 seconds that preceded it, and the period from the beginning of each stage to each decision. Were studied the hemodynamic [average heat rate (mean HR), maximum heart rate (HRmax), and minimum heart rate (HRmin)] and motion variables [average speed (Vmed), maximum speed (Vmax), average cadence (cadencemed), maximum cadence (cadencemax), minimum cadence (cadencemin), and distance covered]. Descriptive measures were used to present the results of the variables studied and the Student’s T-Test for independent samples to test the study hypotheses. The significance level was set at 95% (P <0.05). Results: The matches of series A had a greater number of interventions and greater hemodynamic load at the exact moment of the decision than those of series B. significantly (P <0.05): mean HR, HRmax, HRmin, Vmax, Cadencemed, and Cadencemax in series A were higher compared to series B. In the 15 seconds before the decisions: mean HR, HRmax, and HRmin in series A were higher than in series B, and Vmed in series B was higher in relation to series A. At the exact moment of the decisions: mean HR in series A was higher in relation to series B. Conclusion: Referees’ interventions are generally carried out under high hemodynamic pressure. The matches played in the A series require a higher number of interventions and hemodynamic intensity than the matches in the series B under high hemodynamic pressure, other psychological factors may play a role; however, this needs to be studied in greater depth.