Physiological profile of national-level Spanish soccer referees

Background: Referees play a crucial role in soccer, although relevant key aspects of their physiological performance remain uncertain. Research question: To describe the physiological profile of national-level Spanish soccer referees. Type of study: Descriptive study. Methods: Twenty-two male referees (age: 26.0 ± 4.9 years; height: 1.76 ± 0.08m; body mass: 76.3 ± 13.1kg; body mass index: 24.4 ± 2.8kg·m-2) were the participants of the study. Referees were subjected to a medical examination to determine their basal cardiovascular, haematological, pulmonary function and echocardiographical profile. Complementarily, the referees carried out an incremental maximal treadmill test and two field tests: a repeated sprint (6 x 40 m/90s recovery) and a running test (fastest time to complete 2000m). Results: The left ventricular mass index averaged 122.3 ± 23.6g·m-2. Mean oxygen uptake (VO2max) averaged 48.7 ± 4.3ml·kg·min-1. Mean time during the repeated sprint test was 5.53 ± 0.21s, while mean time to complete the endurance test was 7 min 43s. Conclusion: The physiological profile of national-level Spanish soccer referees reveals moderate aerobic cardiac adaptations to training and match officiating. As match demands are relative to the standard of competition, the referees should increase their physiological parameters to be able to cope with the demands imposed by the players.