Study on Characteristics of Exercise Load of Football Referees on the Spot

In this study, by collecting the data of running distance, heart rate index and rating of perceived exertion (RPE) index of China's national and first-level chief referees in different competitions, the load difference of chief referees in officiating competitions was scientifically quantified. The chief referee of football was taken as research object, including 6 first-class referees registered by Chinese Football Association and 12 national referees. The experimental test method was applied in the study to monitor the internal and external loads of the referee wearing Polar heart rate band and Catapult OptimEyeS5 equipment during competition, and give the subjective fatigue scale of the referee measured by rating of perceived exertion (RPE) scale before and after the match. Statistical Product and Service Solutions (SPSS) software was employed for statistical analysis of the data collected through experimental tests: The independent sample T test was conducted for the mean values of all running distances of the first level referees and the national referees in the provincial governor cup and the national referees in the provincial governor cup and the U20 under different running forms (sprint, high speed, medium speed, low speed, jogging). The independent sample T test was performed for the mean distribution proportion of the maximum heart rate (HR Max) interval (low intensity heart rate, medium and low intensity heart rate, medium intensity heart rate, medium and high intensity heart rate, and high intensity heart rate). The mean value of running distance of all fields and the subjective fatigue value of different acceleration interval were tested by the independent sample T test, and the significant difference of running distance between the whole field and the half court was analyzed. Paired sample T was used to test whether there were any differences in the indexes of the second half of the same game. Results show that there was no difference in the exercise load of the chief referee in the first and second half of the judging process. The national umpire's exercise load at the U20 is greater than that at the governor cup. The running distance of the first-class judges is 344 meters higher than that of the national judges in low intensity running, and 193 meters higher than that of the national referees in medium intensity running. The main difference centered on the second half. The proportion of lowintensity heart rate of national referees reached 73.4%, while that of first-class referees reached 58.8%. The running distance of second-half low-intensity acceleration of first-class referees was 2,440 meters, higher than that of national referees. When the national referee and the first-class judge adjudicate the same competition, the sports load of the former is lower than the latter. When they are in the U20 competition, the total running distance reached 8,910 meters, higher than that in governor cup, the running distance of low intensity was 699 meters, the running distance of medium intensity was 398 meters, and the running distance of high intensity was 208 meters. The running amount and load were both higher than that in governor cup. During the U20 competition, the average heart rate was 161.4 times/min, the maximum heart rate was 189.5 times/min in the second half, the proportion of lowintensity heart rate was 27.0%, and the proportion of low-intensity heart rate was 73.2%, both higher than that of governor cup. The running distance of low-intensity acceleration reached 5,113 meters, higher than that of the governor cup.